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We assessed the prescription patterns of oral antidiabetic drugs in Japanese patients with type 2 diabetes between 2002 and 2020 using data from the Computerized Diabetes Care database. Among 172,960 patients treated with oral antidiabetic drugs, both the sulfonylurea prescription rate and dose decreased from 2002 to 2020. Prescriptions of biguanides, dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter 2 inhibitors increased; their dose and dose frequency remained relatively stable. Trends in oral antidiabetic drug prescriptions changed over time, reflecting guideline recommendations and existing evidence.

Insights from epidemiological, clinical and basic research are illuminating the interplay between metabolic disorders, cardiovascular disease (CVD) and kidney dysfunction, termed cardio-renal-metabolic (CRM) disease. Broadly defined, CRM disease involves multidirectional interactions between metabolic diseases such as type 2 diabetes (T2D), various types of CVD and chronic kidney disease (CKD). T2D confers increased risk for heart failure, which-although well known-has only recently come into focus for treatment, and may differ by ethnicity, whereas atherosclerotic heart disease is a well-established complication of T2D. Many people with T2D also have CKD, with a higher risk in Asians than their Western counterparts. Furthermore, CVD increases the risk of CKD and vice versa, with heart failure, notably, present in approximately half of CKD patients. Molecular mechanisms involved in CRM disease include hyperglycaemia, insulin resistance, hyperactivity of the renin-angiotensin-aldosterone system, production of advanced glycation end-products, oxidative stress, lipotoxicity, endoplasmic reticulum stress, calcium-handling abnormalities, mitochondrial malfunction and deficient energy production, and chronic inflammation. Pathophysiological manifestations of these processes include diabetic cardiomyopathy, vascular endothelial dysfunction, cardiac and renal fibrosis, glomerular hyperfiltration, renal hypoperfusion and venous congestion, reduced exercise tolerance leading to metabolic dysfunction, and calcification of atherosclerotic plaque. Importantly, recognition of the interaction between CRM diseases would enable a more holistic approach to CRM care, rather than isolated treatment of individual conditions, which may improve patient outcomes. Finally, aspects of CRM diseases may differ between Western and East Asian countries such as Japan, a super-ageing country, with potential differences in epidemiology, complications and prognosis that represent an important avenue for future research.

Accumulating evidence suggests health benefits of ketone bodies, and especially for longevity. However, the precise role of endogenous ketogenesis in mammalian life span, and the safety and efficacy of the long-term exogenous supplementation of ketone bodies remain unclear. In the present study, we show that a deficiency in endogenous ketogenesis, induced by whole-body Hmgcs2 deletion, shortens life span in mice, and that this is prevented by daily ketone body supplementation using a diet containing 1,3-butanediol, a precursor of β-hydroxybutyrate. Furthermore, feeding the 1,3-butanediol-containing diet from early in life increases midlife mortality in normal mice, but in aged mice it extends life span and prevents the high mortality associated with atherosclerosis in ApoE-deficient mice. By contrast, an ad libitum low-carbohydrate ketogenic diet markedly increases mortality. In conclusion, endogenous ketogenesis affects mammalian survival, and ketone body supplementation may represent a double-edged sword with respect to survival, depending on the method of administration and health status.

Recent major clinical trials of the use of sodium–glucose cotransporter 2 (SGLT2) inhibitors in patients with type 2 diabetes have shown that they reduce three‐point major adverse cardiovascular events, cardiovascular death, hospitalization for heart failure (HF) and a composite renal outcome. These beneficial effects of SGLT2 inhibitors are also evident in type 2 diabetes patients with a previous history of atherosclerotic cardiovascular disease or advanced renal disease. HF is a major determinant of the prognosis of diabetes patients. Although HF with low ejection fraction can be effectively treated with antihypertensive drugs, these treatments do not reduce mortality in HF patients with preserved ejection fraction (HFpEF). HFpEF is clinically characterized by left ventricular diastolic dysfunction, perivascular fibrosis and stiffness of cardiomyocytes, defined as “cardiomyopathy”. Therefore, HFpEF is considered to be an entirely separate entity to HF with low ejection fraction. Recent studies have suggested that HFpEF might be treatable using SGLT2 inhibitors, which ameliorate visceral adiposity, insulin resistance, hyperglycemia, hyperlipidemia, volume overload, hypertension and cardiac inflammation. In the final part of the present review, we discuss the biochemical and molecular mechanisms of the effects of SGLT2 inhibitors in type 2 diabetes patients with HFpEF. These involve amelioration of the low nitric oxide production and oxidative stress, a reduction in cardiac inflammatory cytokine signaling, inhibition of Ca2+ overload, and an improvement in cardiac energy metabolism as a result of ketone body production. Investigations of the beneficial effects of SGLT2 inhibitors on cardiorenal outcomes, including hospitalization for HF, are now being carried out in preclinical and clinical studies., Heart failure is a major determinant of life prognosis in diabetes patients. Two potential mechanisms for the progression of heart failure in diabetes are reviewed – the development of heart failure with preserved ejection fraction and heart failure with low ejection fraction. Sodium–glucose cotransporter 2 inhibitors can protect progression of heart failure with preserved ejection fraction in diabetes patients by improving multiple metabolic and hemodynamic derangements, as well as by improving endothelial dysfunction, oxidative stress, pro‐inflammatory cytokine signaling, Ca++ overloading and metabolic crisis in cardiomyocytes in diabetes.

Aims/Introduction Preprandial metformin administration significantly reduces postprandial plasma triglyceride levels in animal studies by reducing intestinal absorption through delayed gastric emptying. However, this effect has not been shown in a clinical study. Therefore, we planned to investigate the efficacy of preprandial metformin administration on postprandial hypertriglyceridemia and the related gastrointestinal effects in patients with type 2 diabetes mellitus. Materials and Methods A total of 11 patients taking single‐dose metformin at 500–1,000 mg, with non‐fasting plasma triglyceride levels of 150–1,000 mg/dL, were recruited at a single university hospital. The difference between preprandial and postprandial metformin administration on postprandial hypertriglyceridemia was examined by a meal test. The gastrointestinal effects of metformin, including stomach heaviness, heartburn and satiety, were also assessed using a visual analog scale. Results The mean bodyweight of patients was 80.6 kg (body mass index 27.9 kg/m2), and the mean non‐fasting plasma triglyceride level was 275.9 ± 57.0 mg/dL. The area under the curve of triglyceride during the meal test was significantly lower in the preprandial protocol than in the postprandial protocol (P

Aims To investigate the effects of sodium‐glucose co‐transporter‐2 (SGLT2) inhibitors vs. dipeptidyl peptidase‐4 (DPP‐4) inhibitors on renal function preservation (RFP) using real‐world data of patients with type 2 diabetes in Japan, and to identify which subgroups of patients obtained greater RFP benefits with SGLT2 inhibitors vs. DPP‐4 inhibitors. Methods We retrospectively analysed claims data recorded in the Medical Data Vision database in Japan of patients with type 2 diabetes (aged ≥18 years) prescribed any SGLT2 inhibitor or any DPP‐4 inhibitor between May 2014 and September 2016 (identification period), in whom estimated glomerular filtration rate (eGFR) was measured at least twice (baseline, up to 6 months before the index date; follow‐up, 9 to 15 months after the index date) with continuous treatment until the follow‐up eGFR. The endpoint was the percentage of patients with RFP, defined as no change or an increase in eGFR from baseline to follow‐up. A proprietary supervised learning algorithm (Q‐Finder; Quinten, Paris, France) was used to identify the profiles of patients with an additional RFP benefit of SGLT2 inhibitors vs. DPP‐4 inhibitors. Results Data were available for 990 patients prescribed SGLT2 inhibitors and 4257 prescribed DPP‐4 inhibitors. The proportion of patients with RFP was significantly greater in the SGLT2 inhibitor group (odds ratio 1.27; P = 0.01). The Q‐Finder algorithm identified four clinically relevant subgroups showing superior RFP with SGLT2 inhibitors (P

Aims/Introduction Diabetic kidney disease is characterized by increased albuminuria and/or a reduced glomerular filtration rate (GFR). We analyzed secular changes in the prevalence of albuminuria and reduced estimated GFR (eGFR) in Japanese patients with type 2 diabetes, and identified factors associated with these changes. Materials and Methods Using 1996, 2001, 2006 and 2014 cohort data from the Japanese serial cross‐sectional studies conducted at Shiga University of Medical Science, secular changes in the prevalence of diabetic kidney disease (albuminuria and/or reduced eGFR), patient characteristics and their associations were analyzed. Results The prevalence of microalbuminuria and macroalbuminuria decreased over time, whereas the prevalence of moderately reduced eGFR (30–60 mL/min/1.73 m2) and severely reduced eGFR (

The aim of this study was to evaluate the efficacy and safety of pemafibrate in people with type 2 diabetes and hypertriglyceridaemia over a 52-week period. Participants were randomly assigned to receive treatment with placebo or pemafibrate at a dose of 0.2 or 0.4 mg/d for 24 weeks (treatment period 1). The main results from treatment period 1 have been reported previously. The assigned treatment was continued up to week 52, except that the placebo was changed to pemafibrate 0.2 mg/d after week 24 (treatment period 2). The percentage changes in fasting serum triglyceride (TG) levels at week 52 (last observation carried forward) were -48.2%, -42.3%, and -46.4% in the placebo/pemafibrate 0.2 mg/d (n = 57), pemafibrate 0.2 mg/d (n = 54), and pemafibrate 0.4 mg/d (n = 55) groups, respectively. Levels of TG, non-HDL cholesterol and total cholesterol stably decreased, whereas levels of HDL cholesterol increased with pemafibrate treatments over 52 weeks. Pemafibrate was well tolerated throughout the study period. The present study is the first to show that pemafibrate treatment substantially ameliorated lipid abnormalities and was well tolerated for 52 weeks in people with type 2 diabetes and hypertriglyceridaemia.

Aims/Introduction Specified Drug Use Results Survey of Ipragliflozin Treatment in Type 2 Diabetic Patients: Long‐term Use is an ongoing postmarketing study of ipragliflozin for long‐term use in Japanese patients with type 2 diabetes mellitus. A subgroup analysis of data from the study was carried out to investigate the impact of obesity on the efficacy and safety of ipragliflozin in this population. Materials and Methods Patients were divided into the following subgroups according to their body mass index (BMI)

Recent studies using genetically manipulated mouse models have shown the pivotal role of O‐linked N‐acetylglucosamine modification (O‐GlcNAcylation) in the metabolism of multiple organs. The molecular mechanism involves the sensing of glucose flux by the hexosamine biosynthesis pathway, which leads to the adjustment of cellular metabolism to protect against changes in the environment of each organ through O‐GlcNAcylation. More recently, not only glucose, but also fluxes of amino acids and fatty acids have been reported to induce O‐GlcNAcylation, affecting multiple cellular processes. In this review, we discuss how O‐GlcNAcylation maintains homeostasis in organs that are affected by diabetes mellitus: skeletal muscle, adipose tissue, liver and pancreatic β‐cells. Furthermore, we discuss the importance of O‐GlcNAcylation in the pathogenesis of diabetic complications. By elucidating the molecular mechanisms whereby cellular homeostasis is maintained, despite changes in metabolic flux, these studies might provide new targets for the treatment and prevention of diabetes and its complications., This article briefly reviews recent studies related with role of O‐linked N‐acetylglucosamine modification in specific organs in diabetes and its complications.

Aim/Introduction Diabetes and obesity are important health and economic concerns. We investigated the influence of obesity on diabetes control, the annual medical expenditures, and medications in Japanese patients with type 2 diabetes who were relatively lean in comparison to those in Western countries. Materials and Methods A total of 402 Japanese patients with type 2 diabetes were enrolled and their annual medical expenditures investigated. Obesity was defined as body mass index over 25 kg/m2, according to the obesity classifications from the Japan Society for the Study of Obesity. Results A total of 165 patients (41.0%) were classified as obese. The obese group was younger, had poor glycemic control, and higher frequency of hypertension than the non-obese group. The median total annual medical expenditures for all participants was 269,333 Japanese yen (interquartile: 169,664 to 437,437 Japanese yen), which was equivalent to approximately 2,450 US dollars. The annual medical expenditure was significantly higher in patients with obesity than in non-obese patients (P

Aims/Introduction To investigate the current status of achieved blood pressure levels in association with the number of antihypertensive drug classes as of 2013, and to explore the clinical correlates with achievement of target blood pressure in a large-scale cohort of Japanese individuals with type 2 diabetes. Materials and Methods A nationwide survey was carried out including 12,811 individuals with type 2 diabetes. Participants were divided by achieved blood pressure

The specific sodium–glucose cotransporter 2 inhibitors (SGLT2 inhibitors) inhibit glucose reabsorption in proximal renal tubular cells, and both fasting and postprandial glucose significantly decrease because of urinary glucose loss. As a result, pancreatic β‐cell function and peripheral insulin action significantly improve with relief from glucose toxicity. Furthermore, whole‐body energy metabolism changes to relative glucose deficiency and triggers increased lipolysis in fat cells, and fatty acid oxidation and then ketone body production in the liver during treatment with SGLT2 inhibitors. In addition, SGLT2 inhibitors have profound hemodynamic effects including diuresis, dehydration, weight loss and lowering blood pressure. The most recent findings on SGLT2 inhibitors come from results of the Empagliflozin, Cardiovascular Outcomes and Mortality in Type 2 Diabetes trial. SGLT2 inhibitors exert extremely unique and cardio‐renal protection through metabolic and hemodynamic effects, with long‐term durability on the reduction of blood glucose, bodyweight and blood pressure. Although a site of action of SGLT2 inhibitors is highly specific to inhibit renal glucose reabsorption, whole‐body energy metabolism, and hemodynamic and renal functions are profoundly modulated during the treatment of SGLT2 inhibitors. Previous studies suggest multifactorial clinical benefits and safety concerns of SGLT2 inhibitors. Although ambivalent clinical results of this drug are still under active discussion, the present review summarizes promising recent evidence on the cardio‐renal and metabolic benefits of SGLT2 inhibitors in the treatment of type 2 diabetes.

Objective The aim of this study was to search for novel markers of visceral adiposity. Methods Visceral (omental) and subcutaneous adipose tissues were obtained from 43 Japanese men. Microarray analysis using total RNA from visceral and subcutaneous adipose tissues obtained from five men with abdominal obesity and five nonobese men was first conducted. Then the expression pattern of candidate genes identified in the human study in mouse models of adiposity was examined. Results Among 30,500 genes evaluated, the mRNA expression of CCDC3 (encoding coiled-coil domain-containing protein 3) was upregulated in omental adipose tissues from abdominally obese subjects (3.07-fold) but not in subcutaneous adipose tissues (0.89-fold). Similar expression patterns were found in two distinct mouse models of obesity. In the analysis of all 43 men, CCDC3 mRNA levels in omental, but not in subcutaneous adipose tissue, were positively correlated with waist circumference and body mass index. CCDC3 was predicted to be a secretory protein, which was confirmed by western blotting, as overexpressed CCDC3 was secreted into the culture media. Conclusions The expression of CCDC3 is specifically increased in visceral adipose tissues in abdominally obese subjects. These results suggest that CCDC3 is a potential biomarker for estimating visceral adiposity.

Glycated albumin (GA) is considered a more reliable marker than glycated hemoglobin (HbA1c) for monitoring glycemic control, particularly in diabetic hemodialysis patients. We investigated the associations of GA, HbA1c, and random serum glucose levels with survival, and evaluated possible targets for improving survival in diabetic hemodialysis patients. In this prospective, longitudinal, observational study, we enrolled 90 diabetic hemodialysis patients across six dialysis centers in Japan. The median duration of follow-up was 36.0 months (mean follow-up, 29.8 months; range, 3-36 months). There were 11 deaths during the observation period. GA was a significant predictor for mortality (hazard ratio, 1.143 per 1% increase in GA; 95% confidence interval, 1.011-1.292; P = 0.033), whereas HbA1c and random glucose levels were not predictors for mortality. Receiver operating characteristics curve analysis showed that the cutoff value of GA for predicting the risk of mortality was 25%. In the Kaplan-Meier analysis, the cumulative survival rate was significantly greater in patients with GA ≤ 25% than in patients with GA >25%. GA predicted the risk of all-cause and cardiovascular mortality in diabetic hemodialysis patients. Our results suggest that GA ≤ 25% is an appropriate target for improving survival in diabetic hemodialysis patients.

Aims/Introduction To realize the effectiveness of a novel system for measuring glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET), outpatients undergoing oral glucose tolerance tests (OGTT) were investigated for the efficacy of screening for glucose intolerance using this system. Materials and Methods Fifty outpatients scheduled to undergo a 75-g OGTT for medical reasons were recruited to the study. An area of skin on the forearm was pretreated with microneedle arrays before the application of hydrogels for interstitial fluid extraction. Plasma glucose (PG) levels were measured every 30 min for 2 h to calculate reference (actual) AUC. The AUC was predicted by MIET on the basis of glucose extracted by the hydrogel using sodium ion levels as the internal standard. Results Good correlation between MIET-predicted and reference AUCs obtained using PG levels was confirmed for a wide AUC range. By introducing a threshold level for AUC to separate glucose intolerance with peak glucose ≥180 mg/dL from normal glucose tolerance, the system was demonstrated to provide better screening accuracy compared with conventional methods that use HbA1c and fasting PG levels. The results of a questionnaire-based survey administered to the subjects suggested that this system was readily accepted by the majority as a painless monitoring method. Conclusions The findings suggest that our glucose AUC measurement system using MIET would be useful for screening of glucose intolerance. In the future, this system may prove to be a useful aid as a screen for glucose intolerance before performing an OGTT for diagnosis.

Aim: Diabetic nephropathy is a serious complication in patients with type 2 diabetes. The aim of this study was to explore the factors associated with the progression of this complication in elderly patients with type 2 diabetes. Methods: This retrospective study of a subgroup of patients registered with the Japanese Elderly Diabetes Intervention Trial included 621 Japanese patients with type 2 diabetes mellitus (age ≥65 years, 346 with normoalbuminuria, 190 with microalbuminuria and 85 with overt proteinuria). Multivariate Cox proportional hazard regression model with a backward stepwise procedure was applied to select factors with significant effects on worsening of nephropathy stage and the doubling of serum creatinine. Results: During the follow up (median 52 months), 21% of patients progressed from normoalbuminuria and microalbuminuria to a worse nephropathy stage. Aging, female sex and high-density lipoprotein cholesterol were identified as independent and significant factors that worsen nephropathy stage. Also, 6.1% of patients showed doubling of serum creatinine during follow up. A positive history of cardiovascular disease, hyperuricemia and conventional therapy were identified as significant factors involved in the doubling of serum creatinine. The cumulative incidence of the doubling of serum creatinine was significantly lower in the intensive therapy group than the conventional therapy group (P = 0.016), although that of progression of nephropathy stage was similar in the two groups. Conclusions: We identified several factors associated with the progression of diabetic nephropathy in elderly patients with type 2 diabetes. The results suggest that multiple risk factor intervention seems important in preventing deterioration of renal dysfunction. Geriatr Gerontol Int 2012; 12 (Suppl. 1): 127–133.

Aims/Introduction: Activation of the renin-angiotensin system (RAS) in the kidney plays an important role in renal function. The aim of this study was to investigate whether plasma and urinary angiotensinogen levels were associated with renal and cardiovascular prognosis in type 2 diabetic patients. Materials and Methods: We measured plasma and urinary angiotensinogen levels in the observational follow-up cohort of 234 Japanese type 2 diabetic patients (144 with normoalbuminuria, 90 with albuminuria) enrolled between 1998 and 1999 and followed them up until the end of 2008. The associations of these markers with the annual decline in the estimated glomerular filtration rate (eGFR) and incidence of renal and cardiovascular composite endpoints (chronic hemodialysis, myocardial infarction, angina pectoris, stroke and cerebral hemorrhage) were evaluated. Results: At baseline, urinary angiotensinogen levels correlated with urinary albumin-creatinine ratio, urinary β2-microglobulin and inversely with eGFR. In contrast, plasma angiotensinogen levels correlated neither with these renal factors nor with urinary angiotensinogen levels. In the follow-up study (median duration: 9 years), urinary angiotensinogen, but not plasma angiotensinogen, correlated inversely with the annual change in eGFR (r = −0.51, P

Anti-diabetic agent-related hypoglycemia is a serious complication in type 2 diabetic patients on hemodialysis. Therefore, we assessed the efficacy and tolerability of 24 weeks of monotherapy with vildagliptin, a dipeptidyl peptidase four inhibitor, which is a new class of antidiabetic agent. This open-label, single-arm clinical trial was performed on 26 patients on hemodialysis. The primary assessments were changes in postprandial glucose level and glycated albumin (GA). During the study, three patients dropped out, and data from 23 patients were analyzed. Significant reductions were seen in postprandial glucose (−2.60 ± 3.80 mmol/L, P

Aims/Introduction: Although increases in urinary protein excretion generally precede a decline in the glomerular filtration rate, non-proteinuric renal impairment is common in patients with diabetes. In the present study, we examined the relationship between indices of arterial stiffness and renal function in type 2 diabetic patients without proteinuria. Methods: Blood sampling, 24-h urine collection, brachial–ankle pulse wave velocity, and 24-h ambulatory blood pressure monitoring were performed in type 2 diabetic patients without overt proteinuria. The ambulatory arterial stiffness index was calculated as (1 – the regression slope of diastolic/systolic ambulatory blood pressure). Estimated glomerular filtration rate (eGFR)was calculated using the simplified prediction equation proposed by the Japanese Society of Nephrology. Results: Of 213 non-proteinuric patients with type 2 diabetes, 60 (28.2%) had a reduced eGFR (

Aims/Introduction: Platelet-derived microparticles (PDMP) are released from the platelets either after activation or in response to physical stimulation in vivo. The present study examined the association between blood pressure and PDMP, and the effects of high-dose angiotensin receptor blockers (ARB) on PDMP in patients with type 2 diabetes. Materials and Methods: The study subjects consisted of 28 type 2 diabetes patients with blood pressure ≥130/80 mmHg who were treated with valsartan (80 mg daily). The patients were randomly assigned to take either 80 mg of telmisartan (Tel group) or 160 mg of valsartan (Val group) and then were followed up for 24 weeks. Thereafter, the patients were switched to combination therapy (5 mg of amlodipine with 40 mg of telmisartan [Tel group] or 80 mg of valsartan [Val group]) for 12 weeks. Results: Although the ambulatory blood pressure did not change, the PDMP levels were significantly decreased from baseline to week 24 (high dose ARB). In contrast, combination therapy reduced both blood pressure and PDMP levels compared with the baseline. Although the PDMP level was significantly correlated with the morning BP elevation at baseline and week 36 (combination therapy), this same relationship was not found at week 24. There were no significant differences in the blood pressure and PDMP levels between the two groups. Conclusions: Patients with morning hypertension might be at risk for cardiovascular diseases. High-dose renin-angiotensin system inhibition and blood pressure control are both considered to reduce cardiovascular events in patients with type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00048.x, 2010)

To determine the potential role of the transcriptional factor-activating enhancer-binding protein-2beta (TFAP2B) in the regulation of expression of adipokines, adiponectin, leptin, and interleukin-6 (IL-6) in vivo, we quantified the mRNA expression levels of these adipokines and TFAP2B in visceral (omental) and abdominal subcutaneous adipose tissues of 66 individuals with variable degree of adiposity and studied their correlations with BMI and their plasma concentrations. We found that BMI correlated negatively with plasma adiponectin levels and positively with those of leptin. Adiponection mRNA expression in subcutaneous fat correlated negatively with BMI, whereas leptin mRNA levels in the omentum correlated with plasma leptin levels and BMI. In contrast, IL-6 mRNA levels in subcutaneous and omental fat did not correlate with BMI. IL-6 mRNA levels in the omental fat correlated with plasma IL-6 levels. Whereas TFAP2B mRNA expression did not correlate with BMI, it correlated negatively with adiponectin expression in the subcutaneous adipose tissue. Furthermore, TFAP2B mRNA expression correlated negatively with leptin and positively with IL-6 expression in both subcutaneous and omental adipose tissues. These relationships are consistent with our in vitro observations and indicate that TFAP2B seems to regulate the expression of various adipokines in vivo.

Adiponectin is reduced in obesity, and has been suggested to play an important role in modulation of atherosclerosis. We studied the relationship between visceral (VAT) and subcutaneous (SAT) adipose tissue and serum adiponectin concentrations in Japanese men. Participants were 304 randomly selected community-based Japanese men aged 40 to 49 without a prior history of cardiovascular disease. Participants were grouped according to tertiles of serum adiponectin. In multiple linear regression analysis including age, pack years of smoking, and alcohol intake as covariates, log-transformed adiponectin was inversely associated with both VAT and SAT when these two obesity measures were included separately in the models. However, log-transformed adiponectin was inversely associated with VAT (standardized β estimate= −0.465, P< 0.0001) and positively associated with SAT (standardized β estimate = 0.166, P=0.03), when these were included concomitantly in the model. In conclusion, VAT and SAT had differential associations with serum adiponectin concentrations.

Background Higher arterial stiffness and greater peripheral vascular resistance reduce blood flow in lower-leg arteries and contribute to the development of ischaemic limb in diabetic patients even without peripheral artery occlusive disease. The aim of this study was to clarify whether these vascular parameters are associated with long-term hyperglycaemia in diabetic patients. Methods We examined 45 type 2 diabetic patients and 38 age-matched nondiabetic subjects without peripheral artery occlusive disease assessed by ankle-brachial index consecutively admitted to our hospital, and followed them over a 3-year period (3.7 ± 0.7 years) with no vasodilative medication. Blood flow and resistive index, a measure of peripheral vascular resistance, at the popliteal artery were evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Brachial-ankle pulse wave velocity was measured to assess arterial stiffness. Results At baseline, consistent with our previous report, diabetic patients showed higher brachial-ankle pulse wave velocity (p < 0.0001) and resistive index (p < 0.0001) and lower flow volume (p = 0.0044) than those of nondiabetic subjects. Stepwise multiple regression analysis revealed that duration of diabetes, mean HbA1c during the study, use of renin-angiotensin system inhibitors and change per year in resistive index were identified as significant independent variables predicting change per year in blood flow (r2 = 0.733, p < 0.0001) in diabetic patients. Mean HbA1c during the study was positively correlated with changes per year in brachial-ankle pulse wave velocity (p = 0.00007) and resistive index (p = 0.0014) and was negatively correlated with that in blood flow (p < 0.0001) in diabetic patients. Conclusions Long-term hyperglycaemia is a major cause of impaired peripheral circulation in lower-leg arteries in diabetic patients without peripheral artery occlusive disease. Copyright © 2009 John Wiley & Sons, Ltd.

A new potentiator of insulin action, 5-[4-(1-methylcyclohexylmethoxy)-benzyl]thiazolidine-2,4-dione, was tested for activation of insulin action in vitro. The agent (50 mg.kg−1.day−1) was orally administered to rats for 14 days and adipocytes from treated rats were used to assess insulin-binding, glucose uptake and glucose oxidation. In obese rats, the agent increased glucose uptake and oxidation without any change in insulin binding, whereas in lean or streptozotocin-treated rats it failed to increase glucose metabolism. Fat tissues were cultured with the agent for 24 h and were tested for insulin action. In the presence of insulin (10 ng/ml) in the culture media, the agent increased glucose oxidation in these cells without any change in insulin binding. However, without insulin in the culture media the agent did not increase glucose oxidation. Thus, the agent appeared to potentiate insulin action at the post receptor process.