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AIMS: Our objective was to examine prospectively the associations between fasting plasma proinsulin and the proinsulin/insulin ratio and the incidence of Type 2 diabetes in women. SUBJECTS AND METHODS: We designed a nested case-control study within the Nurses' Health Study, a cohort of 121,700 US women aged 30-55 years at study inception in 1976. Fasting plasma proinsulin, specific insulin and C-peptide levels were determined in 183 women with a new diagnosis of diabetes made after blood sampling between 1989 and 1990, and 369 control subjects without diabetes. RESULTS: After adjustment for age, body mass index, family history of diabetes and other potential confounders, including HbA1c, the odds ratios for diabetes associated with increasing quartiles of proinsulin were 1.00, 0.85, 2.49 and 5.73 (P for trend: < 0.001). Proinsulin remained significantly associated with diabetes risk after adjusting for C-peptide and specific insulin (multivariate odds ratios for quartiles: 1.00, 0.78, 1.94, 3.69; P for trend = 0.001). In addition, the proinsulin/insulin ratio was significantly associated with diabetes risk, controlling in multivariate analysis for C-peptide (odds ratios for extreme quartiles: 2.48; 95% CI: 1.14-5.41; P for trend = 0.005). CONCLUSIONS: These data suggest that proinsulin and the proinsulin/insulin ratio are strong independent predictors of diabetes risk, after adjustment for obesity and other potential confounders. [ABSTRACT FROM AUTHOR]

Hemolysis is a key feature of sickle cell anemia (HbSS). Direct quantitation of hemolysis could be used as an objective outcome in clinical trials of new therapeutics for HbSS and would also enable better human studies of the pathogenesis of complications of HbSS that are ostensibly hemolysis-related, such as pulmonary hypertension. However, contemporary human studies in HbSS have used only surrogate markers of hemolysis rather than direct measurements of RBC survival. We directly quantified hemolysis in HbSS by measuring survival of an age cohort of RBCs labeled with a stable isotope, administered orally as 15 N-glycine, a metabolic precursor of heme. The atomic excess of 15 N in heme extracted from blood was monitored by mass spectrometry over time. We performed 13 labeling experiments in 11 individuals with HbSS. Mean RBC survival was 31.9 days (range 14.1-53.6). Both HbF level, a known determinant of hemolysis, and absolute reticulocyte count (ARC), an index of the marrow's response to hemolysis, correlated with directly measured RBC survival (r = 0.61, P < 0.002; r = -0.84, P < 0.001). However, commonly used biochemical surrogates of hemolysis (LDH, AST, bilirubin, and plasma free hemoglobin) did not correlate with directly measured RBC survival. These biochemical surrogates should be interpreted cautiously, at best, in clinical trials and human physiologic studies in HbSS. ARC was the best correlate of total hemolysis, but only 70% of the variation in RBC survival was reflected in this marker. If greater accuracy is required in human studies, 15 N-glycine RBC labeling can directly and accurately quantify hemolysis. Am. J. Hematol. 91:1195-1201, 2016. © 2016 Wiley Periodicals, Inc., Competing Interests: The authors have no conflicts of interest to declare., (© 2016 Wiley Periodicals, Inc.)

The aim of this study was to identify the clinical features of participants in the standard therapy arm of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) glycaemia trial who failed to reach the glycated haemoglobin (HbA1c) target. We analysed 4685 participants in the standard therapy arm, comparing participants who reached the HbA1c target of <8.0% with those whose HbA1c level was ≥8.0% 12 months after randomization. Baseline and 12-month clinical characteristics were compared. At 12 months after randomization, 3194 participants had HbA1c <8.0% and 1491 had HbA1c ≥8.0%. Black race [odds ratio (OR) 0.74, 95% confidence interval (CI) 0.61-0.89; p = 0.002], severe hypoglycaemia (OR 0.57, CI 0.37-0.89; p = 0.014) and insulin use (OR 0.51, CI 0.40-0.65; p < 0.001) were associated with failure to reach HbA1c goal at 12 months in the adjusted model. Even with free medications, free visits with clinicians and aggressive titration of medications, >30% of participants in the standard arm of the ACCORD trial had an HbA1c ≥8.0% at 1 year. Participants who were black, had severe hypoglycaemia and were on insulin were more likely to have an above-target HbA1c concentration after 12 months on the standard protocol., (© 2015 John Wiley & Sons Ltd.)

HbA1c is commonly used to monitor glycemic control. However, there is growing evidence that the relationship between HbA1c and mean blood glucose (MBG) is influenced by variation in red blood cell (RBC) lifespan in hematologically normal individuals. Correction of HbA1c for mean RBC age (MRBC ) requires a noninvasive, accurate, and affordable method to measure RBC survival. In this study, we evaluated whether a stable isotope approach would satisfy these requirements. RBC lifespan and MRBC were determined in a group of nine hematologically normal diabetic and nondiabetic subjects using oral (15) N-glycine to label heme in an age cohort of RBC. The MRBC was 58.7 ± 9.1 (2SD) days and RBC lifespan was 106 ± 21 (2SD) days. This degree of variation (±15-20%) is consistent with previous studies using other techniques. In a subset of seven subjects, MRBC determined with the biotin label technique were available from approximately five years prior, and strongly correlated with the stable isotope values (R(2) = 0.79). This study suggests that the MRBC is stable over time but varies substantially among individuals, and supports the importance of its variation in HbA1c interpretation. The characteristics of the stable isotope method support its suitability for studies to directly evaluate the impact of variation in MRBC on the interpretation of HbA1c., (© 2014 Wiley Periodicals, Inc.)

Objective: This study examines the impact of major depressive disorder (MDD) and its treatment on quality of life (QOL)., Method: From the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial, we analyzed complete data of 2280 adult MDD out-patients at entry/exit of each level of antidepressant treatments and after 12 months of entry to follow-up. QOL was measured using the QOL Enjoyment and Satisfaction Questionnaire (Q-LES-Q). The proportions of patients scoring 'within-normal' QOL (within 10% of Q-LES-Q community norms) and those with 'severely impaired' QOL (>2 SD below Q-LES-Q community norms) were analyzed., Results: Before treatment, no more than 3% of MDD patients experienced 'within-normal' QOL. Following treatment, statistically significant improvements were detected; however, the proportion of patients achieving 'within-normal' QOL did not exceed 30%, with >50% of patients experiencing 'severely impaired' QOL. Although remitted patients had greater improvements compared with non-remitters, 32-60% continued to experience reduced QOL. 12-month follow-up data revealed that the proportion of patients experiencing 'within-normal' QOL show a statistically significant decrease in non-remitters., Conclusion: Symptom-focused treatments of MDD may leave a misleading impression that patients have recovered when, in fact, they may be experiencing ongoing QOL deficits. These findings point to the need for investigating specific interventions to ameliorate QOL in MDD., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The changes in red blood cells (RBC) as they age and the mechanisms for their eventual removal have been of interest for many years. Proposed age-related changes include dehydration with increased density and decreased size, increased membrane IgG, loss of membrane phospholipid asymmetry, and decreased activity of KCl cotransport. The biotin RBC label allows unambiguous identification of older cells and exploration of their properties as they age. Autologous normal human RBC were labeled ex vivo and, after reinfusion, compared with unlabeled RBC throughout their lifespan. RBC density increased with age, with most of the change in the first weeks. Near the end of their lifespan, RBC had increased surface IgG. However, there was no evidence for elevated external phosphatidylserine (PS) even though older RBC had significantly lower activity of aminophospholipid translocase (APLT). KCl cotransport activity persisted well past the reticulocyte stage, but eventually decreased as the RBC became older. These studies place limitations on the use of density fractionation for the study of older human RBC, and do not support loss of phospholipid asymmetry as a mechanism for human RBC senescence. However, increased levels of IgG were associated with older RBC, and may contribute to their removal from the circulation., (Copyright © 2012 Wiley Periodicals, Inc.)

New methods for labeling red blood cells (RBC) and monitoring their survival have made it possible to explore changes in the properties of RBC as they age in the circulation. We have adapted a method, originally developed for studying wild animals, to calculate the age of a random sample of labeled RBC from their survival curve. We also show how this method can be expanded to allow continuous calculation of the mean age of the labeled RBC population at any time after labeling. It is expected that this analytical approach will be useful in the study of age-dependent RBC changes., (Copyright 2008 Wiley-Liss, Inc.)

Regional cerebral glucose metabolism was measured in a 72-year-old man, with Creutzfeldt-Jakob disease (CJD), by positron emission tomography using [18F]-2-fluoro-2-deoxy-D-glucose as the tracer. The diagnosis of CJD, a rare neurodegenerative disorder, was confirmed at autopsy 13 months later. Compared with five unaffected elderly men, the patient had reduced metabolism heterogeneously distributed throughout the brain. The hypometabolism was most evident in the right hemisphere, particularly in the posterior frontal, parietal, Sylvian, and temporal regions. This left-right asymmetry is more extensive than that previously reported in Alzheimer's disease, and may provide a useful metabolic marker for early diagnosis of CJD.