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Exercise facilitates cerebral lactate uptake, likely by increasing arterial lactate concentration and hence the diffusion gradient across the blood brain barrier. However, non-specific β-adrenergic blockade by propranolol has previously reduced the arterio-jugular venous lactate difference (AVLac) during exercise, suggesting β-adrenergic control of cerebral lactate uptake. Alternatively, we hypothesize that propranolol reduces cerebral lactate uptake by decreasing arterial lactate concentration. To test that hypothesis, we evaluated cerebral lactate uptake taking changes in arterial concentration into account. Nine healthy males performed incremental cycling exercise to exhaustion with and without intravenous propranolol (18.7 ± 1.9 mg). Lactate concentration was determined in arterial and internal jugular venous blood at the end of each workload. To take changes in arterial lactate into account we calculated the fractional extraction (FELac) defined as AVLac divided by the arterial lactate concentration. Arterial lactate concentration was reduced by propranolol at any workload (p-1 during maximal exercise without and with propranolol, respectively. While AVLac and FELac increased during exercise (both P < 0.05), they were both unaffected by propranolol at any workload (P = 0.68 and P = 0.26) or for any given arterial lactate concentration (P = 0.78 and P = 0.22). These findings support that, while propranolol may reduce cerebral lactate uptake, this effect reflects the propranolol-induced reduction in arterial lactate concentration and not inhibition of a β-adrenergic mechanism within the brain. We hence conclude that cerebral lactate uptake during exercise is directly driven by the increasing arterial concentration with work rate.

To investigate acute changes in biochemical markers of bone and cartilage turnover in response to moderate intensity exercise with and without joint impact in healthy human subjects. A randomized, cross-over, exploratory, clinical study was conducted. Twenty healthy subjects with no history of joint trauma completed 30 min interventions of standardized moderate intensity cycling and running as well as a resting intervention 1 week apart. Blood samples were taken immediately before, four times after exercise and again the next day. Urine was sampled, before, after and the next day. On the day of rest, samples were taken at timepoints similar to the days of exercise. Markers of type I (CTX-I), II (C2M, CTX-II) and VI (C6M) collagen degradation, cartilage oligomeric matrix protein (COMP) and procollagen C-2 (PRO-C2) was measured. Trial registration number: NCT04542655, 02 September 2020, retrospectively registered. CTX-I was different from cycling (4.2%, 95%CI: 0.4–8.0%, p = 0.03) and resting (6.8%, 95%CI: 2.9–10.7%, p = 0.001) after running and the mean change in COMP was different from cycling (10.3%, 95%CI: 1.1–19.5%, p = 0.03), but not from resting (8.6%, 95%CI: − 0.7–17.8%, p = 0.07) after running. Overall, changes in other biomarkers were not different between interventions. In this exploratory study, running, but not cycling, at a moderate intensity and duration induced acute changes in biomarkers of bone and cartilage extra-cellular matrix turnover.

The aim of this study is to provide a more accurate representation of COVID-19's case fatality rate (CFR) by performing meta-analyses by continents and income, and by comparing the result with pooled estimates. We used multiple worldwide data sources on COVID-19 for every country reporting COVID-19 cases. On the basis of data, we performed random and fixed meta-analyses for CFR of COVID-19 by continents and income according to each individual calendar date. CFR was estimated based on the different geographical regions and levels of income using three models: pooled estimates, fixed- and random-model. In Asia, all three types of CFR initially remained approximately between 2.0% and 3.0%. In the case of pooled estimates and the fixed model results, CFR increased to 4.0%, by then gradually decreasing, while in the case of random-model, CFR remained under 2.0%. Similarly, in Europe, initially, the two types of CFR peaked at 9.0% and 10.0%, respectively. The random-model results showed an increase near 5.0%. In high-income countries, pooled estimates and fixed-model showed gradually increasing trends with a final pooled estimates and random-model reached about 8.0% and 4.0%, respectively. In middle-income, the pooled estimates and fixed-model have gradually increased reaching up to 4.5%. in low-income countries, CFRs remained similar between 1.5% and 3.0%. Our study emphasizes that COVID-19 CFR is not a fixed or static value. Rather, it is a dynamic estimate that changes with time, population, socioeconomic factors, and the mitigatory efforts of individual countries.

BACKGROUND During vascular surgery, restricted red-cell transfusion reduces frontal lobe oxygen (ScO2 ) saturation as determined by near-infrared spectroscopy. We evaluated whether inadequate increase in cardiac output (CO) following haemodilution explains reduction in ScO2 . METHODS This is a post-hoc analysis of data from the Transfusion in Vascular surgery (TV) Trial where patients were randomized on haemoglobin drop below 9.7 g/dL to red-cell transfusion at haemoglobin below 8.0 (low-trigger) vs 9.7 g/dL (high-trigger). Fluid administration was guided by optimizing stroke volume. We compared mean intraoperative levels of CO, haemoglobin, oxygen delivery, and CO at nadir ScO2 with linear regression adjusted for age, operation type and baseline. Data for 46 patients randomized before end of surgery were included for analysis. RESULTS The low-trigger resulted in a 7.1% lower mean intraoperative haemoglobin level (mean difference, -0.74 g/dL; P

What is the central question in this study? Atrial natriuretic peptide (ANP) is secreted in response to atrial wall distension and thus allows for evaluation, albeit indirect, of the central blood volume. Adrenaline has chronotropic and inotropic effects. We evaluated whether the chronotropic and inotropic effects of adrenaline were reflected in mid-regional proANP. What is the main finding and its importance? Central blood volume remained stable with infusion of adrenaline and yet mid-regional proANP increased. Thus, the chronotropic and inotropic state of the heart or adrenaline directly induces release of ANP variants from the myocytes.Atrial natriuretic peptide (ANP) has vasodilatory, natriuretic and diuretic properties. It is secreted in response to atrial wall distension and thereby provides an indirect evaluation of central blood volume (CBV). Adrenaline has chronotropic and inotropic effects that increase cardiac output. In the present study, we evaluated whether these effects were influenced by an increase in CBV and reflected in mid-regional proANP (MR-proANP) concentrations in the circulation, a stable proxy marker of bioactive ANP. Changes in CBV were evaluated by thoracic electrical admittance and haemodynamic variables monitored by pulse-contour analysis during two intervals with graded infusion of adrenaline. Adrenaline infusion increased heart rate (by 33 ± 18%) and stroke volume (by 6 ± 13%), hence cardiac output (by 42 ± 23%; all P 0.05). The increase in cardiac output did not result from an increase in CBV, because thoracic electrical admittance remained stable (-3 ± 17%; P = 0.230). Serum MR-proANP concentrations were increased (by 26 ± 25%; P 0.001) by adrenaline infusion and remained elevated 60 min postinfusion. We conclude that MR-proANP in the circulation is affected not only by CBV, but also by increased chronotropy/inotropy of the heart, or that adrenaline directly induces release of ANP variants from the myocytes.

Ageing reduces cerebral blood flow (CBF), while mean arterial pressure (MAP) becomes elevated. According to 'the selfish brain' hypothesis of hypertension, a reduction in vertebral artery blood flow (VA) leads to increased sympathetic activity and thus increases MAP. In twenty-two young (24 ± 3 years; mean ± SD) and eleven elderly (70 ± 5 years) normotensive men, duplex ultrasound evaluated whether the age-related reduction in CBF affects VA more than internal carotid artery (ICA) blood flow. Pulse-contour analysis evaluated MAP while near-infrared spectroscopy determined frontal lobe oxygenation and transcranial Doppler middle cerebral artery mean blood velocity (MCA Vmean ). During supine rest, MAP (90 ± 13 versus 78 ± 9 mmHg; P

Angina and no obstructive coronary artery disease (CAD) have an unfavorable prognosis, possibly due to diffuse myocardial fibrosis (DMF). In DMF the proteoglycans biglycan and versican are actively remodeled by matrix metalloproteinase. We investigated biglycan and versican in females with angina and possible DMF assessed by cardiac magnetic resonance (CMR). Seventy-one females with angina and no obstructive CAD were included. Asymptomatic females served as controls. Versican and biglycan were measured and CMR was performed measuring extracellular volume. Biglycan and versican levels were higher in symptomatic females compared with controls; 31.4 ng/mL vs. 16.4 ng/mL (p < 0.001) and 2.1 ng/mL vs. 1.8 ng/mL (p < 0.001) and moderately correlated to extracellular volume (r2 = 0.38, p

Background Women with angina and no obstructive coronary artery disease (CAD) have an unfavourable prognosis, possibly due to coronary microvascular disease and diffuse myocardial fibrosis (DMF). In DMF myocardial extracellular matrix (ECM) proteins are actively remodeled by matrix metalloproteinase (MMP). Purpose We investigated MMP-mediated degradation of the protegoglycans biglycan and versican in women with angina pectoris and possible DMF assessed by cardiac magnetic resonance T1 mapping. Methods Seventy-one women with angina pectoris and no obstructive CAD were included. Asymptomatic age-matched women served as controls (n=32). Versican and biglycan were measured in serum by specific competitive enzyme-linked immunosorbent assays. T1 mapping was performed by cardiac magnetic resonance with gadolinium measuring T1 and extracellular volume (ECV). Results Both biglycan and versican levels were higher in symptomatic women compared with controls; 31.4 ng/mL vs. 16.4 ng/mL (p Conclusion Turnover of biglycan and versican was increased in symptomatic compared to asymptomatic women and associated to ECV, supporting a link between angina with no obstructive CAD and fibrotic cardiac remodeling. The examined biomarkers may prove to be suitable for monitoring active ECM remodeling. Figure 1. Levels of BGM and VCANM Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): This work was supported by The Danish Heart Foundation, the Danish Research Fund (Den Danske Forskningsfond) and by University of Copenhagen.

Summary Objective To propose a standardized model for exercise-induced cartilage turnover and investigate residual levels and dynamics of biomarker serum ARGS (sARGS) in primary osteoarthritis (OA) patients and a supportive group of young healthy subjects. Method The trial is a randomized, cross-over, exploratory study with interventions of exercise and inactivity. 20 subjects with knee OA, as well as 20 young healthy subjects (mean age 25.7 years (range; 19–30), 50% male), underwent cycling, running and resting interventions on separate days one week apart. Blood samples were taken at baseline, immediately, 1, 2, 3 and 24 h after activity start. sARGS was measured by sandwich ELISA. Results Intraclass correlation between visits were 0.97 and 0.77 for the OA and healthy group, respectively. An acute drop in sARGS in response to high-intensity exercise was observed in both groups. Minute acute sARGS increase was observed in OA subjects in response to moderate intensity running and cycling, which normalized within 24 h. In healthy subjects an acute drop in sARGS was seen immediately after running, but not cycling, and no other changes were observed. A negative correlation between baseline Kellgren-Lawrence (KL) grade and baseline sARGS (r = −0.69, p = 0.002) in OA was found. A negative correlation between age and sARGS was found in healthy subjects (r = −0.67, p = Conclusion sARGS sensitivity to physical activity is considered low and sARGS is a reproducible and stable marker. Minute acute increases in sARGS were observed in the hours following moderate intensity exercise.

This study investigated the association between body composition and risk of atrial fibrillation (AF) in postmenopausal women. In a retrospective analysis we assessed data from 5704 postmenopausal women (age 70.7 ± 6.5 yrs.) who in 1999–2001 participated in The Prospective Epidemiological Risk Factor study with body composition assessed by dual-energy X-ray absorptiometry. Outcomes were obtained from Danish Health Registries and body composition association to risk of AF was evaluated by univariable and multivariable Cox Hazard regression. 850 women developed AF after baseline. High lean body mass was associated with increased risk of AF in multivariable analyses, adjusting for body mass index (BMI), height or weight (adjusted for: BMI, hazard ratio (HR) 1.49, 95% Confidence Interval (1.22–1.80); height, HR 1.27 (1.03–1.56); weight, 1.33 (1.06–1.65)). Height and weight were associated with increased risk of AF in multivariable analyses adjusting for body composition measures. When adjusting for total lean mass, only height remained statistically significant (HR 1.34 (1.09–1.64)). In a cohort of elderly Caucasian women, high lean body mass, height and weight were associated with increased risk of AF and the variables remained significant after adjusting for age and other known risk factors of AF.

Aim: To estimate the frequency and localization of acute (traumatic) and chronic (overuse) injuries in a population of masters rowers with respect to their age subgroups and assess the association between injury occurrence and different training modalities, rowing experience, previous competition level, and current rowing practice. Methods: A cross-sectional study was conducted among 743 masters rowers who participated in the 34th International Federation of Rowing Associations (Fédération Internationale des Sociétés d’Aviron, FISA) World Rowing Masters Regatta held in Zagreb, September 2-9, 2007. A rowingspecific questionnaire was used, followed by an interview about the injuries sustained during the 12-month period before the competition. Results: The mean injury rate per year was 0.48 injuries/ masters rower (2.25 injuries/1000 training sessions/rower). The majority of injuries were chronic injuries (the ratio of acute to chronic injuries was 1:1.7), and did not lead to the loss of training/competition time. Of all acute injuries, 49.6% were acquired during rowing-specific training, 43.7% during cross-training, and 6.7% in the gym. The most commonly affected region was the low back (32.6%), followed by the knee (14.2%), shoulder/upper arm, and elbow (10.6% each). Conclusion: International masters rowers sustained predominantly chronic injuries of low severity, and the most commonly injured region was the low back. The mean injury rate per rower per year was lower than the rates previously reported for juniors and seniors.

This study examined to what extent the human cerebral and femoral circulation contribute to free radical formation during basal and exercise-induced responses to hypoxia. Healthy participants (5♂, 5♀) were randomly assigned single-blinded to normoxic (21% O2) and hypoxic (10% O2) trials with measurements taken at rest and 30 min after cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled from the brachial artery (a), internal jugular and femoral veins (v) for non-enzymatic antioxidants (HPLC), ascorbate radical (A•-, electron paramagnetic resonance spectroscopy), lipid hydroperoxides (LOOH) and low density lipoprotein (LDL) oxidation (spectrophotometry). Cerebral and femoral venous blood flow was evaluated by transcranial Doppler ultrasound (CBF) and constant infusion thermodilution (FBF). With 3 participants lost to follow up (final n = 4♂, 3♀), hypoxia increased CBF and FBF (P = 0.041 vs. normoxia) with further elevations in FBF during exercise (P = 0.002 vs. rest). Cerebral and femoral ascorbate and α-tocopherol consumption (v a) and increased LDL oxidation during hypoxia (P < 0.043-0.049 vs. normoxia) implying free radical-mediated lipid peroxidation subsequent to inadequate antioxidant defense. This was pronounced during exercise across the femoral circulation in proportion to the increase in local O2 uptake (r = -0.397 to -0.459, P = 0.037-0.045) but unrelated to any reduction in PO2. These findings highlight considerable regional heterogeneity in the oxidative stress response to hypoxia that may be more attributable to local differences in O2 flux than to O2 tension.

BACKGROUND The relationship between levels of extracellular matrix (ECM) turnover and mortality is currently unknown. The study aimed to determine if levels of ECM turnover are predictors of all-cause mortality in a large cohort of postmenopausal women. METHODS 5,855 postmenopausal Danish women enrolled in the Prospective Epidemiologic Risk Factor (PERF) study. Baseline demographics and serum were collected at registration. Dates of death were obtained from the Danish Death Registry. ECM turnover was evaluated by serological biomarkers measuring bone (telopeptide of type I collagen [CTX-1] and osteocalcin) and soft tissue (formation of type VI collagen [PRO-C6], MMP-degraded type IV collagen [C4M], formation of type III collagen [PRO-C3], and MMP-degraded type I collagen [C1M]) turnover. Multivariate Cox analyses were performed with 3, 5, and 15 years of follow-up. RESULTS The association of bone turnover (CTX-1 and osteocalcin) with all-cause mortality was U-shaped for all time periods. After adjustment for possible confounders, the lowest quintile of bone formation and degradation remained significant for all time periods. We observed J-shaped association between all-cause mortality and PRO-C6, C4M, and PRO-C3, and there was a linear association between C1M and all-cause mortality. After adjustment for possible confounders, the highest quintile of the soft tissue turnover biomarkers (PRO-C6, C4M, PRO-C3, and C1M) remained significantly associated with all-cause mortality for all time periods. CONCLUSION Both low and high levels of tissue turnover were associated with increased risk of all-cause mortality in postmenopausal women. Overall, these results highlight the importance of bone and soft tissue homeostasis.

Background In patients undergoing open surgery for a ruptured abdominal aortic aneurysm (rAAA), survivors demonstrate a high platelet count, and proactive administration of platelets (and fresh frozen plasma) appears to influence mortality. Objectives This trial investigated the effect of platelets administered before transport to surgery. Methods In a prospective study design, patients were randomised to receive platelets (intervention; n = 61) or no platelets (control; n = 61) before transport to vascular surgery from 11 local hospitals. The study was terminated when one of the vascular surgical centres implemented endovascular repair for rAAA patients. Results Thirty days after surgery, mortality was 36% for patients with intervention vs 31% for controls (P = 0·32). Post-operative thrombotic events (14 vs 15; P = 0·69), renal failure (11 vs 10; P = 0·15) and pulmonary insufficiency (34 vs 39; P = 0·15) were similar in the two groups of patients. No adverse reactions to platelet administration were observed. In addition, length of stay in the intensive care unit was unaffected by intervention. Conclusions For patients planned for open repair of a rAAA, we observed no significant effect of early administration of platelets with regard to post-operative complications and stay in the ICU or in hospital and also no significant effect on mortality.

High-intensity interval exercise (HIIE) improves cerebral executive function (EF), but the improvement in EF is attenuated after repeated HIIE, perhaps because of lower lactate availability for the brain. This investigation examined whether improved EF after exercise relates to brain lactate uptake. Fourteen healthy, male subjects performed 2 HIIE protocols separated by 60 min of rest. Blood samples were obtained from the right internal jugular venous bulb and from the brachial artery to determine arterial-venous differences across the brain for lactate (a-v difflactate), glucose (a-v diffglucose), oxygen (a-v diffoxygen), and brain-derived neurotrophic factor (BDNF; a-v diffBDNF). EF was evaluated by the color-word Stroop task. The first HIIE improved EF for 40 min, whereas the second HIIE improved EF only immediately after exercise. The a-v diffglucose was unchanged, whereas the a-v diffBDNF increased similarly after both HIIEs, and the a-v difflactate increased, but the increase was attenuated after the second HIIE, compared with the first HIIE ( P < 0.05). The EF after HIIE correlated with the a-v difflactate ( r2 = 0.62; P < 0.01). We propose that attenuated improvement in EF after repeated HIIE relates to reduced cerebral lactate metabolism and is, thereby, linked to systemic metabolism as an example of the lactate shuttle mechanism.-Hashimoto, T., Tsukamoto, H., Takenaka, S., Olesen, N. D., Petersen, L. G., Sorensen, H., Nielsen, H. B., Secher, N. H., Ogoh, S. Maintained exercise-enhanced brain executive function related to cerebral lactate metabolism in men.

There has been limited success with blood-based biomarkers of neurodegeneration. One perceived reason is that blood has no direct contact to the brain. Recently developed blood-based biomarkers of tau-degradation have shown promise as potential tools for peripheral assessment of neurodegeneration; however, factors contributing to the levels of these in blood are poorly understood. Using multiple linear regression analysis in cross-sectional data from an observational cohort (n = 5626), the aim was to examine which factors correlate to the serological levels of two novel biomarkers measuring truncated tau fragments (Tau-A and Tau-C) in serum. Platelets, albumin and several modifiable risk factors, including Body Mass Index, high density lipoprotein and white blood cell count were associated with the serum level of tau fragments. The factors associated with tau in serum may promote neurodegeneration and alter the permeability of the Blood Brain Barrier through chronic inflammation and vascular dysfunction. These data are of key importance for understanding the mechanism of release and subsequent peripheral processing of tau from the brain and will assist in the development of future blood-based biomarkers.

AIM To evaluate whether muscle vasodilatation plays a role for hypotension developed during central hypovolaemia, muscle oxygenation (Sm O2 ) was examined during (pre)syncope induced by head-up tilt (HUT). Skin blood flow (SkBF) and oxygenation (Sskin O2 ) were determined because evaluation of Sm O2 may be affected by superficial tissue oxygenation. Furthermore, we evaluated cerebral oxygenation (Sc O2 ) and middle cerebral artery mean blood flow velocity (MCAvmean ). METHODS Twenty healthy male volunteers (median age 24 years; range 19-38) were subjected to passive 50° HUT for 1 h or until (pre)syncope. Sc O2 and Sm O2 (near-infrared spectroscopy), MCAvmean (transcranial Doppler) along with mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) (Modelflow® ) were determined. RESULTS (Pre)syncopal symptoms appeared in 17 subjects after 11 min (median; range 2-34) accompanied by a decrease in MAP, SV, CO and TPR, while HR remained elevated. During (pre)syncope, Sc O2 decreased [73% (71-76; mean and 95% CI) to 68% (65-71), P < 0.0001] along with MCAvmean [40 (37-43) to 32 (29-35) cm s-1 , P < 0.0001]. In contrast, Sm O2 increased [63 (56-69)% to 71% (65-78), P < 0.0001], while Sskin O2 [64% (58-69) to 53% (47-58), P < 0.0001] and SkBF [71 (44-98) compared to a baseline of 99 (72-125) units, P = 0.020] were reduced. CONCLUSION We confirm that the decrease in MAP during HUT is associated with a reduction in indices of cerebral perfusion. (Pre)syncope was associated with an increase in Sm O2 despite reduced Sskin O2 and SkBF, supporting that muscle vasodilation plays an important role in the circulatory events leading to hypotension during HUT.

Background: The mechanisms underlying red blood cell (RBC)–mediated hypoxic vasodilation remain controversial, with separate roles for nitrite ( ) and S -nitrosohemoglobin (SNO-Hb) widely contested given their ability to transduce nitric oxide bioactivity within the microcirculation. To establish their relative contribution in vivo, we quantified arterial-venous concentration gradients across the human cerebral and femoral circulation at rest and during exercise, an ideal model system characterized by physiological extremes of O 2 tension and blood flow. Methods: Ten healthy participants (5 men, 5 women) aged 24±4 (mean±SD) years old were randomly assigned to a normoxic (21% O 2 ) and hypoxic (10% O 2 ) trial with measurements performed at rest and after 30 minutes of cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled simultaneously from the brachial artery and internal jugular and femoral veins with plasma and RBC nitric oxide metabolites measured by tri-iodide reductive chemiluminescence. Blood flow was determined by transcranial Doppler ultrasound (cerebral blood flow) and constant infusion thermodilution (femoral blood flow) with net exchange calculated via the Fick principle. Results: Hypoxia was associated with a mild increase in both cerebral blood flow and femoral blood flow ( P P r =0.680–0.769, P gradients reflecting consumption (arterial>venous; P arterial; P P P P S -nitrosothiols ( P >0.05). Conclusions: These findings suggest that hypoxia and, to a far greater extent, exercise independently promote arterial-venous delivery gradients of intravascular nitric oxide, with deoxyhemoglobin-mediated reduction identified as the dominant mechanism underlying hypoxic vasodilation.

Studies with direct measures of body fat distribution are required to explore the association between central and general obesity to cancer risk in postmenopausal women. This study investigates the association between central obesity and general obesity to overall/site-specific cancer risk in postmenopausal women. The analysis included 4,679 Danish postmenopausal women. Body fat distribution was evaluated by whole-body dual-energy X-ray absorptiometry scanners. Cancer diagnoses were extracted from the Danish Cancer Registry and multivariable Cox regression models explored the association between cancer risk and central obesity after adjusting for BMI. Our results showed that high central obese women had a 50% increased risk of overall cancer relative to low central obese women (Q1vs.Q4: [HR:1.50, CI:1.20–1.88]). For site-specific cancers, central obesity was significantly associated with Respiratory (Q1vs.Q4: [HR:2.01, CI:1.17–3.47]), Gastrointestinal (Q1vs.Q4: [HR:1.55, CI:0.99–2.41]) and Female genital organs (Q1vs.Q4: [HR:1.95, CI:1.00–3.78]) cancer diagnoses. Sub-analyses stratified by smoking-habits found a significant association between central obesity and a cancer diagnosis for current (Q1vs.Q4: [HR:1.93, CI:1.25–2.99]) and former smokers (Q1vs.Q4: [HR:1.90, CI:1.23–2.94]). These analyses suggest that central obesity is associated with some cancers in postmenopausal women independent of BMI.

Background: Anoxic brain injury is the primary cause of death after resuscitation from out-of-hospital cardiac arrest (OHCA) and prognostication is challenging. The aim of this study was to evaluate the potential of two fragments of tau as serum biomarkers for neurological outcome. Methods: Single-center sub-study of 171 patients included in the Target Temperature Management (TTM) Trial randomly assigned to TTM at 33 °C or TTM at 36 °C for 24 h after OHCA. Fragments (tau-A and tau-C) of the neuronal protein tau were measured in serum 24, 48 and 72 h after OHCA. The primary endpoint was neurological outcome. Results: Median (quartile 1 - quartile 3) tau-A (ng/ml) values were 58 (43-71) versus 51 (43-67), 72 (57-84) versus 71 (59-82) and 76 (61-92) versus 75 (64-89) for good versus unfavourable outcome at 24, 48 and 72 h, respectively (pgroup = 0.95). Median tau C (ng/ml) values were 38 (29-50) versus 36 (29-49), 49 (38-58) versus 48 (33-59) and 48 (39-59) versus 48 (36-62) (pgroup = 0.95). Tau-A and tau-C did not predict neurological outcome (area under the receiver-operating curve at 48 h; tau-A: 0.51 and tau-C: 0.51). Conclusions: Serum levels of tau fragments were unable to predict neurological outcome after OHCA.

BACKGROUND Gly16arg polymorphism of the adrenergic β2-receptor is associated with the elevated cardiac output (Q) in healthy gly16-homozygotic subjects. We questioned whether this polymorphism also affects Q and regional cerebral oxygen saturation (SCO2) during anesthesia in vascular surgical patients. METHODS One hundred sixty-eight patients (age 71 ± 6 years) admitted for elective surgery were included. Cardiovascular variables were determined before and during anesthesia by intravascular pulse contour analysis (Nexfin) and SCO2 by cerebral oximetry (INVOS 5100C). Genotyping was performed with the TaqMan assay. RESULTS Before anesthesia, Q and SCO2 were 4.7 ± 1.2 L/min and 66% ± 8%, respectively, and linearly correlated (r = 0.35, P < .0001). In patients with the gly16gly genotype baseline, Q was approximately 0.4 L/min greater than in arg16 carriers (CI95: 0.0-0.8, Pt test = .03), but during anesthesia, the difference was 0.3 L/min (Pmixed-model = .07). Post hoc analysis revealed the change in SCO2 from baseline to the induction of anesthesia to be on average 2% greater in gly16gly homozygotes than in arg16 patients when adjusted for the change in Q (P = .03; CI95: 0.2-4.0%). CONCLUSIONS This study suggests that the β2-adrenoceptor gly16gly genotype is associated with the elevated resting Q. An interesting trend to greater frontal lobe oxygenation at induction of anesthesia in patients with gly16gly genotype was found, but because of insufficient sample size and lack of PCO2 control throughout the measurements, the presented data may only serve as the hypothesis generating for future studies. The confidence limits indicate that the magnitude of the effects may range from clinically insignificant to potentially important.

BACKGROUND:Arterial hypotension is frequent in patients undergoing anesthesia and may aggravate the outcome. Common genetic variations may influence the cardiovascular response to anesthesia. In this retrospective cohort study, we tested whether variation in the gene encoding the β2-adrenergic recep

Background:Development of improved topical treatments of painful joints is warranted. A novel diclofenac sodium gel formulation, AMZ001, has been developed with the purpose of improving 1) The onset and duration of pain relief, and 2) The ease of use by reducing the required daily frequency of gel application. Previous trials in human subjects have confirmed improved permeability of a reduced volume of AMZ001 gel as compared to approved diclofenac topical products with a comparable safety and tolerability profile, supporting trials to evaluate the efficacy and safety of AMZ001 in painful joint conditions.Objectives:The current abstract reports the main results of a randomized trial of AMZ001 once or twice daily application versus placebo in symptomatic knee osteoarthritis.Methods:The trial was a placebo-controlled, parallel group, double-blind, randomized trial to evaluate the efficacy and safety of AMZ001 or placebo in subjects with knee osteoarthritis. The main inclusion criteria were Kellgren-Lawrence radiographic severity of 1-3, and pain ≥40 and ≤90 out of 100 using the WOMAC pain subscale (5 questions) at the time of screening. The subjects were randomized to apply AMZ001 gel once (QD) or twice (BID) daily or placebo twice daily per OA knee for a period of 28 days, or to apply Voltaren® Gel 1 % four times daily (QID) in a single-blind fashion for exploratory comparison. The primary endpoint was change from baseline at week 4 in WOMAC pain (5 questions). The main secondary endpoints included WOMAC subscales, Patient Global Assessment (PGA) and quality of life using the EQ-5D. In addition to the main analysis, a post-hoc subgroup analysis of subjects meeting the pain criterion at both screening and baseline was performed.Results:A total of 444 subjects were randomized. The main baseline characteristics were well balanced between treatment groups.AMZ001 QD and BID led to statistically significant reductions in pain compared to baseline with an estimated difference (95% CI) normalized to 0-100 at week 4 of -27.33 (-30.50, -24.17), and -26.49 (-29.60, -23.38), respectively. Reduction in pain at week 4 was statistically significantly superior to placebo for AMZ001 QD (p=0.04), and borderline significant for AMZ001 BID (pBoth AMZ001 QD and BID led to statistically significant improvements in PGA at week 4 compared to placebo (pWhile the study design and differences in sample sizes does not allow formal comparisons between the double- and single blinded groups, the exploratory comparator, Voltaren QID, did not reach statistically significant differences to placebo or AMZ001 in any of the endpoints, in neither the ITT nor the subgroup analyses.The safety and tolerability of AMZ001 was favorable, as the frequency of AEs leading to discontinuation of treatment was similarly low (ranging between 2.8 % to 6.6 %) between AMZ001 once or twice daily and placebo or Voltaren Gel 1%. The most common treatment-emergent AEs were application site dryness, and application site erythema. No serious adverse events were reported during the trial.Conclusion:AMZ001, a novel topical diclofenac formulation, either once or twice daily was efficacious in the treatment of knee OA pain with a good tolerability and safety profile, suggesting AMZ001 may be a promising alternative to existing pain-relieving treatments in knee OA.References:NADisclosure of Interests:Asger Bihlet Shareholder of: Nordic Bioscience, Consultant of: Amzell BV, Medivir AB, Xintela AB, Merck KGaA, Employee of: Nordic Bioscience, Inger Byrjalsen Employee of: Nordic Bioscience, Henning Bay Nielsen: None declared, Jeppe Andersen Shareholder of: Minor shareholder of Nordic Bioscience, Consultant of: Medivir AB, Xintela AB, Employee of: Nordic Bioscience, Laetitia Delpy Employee of: Amzell BV, Caroline Derne Employee of: Amzell BV, Dario Carrara Employee of: Amzell BV

Background:Exercise is recommended in osteoarthritis (OA) to limit pain and preserve joint function. Cycling is considered healthy, while the safety of running in OA has been controversial. The acute impact on cartilage in response to exercise (weight bearing vs non-weight bearing) remains to be explored.Biomarkers originating from type I-III and VI collagen can be measured in serum and urine and may reflect cartilage turnover.We report the first ever data on acute effects of exercise on a panel of collagen biomarkers in OA.Objectives:To investigate the effect of running vs cycling on biomarkers of collagen type I-III and VI reflecting cartilage turnover.Methods:We conducted a randomized, crossover clinical study (approval number: H-18038807) of subjects with primary knee OA. Screening included a maximal heart rate test to standardize exercise intensity. Participants underwent 30 minutes of running and cycling on separate days with blood samples taken at baseline and 0.5, 1, 2 and 3 hours after exercise initiation and again 24 hours after the exercise in order to evaluate the dynamic levels of biomarkers. Urine samples were collected before exercise and approximately 1 hour and 24 hours after. Potential diurnal variation was taken into account by measurements at comparable times from participants on a separate day with no exercise (resting). Levels of serum CTX-I, C2M, C3M, C6M and urine CTX-II were measured by enzyme-linked immunosorbent assays.Biomarker dynamics were plotted. Error bars represent 95% CI. CTX-I and C6M are displayed.Results:20 subjects were included of which 20 completed cycling and resting and 15 completed running. Subject characteristics displayed in table.CTX-I decreased significantly from baseline at three hours after both running (pC2M was decreased at 1 hour after running (Change: -9.4%, 95%CI: -18.4--1.0, pC3M was decreased at 2 hours after cycling (Change: -6.3%, 95%CI: -12.1--0.5, pC6M was increased at 1 hour after initiating rest and decreased 1 and 2 hours after running (pThe variation in CTX-II was higher, compared with the serum-based markers. A trend of decreasing CTX-II in response to rest was observed, but no significant changes were seen in response to exercise.GroupCycling/Resting(N = 20)Running(N = 15)Mean age, years (SD)61.8 (9.1)61.9 (7.5)Male sex, n (%)5 (25)4 (26.6)Mean BMI (kg/m2) (SD)26.3 (3.4)26.5 (3.6)Baseline KL-grade, n (%)1: 3 (15.0)2: 8 (40.0)3: 9 (45.0)1: 2 (13.3)2: 8 (53.3)3: 5 (33.3)Conclusion:Cycling and running acutely influenced markers of type I-III and VI collagen. The results suggest no harmful effects on bone and cartilage in OA. The sensitivity of biomarkers to physical activity and inactivity is important to take into account, when using them in clinical research.Disclosure of Interests:Jonathan Bjerre-Bastos: None declared, Henning Bay Nielsen: None declared, Abigail Mackey: None declared, Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S., Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S., Jeppe Ragnar Andersen Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee of Nordic Bioscience., Mikael Boesen Consultant of: AbbVie, AstraZeneca, Eli Lilly, Esaote, Glenmark, Novartis, Pfizer, UCB, Paid instructor for: IAG, Image Analysis Group, AbbVie, Eli Lilly, AstraZeneca, esaote, Glenmark, Novartis, Pfizer, UCB (scientific advisor)., Speakers bureau: Eli Lilly, Esaote, Novartis, Pfizer, UCB, Yi He Employee of: YH is a full time employee of Nordic Bioscience A/S, Asger Reinstrup Bihlet Shareholder of: Nordic Bioscience A/S.

Current guidelines advocate to limit red blood cell (RBC) transfusion during surgery, but the feasibility and safety of such a strategy remain unclear, as the majority of evidence is based on postoperatively stable patients. We assessed the effects of a protocol aiming to restrict RBC transfusion throughout hospitalization for vascular surgery. Fifty-eight patients scheduled for lower limb bypass or open abdominal aortic aneurysm repair were randomly assigned, on hemoglobin drop below 9.7 g/dL, to either a low-trigger (hemoglobin < 8.0 g/dL) or a high-trigger (hemoglobin < 9.7 g/dL) group for RBC transfusion. Near-infrared spectroscopy assessed intraoperative oxygen desaturation in brain and muscle. Explorative outcomes included nationwide registry data on death and major vascular complications. The primary outcome, mean hemoglobin within 15 days of surgery, was significantly lower in the low-trigger group, at 9.46 vs 10.33 g/dL in the high-trigger group (mean difference, −0.87 g/dL; P = .022), as were units of RBCs transfused (median [interquartile range (IQR)], 1 [0-2] vs 3 [2-6]; P = .0015). Although the duration and magnitude of cerebral oxygen desaturation increased in the low-trigger group (median [IQR], 421 [42-888] vs 127 [11-331] minutes × %; P = .0036), muscle oxygenation was unaffected. The low-trigger group associated to a higher rate of death or major vascular complications (19/29 vs 8/29; hazard ratio, 3.20; P = .006) and fewer days alive outside the hospital within 90 days (median [IQR], 76 [67-82] vs 82 [76-84] days; P = .049). In conclusion, a perioperative protocol restricting RBC transfusion successfully separated hemoglobin levels and RBC units transfused. Exploratory outcomes suggested potential harm with the low-trigger group and warrant further trials before such a strategy is universally adopted. This trial was registered at www.clinicaltrials.gov as #NCT02465125.

INTRODUCTION High-intensity interval exercise (HIIE) is more effective at increasing metabolic and cardiovascular health compared with moderate-intensity continuous exercise for patients with cardiovascular disease, but exhaustive high-intensity continuous exercise attenuates dynamic cerebral autoregulation (CA). This study assessed the effect of HIIE on dynamic CA. METHODS Nine healthy men (age, 24 ± 3 yr; mean ± SD) warmed up at 50%-60% maximal workload (Wmax) for 5 min before HIIE including four 4-min bouts of exercise at 80%-90% Wmax interspaced by four 3-min bouts at 50% to 60% Wmax. Transcranial Doppler determined middle cerebral artery mean blood velocity (MCA Vmean), and brachial artery catheterization determined mean arterial pressure (MAP). Dynamic CA was evaluated by transfer function analysis of changes in MAP and MCA Vmean. RESULTS The HIIE increased MAP (from 92 ± 9 to 104 ± 10 mm Hg; P < 0.0125), whereas MCA Vmean did not change. Transfer function phase increased and coherence decreased during HIIE (P < 0.0125 vs rest, respectively), whereas gain was unchanged. CONCLUSIONS The results suggest that dynamic CA is unaffected during HIIE, indicating that the brain is protected from fluctuations in MAP. Thus, we propose that HIIE may be beneficial for brain-related health as maintenance of cerebral perfusion in contrast to high-intensity continuous exercise.

This study evaluated by thrombelastography® (TEG) and Multiplate® analyses the role of the spleen and the liver for adrenaline-induced enhanced hemostatic competence. Eight splenectomized subjects and eight matched healthy control subjects were exposed to one-hour infusion of adrenaline (6 μg/kg/h). Administration of adrenaline to the healthy subjects reduced time to TEG-detected initial fibrin formation (by 22%) and increased rate of clot development (by 10%), maximal amplitude (by 8%), platelet count (by 30%), and Multiplate evaluated Ristocetin-induced platelet aggregation (by 21%) (all p ≤ 0.05), but infusion of adrenaline did not result in significant arterial to liver vein differences for plasma markers of coagulation. In the splenectomized subjects, adrenaline reduced the TEG-determined time to initial fibrin formation (by 17%; p = 0.005) whereas rate of clot development and maximum amplitude were unaffected. Also, 6 patients undergoing liver transplantation were exposed to infusion of adrenaline (4.8 μg/kg/h) during the anhepatic phase of the operation and that increased TEG-determined rate of clot formation (by 10%; p 0.05), maximal amplitude (by 9%; p = 0.002) and tended to reduce time to initial fibrin formation (p = 0.1). In conclusion, adrenaline enhances hemostasis as evaluated by TEG in both healthy subjects and in anhepatic patients during liver transplantation and Ristocetin-induced aggregation in control subjects. In contrast, infusion of adrenaline reduces only time to initial fibrin formation in splenectomized subjects. These findings suggest that mobilization of platelets from the spleen dominates the adrenaline-induced enhanced hemostatic competence.

Background. Open abdominal aortic aneurysm repair is often followed by elevated plasma creatinine, likely due to impaired renal blood flow. We evaluated whether postoperative elevation in creatinine relates to renal oxygen extraction during surgery as an index of renal blood flow and also monitored frontal lobe oxygenation. Methods. For 19 patients (66 ± 10 years; mean ± SD) undergoing open infrarenal abdominal aortic aneurysm repair, renal oxygen extraction was determined by arterial and renal vein catheterization. Near-infrared spectroscopy determined frontal lobe oxygenation. Results. During surgery mean arterial pressure (from 102 ± 14 to 65 ± 11 mm Hg; P < .0001), arterial hemoglobin (from 7.7 ± 0.7 to 6.6 ± 0.8 mmol/L; P < 0.0001), and frontal lobe oxygenation (from 74 ± 6% to 70 ± 6%; P = .0414) decreased, while renal oxygen extraction increased (from 5.3% [4.3-8.1]; median [interquartile range] to 10.8% [5.8-17.5]; P = .0405). Plasma creatinine became significantly elevated on the second day after the operation (from 83 [73-101] to 105 µmol/L [79-143]; P = .0062) with a peak increase observed after 2 days (1-2). The peak increase in creatinine correlated to intraoperative renal oxygen extraction ( r = 0.51; P = .026). Conclusion. Kidney function was affected after open abdominal aortic aneurysm repair likely related to limited renal blood flow. We take the increase in renal oxygen extraction and reduction in frontal lobe oxygenation to suggest that mean arterial pressure and hemoglobin were too low to maintain renal and cerebral circulation in vascular surgical patients.

Background Osteoarthritis (OA) is a heterogeneous disease described by a combination of joint pain, physical disability and radiographic alterations leading to joint failure and total joint replacement (TJR). Commonly used endpoints in OA trials are worsening of pain and joint space narrowing. TJR is normally not considered an endpoint. Age and female gender are considered as major risk factors for developing OA. Objectives We hypothesise that TJR can be used as an endpoint in OA outcome studies within reasonable time frame. To investigate the basis for this hypothesis, we explored the prevalence and incidence of TJR as a reflection of joint failure in the Prospective Epidemiologic Risk Factor (PERF I) study. Methods A total of 5,855 Danish postmenopausal women aged 49–88 enrolled in the Prospective Epidemiologic Risk Factor (PERF I) study during 1999–2001 (baseline). Three, six and twelve year follow-up data from the Danish National registry was collected in end of 2014, including occurrence of TJR, OA and other relevant diagnosis. Also, women where at baseline and in 2014 asked whether they had a TJR or OA. The biomarker C1M was measured in baseline serum samples. The PERF I study was carried out in accordance with ICH-GCP and the study protocol was approved by the local ethics committees. Results There were 798 women that had their first TJR between baseline and 12 year follow-up; giving an incidence proportion of 13.6%. The TJR women were on average 1 year older (p=0.010) and heavier (1.7 kg/cm2, p 40 ng/mL, median) that after baseline underwent there first ever TJR (841). Group 1 is as described above. The 3, 6 and 12 incidence rates were 9.0, 17.3% and 29.7% for the prior TJR group, 6.2, 12.1% and 23.3% for the OA group, and 7.6, 13.6% and 25.1% for the OA +C1M group. The age-dependent prevalence and incidence for the first TJR. The prevalence was insignificant for the age group younger than 60 years old ( Conclusions Within a timeframe of 3, 6 or 12 years TJR incidence for women with an OA diagnosis reached 6, 12% and 23%, which was a doubling compared to the All population. The incidence increased by adding a single diagnostic measure. This reflects that TJRs are frequent amongst elderly women and that if designed minutiously, such as including specific diagnostic criteria (e.g. biomarker, OA diagnose), it may be feasible to conduct clinical studies with TJR as an endpoint. However, special attention much be directed to the objectiveness of the criteria for TJR. This may build a case for design of outcome studies (joint failure) for developing drugs in OA. Disclosure of Interest A. Bay-Jensen Shareholder of: Nordic Bioscience, Grant/research support from: ApproacH (IMI support), Employee of: Nordic Bioscience, C. Bager Employee of: Proscion, A. Bihlet Shareholder of: Nordic Bioscience, Employee of: Nordic Bioscience, C. Thudium Employee of: Nordic Bioscience, I. Byrjalsen Employee of: Nordic Bioscience, H. Nielsen Employee of: Nordic Bioscience, J. Andersen Shareholder of: Nordic Bioscience, Employee of: Nordic Bioscience, B. Riis Shareholder of: Nordic Bioscience, C. Christiansen Shareholder of: Nordic Bioscience, M. Karsdal Shareholder of: Nordic Bioscience, Grant/research support from: ApproacH (IMI support), Employee of: Nordic Bioscience

Aim Collagens are major cardiac extracellular matrix components, known to be actively remodelled and accumulated during diffuse myocardial fibrosis. We evaluated whether accelerated collagen turnover described by neo-epitope biomarkers reflecting collagen formation and degradation separates patients with diffuse myocardial fibrosis from asymptomatic controls. Methods and results Seventy-one women with angina pectoris without significant coronary artery disease assessed by invasive coronary angiogram were included. Competitive enzyme-linked immunosorbent assays (ELISAs) measuring circulating protein fragments in serum assessed the formation and degradation of collagen type III (Pro-C3, C3M and C3C), IV (P4NP7S and C4M), V (Pro-C5 and C5M) and VI (Pro-C6 and C6M), and degradation of collagen type I (C1M). Serum samples from 32 age-matched asymptomatic women were included as controls. Symptomatic women presented significantly elevated levels of Pro-C6, C3C, C3M, C4M and C8-C ( p Conclusion Women with angina pectoris, but without significant obstructive coronary artery disease, showed an imbalanced collagen turnover compared to asymptomatic controls. The examined biomarkers are tools to monitor active collagen remodelling in patients with angina pectoris, in risk of developing myocardial fibrosis.

The purpose was to evaluate endovascular aortic repair (EVAR) patients with known gluteal claudication using near infrared spectroscopy (NIRS), and secondly to assess the hemodynamic consequences of occluding one internal iliac artery (IIA) during EVAR. EVAR interventions with occlusion of one IIA were examined. Gluteal claudicants were recruited from the outpatient clinic at their annual EVAR control (Group A; n=7) and a second cohort was collected consecutively and prospectively before and after the intervention (Group B; n=10). A treadmill test (12% incline, 2.4 km/h) with NIRS (INVOS-5100) sensors applied bilaterally on the gluteal regions was performed. NIRS was used to asses muscle oxygenation. NIRS data was divided into baseline, exercise and recovery values. Recovery times and absolute NIRS values (oxygenation) from the two gluteal sides were compared. Mean recovery times (group A) of the occluded and patent sides were 512 sec [73-1207] and 137 sec [0-643] (p=0.046) respectively. Using 240 seconds (suggested by literature) as cut-off the sensitivity and specificity were both 71% for finding the occluded IIA. Group B revealed similar oxygenation level of the two gluteal regions pre EVAR. Post EVAR an overall absolute reduction of the oxygenation were noted and a significant difference in the recovery values of the two gluteal sides (p

During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48-83) years] ScO2, mean arterial pressure (MAP), EtCO2, and ventilation were obtained retrospectively from the anesthetic charts. By clamping the aorta, ScO2 and EtCO2 were kept stable by reducing ventilation (median, -0.8 l min(-1); interquartile range, -1.1 to -0.4; P

OBJECTIVE To evaluate effects of preoperative high-dose glucocorticoid on the inflammatory response and recovery after endovascular aortic aneurysm repair (EVAR). BACKGROUND The postimplantation syndrome after EVAR may delay recovery due to the release of proinflammatory mediators. Glucocorticoids may reduce postoperative inflammatory responses and enhance recovery, but with limited information on EVAR. METHODS A single-center, randomized, double-blind, placebo-controlled trial of 153 patients undergoing elective EVAR between November 2009 and January 2013. Patients received 30 mg/kg of methylprednisolone (MP) (n = 77) or placebo (n = 76) preoperatively. Primary outcome was a modified version of the systemic inflammatory response syndrome. Secondary outcome measures were the effect on inflammatory biomarkers, morbidity, and time to meet discharge criteria. RESULTS Of 153 randomized patients, 150 (98%) were evaluated for the primary outcome. MP reduced systemic inflammatory response syndrome from 92% to 27% (P < 0.0001) (number needed to treat = 1.5), maximal plasma interleukin 6 from 186 pg/mL [interquartile range (IQR) = 113-261 pg/mL] to 20 pg/mL (IQR = 11-28 pg/mL) (P < 0.001) and fulfillment of discharge criteria was shorter [2 days (IQR = 2-4 days) vs 3 days (IQR = 3-4 days)] (P < 0.001). C-reactive protein, temperature, interleukin 8, and soluble tumor necrosis factor receptor were also reduced (P < 0.001) by MP. Myeloperoxidase, D-dimer, and matrix metalloproteinase 9 were not modified. No differences in 30-day medical (23% vs 36%) (P = 0.1) or surgical (20% vs 21%) morbidity were found in the active group versus the placebo group. CONCLUSIONS Preoperative MP attenuates the inflammatory response with a faster recovery after EVAR for abdominal aortic aneurysms. Further safety and dose-response studies are required to allow recommendations for general practice. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00989729.

Summary Brain activation reduces balance between cerebral consumption of oxygen versus carbohydrate as expressed by the so-called cerebral oxygen-carbohydrate-index (OCI). We evaluated whether preparation for surgery, anaesthesia including tracheal intubation and surgery affect OCI. In patients undergoing aortic surgery, arterial to internal jugular venous (a-v) concentration differences for oxygen versus lactate and glucose were determined from before anaesthesia to when the patient left the recovery room. Intravenous anaesthesia was supplemented with thoracic epidural anaesthesia for open aortic surgery (n = 5) and infiltration with bupivacaine for endovascular procedures (n = 14). The a-v difference for O2 decreased throughout anaesthesia and in the recovery room (1·6 ± 1·9 versus 3·2 ± 0·8 mmol l−1, mean ± SD), and while a-v glucose decreased during surgery and into the recovery (0·4 ± 0·2 versus 0·7 ± 0·2 mmol l−1, P

We evaluated cerebral perfusion, oxygenation and metabolism in 11 young (22 ± 1 years) and nine older (66 ± 2 years) individuals at rest and during cycling exercise at low (25% W(max)), moderate (50% Wmax), high (75% W(max)) and exhaustive (100% W(max)) workloads. Mean middle cerebral artery blood velocity (MCA V(mean)), mean arterial pressure (MAP), cardiac output (CO) and partial pressure of arterial carbon dioxide (P(aCO2)) were measured. Blood samples were obtained from the right internal jugular vein and brachial artery to determine concentration differences for oxygen (O2), glucose and lactate across the brain. The molar ratio between cerebral uptake of O2 versus carbohydrate (O2-carbohydrate index; O2/[glucose + 1/2 lactate]; OCI), the cerebral metabolic rate of O2 (CMRO2) and changes in mitochondrial O2 tension ( P(mitoO2)) were calculated. 100% W(max) was ~33% lower in the older group. Exercise increased MAP and CO in both groups (P < 0.05 vs. rest), but at each intensity MAP was higher and CO lower in the older group (P < 0.05). MCA V(mean), P(aCO2) and cerebral vascular conductance index (MCA V(mean)/MAP) were lower in the older group at each exercise intensity (P < 0.05). In contrast, young and older individuals exhibited similar increases in CMRO2 (by ~30 μmol (100 g(-1)) min(-1)), and decreases in OCI (by ~1.5) and (by ~10 mmHg) during exercise at 75% W(max). Thus, despite the older group having reduced cerebral perfusion and maximal exercise capacity, cerebral oxygenation and uptake of lactate and glucose are similar during exercise in young and older individuals.

Dementia and type 2 diabetes are both characterized by long prodromal phases, challenging the study of potential risk factors and their temporal relation. The progressive relation among metabolic syndrome, insulin resistance (IR), and dementia has recently been questioned, wherefore the aim of this study was to assess the potential association among these precursors of type 2 diabetes and cognitive dysfunction. Using data from the Prospective Epidemiological Risk Factor (PERF) Study (n = 2,103), a prospective study of elderly women in Denmark, we found that impaired fasting plasma glucose concentration was associated with 44% (9–91%) larger probability of cognitive dysfunction. In addition, subjects above the HOMA-IR threshold (HOMA-IR >2.6) had 47% (9–99%) larger odds of cognitive dysfunction. The associations could indicate that a significant proportion of dementia cases in women is likely to be preventable by effective prevention and control of the insulin homeostasis.

Arterial hypotension is frequent in patients undergoing anesthesia and may aggravate the outcome. Common genetic variations may influence the cardiovascular response to anesthesia. In this retrospective cohort study, we tested whether variation in the gene encoding the β2-adrenergic receptor (ADRB2) influences perioperative arterial blood pressure and consequently the use of vasopressors.Five hundred seventy-one Danish Caucasians undergoing neurosurgery were genotyped for 5 marker single-nucleotide polymorphisms (SNPs) within ADRB2 (Gly16Arg, Gln27Glu, Thr164Ile, Arg175Arg, and Gly351Gly). A pairwise tagging principle was used to identify ADRB2 haplotypes. Mean arterial blood pressure (MAP) was recorded in the supine awake state and, together with administration of vasopressors (ephedrine and/or phenylephrine), for 30 minutes after induction of general anesthesia (sevoflurane/remifentanil or propofol/remifentanil).Four hundred thirteen (72%) patients received ephedrine and/or phenylephrine. Only baseline MAP (P0.001) and the Arg175Arg SNP (P = 0.01) were associated with nadir perioperative MAP. The Gly16Arg SNP but no other SNPs showed a trend toward an association with the amount of vasopressors used during anesthesia with Arg16 homozygotes receiving less ephedrine equivalents. The Arg16-Gln27-Thr164-Arg175-Gly351 haplotype was associated with approximately 13% lower vasopressor requirements than the most common Gly16-Glu27-Thr164-Arg175-Gly351 haplotype (P = 0.01).Gly16 carriers received larger amounts of vasopressor compared with Arg16 homozygotes. This corresponds to previous studies demonstrating that the Gly16 allele in ADRB2 is associated with vasodilation and high cardiac output.

Background Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine reduces the scO2. We hypothesized that norepinephrine-induced reduction in scO2 is influenced by cutaneous vasoconstriction. Methods Fifteen healthy male subjects (25 ± 5 yr, mean ± SD) were studied during: hyperventilation (1.5 kPa end-tidal PcO2 reduction), whole-body heating, administration of norepinephrine (0.15 μg · kg · min; with and without end-tidal carbon dioxide correction), and hypoxia (FiO2: 0.12%). Arterial (saO2), skin, and internal jugular venous oxygen saturations (sjO2) were recorded, and the average cerebral capillary oxygen saturation (scapO2) was calculated. Results This study indicates that scO2 is influenced by skin oxygen saturation because whole-body heating increased scO2 by 3.6% (2.1-5.1%; 95% CI) and skin oxygen saturation by 3.1% (1.3-4.9%), whereas scapO2 remained unaffected. Conversely, hyperventilation decreased scO2 by 2.1% (0.4-3.7%) and scapO2 by 5.3% (3.8-6.9%), whereas skin oxygen saturation increased 1.8% (0.5-3.1%). In response to hypoxia, scO2 (10.2%; 6.6-13.7%), scapO2 (7.9%; 6.4-9.4%), and skin oxygen saturation (8.9%; 6.3-11.6%) all decreased. With administration of norepinephrine there was a 2.2% (1.0-4.3%) decrease in skin oxygen saturation and scO2 decreased 6.2% (4.2-8.0%), with scapO2 remaining unaffected. Conclusion The results confirm that spatially resolved near-infrared spectroscopy detects cerebral deoxygenation with systemic hypoxic exposure and hyperventilation. However, a commonly used vasopressor norepinephrine disturbs skin oxygen saturation to an extent that influences scO2.

Introduction Ultrasound guidance is increasingly used for invasive anaesthetic procedures to improve efficacy, facilitate performance and reduce risk of complications. Herein, we present a simple approach to ultrasound-guided locoregional anaesthesia for patients undergoing eversion carotid endarterectomy. Methods At the level of the base of the carotid bifurcation, the needle was inserted at the lateral border of the sternocleidomastoid muscle and, guided by ultrasound, advanced 0.5–1 cm posterolateral to the carotid artery, where ropivacaine (7.5 mg ml −1 ) was injected. During retraction of the needle, additional local anaesthetic was administered beneath the sternocleidomastoid muscle and, finally, subcutaneous infiltration along the surgical incision line was performed. The primary study end point was the amount of additional ropivacaine (7.5 mg ml −1 ) provided intra-operatively. Secondary measures included the occurrence of puncture-related complications and the adverse effects to locoregional anaesthesia. Results Sixty consecutive patients admitted for primary carotid endarterectomy were prospectively included. The volume of administered ropivacaine for locoregional anaesthesia and subsequent intra-operative supplementation was 31.7 ± 3.5 and 1.9 ± 2.5 ml, respectively. There were no conversions to general anaesthesia. Intravascular or subarachnoid injection of local anaesthetic did not occur, and symptoms of local anaesthetic systemic toxicity did not present. Related to the blockade, hoarseness (72%), Horner syndrome (37%), cough (20%), facial palsy (13%) and dysphagia (12%) were observed and resolved on the first postoperative day. Conclusions This observational study demonstrates that the described ultrasound-guided locoregional anaesthesia is suitable for eversion carotid endarterectomy and the amount of supplemental anaesthetic during the surgery is low.

Toft BG, Federspiel BH, Sorensen SS, Bagi P, Nielsen HB, Andersen CB. A histopathological score on baseline biopsies from elderly donors predicts outcome 1 year after renal transplantation. APMIS 2012; 120: 182–6. Kidneys from elderly deceased patients and otherwise marginal donors may be considered for transplantation and a pretransplantation histopathological score for prediction of postoperative outcome is warranted. In a retrospective design, 29 baseline renal needle biopsies from elderly deceased donors (age: 63 ± 4 years; mean ± SD) were evaluated independently by three pathologists and with ten or more glomeruli and one artery present the biopsy was histopathologically scored (numeric score: 0–12) according to the presence of glomerulosclerosis, tubular atrophy, interstitial fibrosis and increased wall thickness of arteries and/or arterioles. Nineteen renal baseline biopsies from 15 donors (age: 64 ± 10 years) were included and following consensus the histopathological score was 4.3 ± 2.1 (intraclass correlation coefficient: 0.81; confidence interval: 0.66–0.92). The donor organs were used for single renal transplantation (recipient age: 47 ± 3 years). Two grafts were lost after the transplantation. In the remaining 17 recipients the 1-year creatinine clearance (54 ± 6 mL/min) correlated to the baseline histopathological score (r2 = 0.59; p

Objective The intron 16 insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene has been associated with rupture of intracranial aneurysms, but the effect of haplotypes within ACE has not been studied. This study investigated whether ACE haplotypes including the I/D polymorphism are associated with aneurysmal subarachnoid hemorrhage. Methods The hypothesis was tested with a case-control design in 176 patients with aneurysmal subarachnoid hemorrhage and with 498 hospital controls. Through the pairwise tagging principle, single nucleotide polymorphisms (rs4291 A/T, rs4295 C/G, rs4305 C/T, rs4311 C/T, rs4331 T/C, rs4343 C/T) in the ACE gene were genotyped along with the I/D polymorphism. Haplotypes were estimated using the PHASE software. Results Fifty-five haplotypes were identified with 3 of these having a frequency above 5%: ACCCCIT (41.6±0.4%), TGTTTDC (32.1±0.5%), and ACCTTDC (9.5±0.2%). No significant difference in distribution of alleles, genotypes, haplotypes, or haplotype pairs between the 2 populations was found. Specifically, we could not reproduce previously reported associations between the ACE I genotype and intracranial aneurysms. When subdivided into groups of aneurysm location, we found a trend toward an association between homozygotes of the ACCCCIT haplotype and middle cerebral artery aneurysms, odds ratio=2.9 (1.0 to 7.6), which however proved insignificant (P=0.22) after correction for multiple testing. Conclusion In this Danish population, ACE haplotypes and the I/D polymorphism did not contribute significantly to the overall risk of intracranial aneurysm rupture. Larger studies are needed to delineate the association between ACE polymorphism and ruptured middle cerebral artery aneurysms.

Exercise lowers the cerebral metabolic ratio of O2 to carbohydrate (glucose+1/2 lactate) and metabolic acidosis appears to promote cerebral lactate uptake. However, the influence of pH on cerebral lactate uptake and, in turn, on the cerebral metabolic ratio during exercise is not known. Sodium bicarbonate (Bicarb, 1 M; 350-500 ml) or an equal volume of normal saline (Sal) was infused intravenously at a constant rate during a '2000 m' maximal ergometer row in six male oarsmen (23±2 years; mean±S.D.). During the Sal trial, pH decreased from 7.41±0.01 at rest to 7.02±0.02 but only to 7.36±0.02 (P

During brain activation, the decrease in the ratio between cerebral oxygen and carbohydrate uptake (6 O2/(glucose +1/2 lactate); the oxygen–carbohydrate index, OCI) is attenuated by the non-selective β-adrenergic receptor antagonist propranolol, whereas OCI remains unaffected by the β1-adrenergic receptor antagonist metroprolol. These observations suggest involvement of a β2-adrenergic mechanism in non-oxidative metabolism for the brain. Therefore, we evaluated the effect of adrenaline (0.08 μg kg−1 min−1i.v. for 15 min) and noradrenaline (0.5, 0.1 and 0.15 μg kg−1 min−1i.v. for 20 min) on the arterial to internal jugular venous concentration differences (a-v diff) of O2, glucose and lactate in healthy humans. Adrenaline (n= 10) increased the arterial concentrations of O2, glucose and lactate (P < 0.05) and also increased the a-v diff for glucose from 0.6 ± 0.1 to 0.8 ± 0.2 mm (mean ±s.d.; P < 0.05). The a-v diff for lactate shifted from a net cerebral release to an uptake and OCI was lowered from 5.1 ± 1.5 to 3.6 ± 0.4 (P < 0.05) indicating an 8-fold increase in the rate of non-oxidative carbohydrate uptake during adrenaline infusion (P < 0.01). Conversely, noradrenaline (n= 8) did not affect the OCI despite an increase in the a-v diff for glucose (P < 0.05). These results support that non-oxidative carbohydrate consumption for the brain is driven by a β2-adrenergic mechanism, giving neurons an abundant provision of energy when plasma adrenaline increases.