OBJECTIVETo examine cross-sectional associations of serum vitamin D [25-hydroxyvitamin D, 25(OH)D] concentration with insulin resistance (IR) and β-cell dysfunction in 712 subjects at risk for type 2 diabetes.RESEARCH DESIGN AND METHODSSerum 25(OH)D was determined using a chemiluminescence immunoassay. Insulin sensitivity/resistance were measured using the Matsuda insulin sensitivity index for oral glucose tolerance tests (ISOGTT) and homeostasis model assessment of insulin resistance HOMA-IR. β-Cell function was determined using both the insulinogenic index (IGI) divided by HOMA-IR (IGI/IR) and the insulin secretion sensitivity index-2 (ISSI-2).RESULTSLinear regression analyses indicated independent associations of 25(OH)D with ISOGTT and HOMA-IR (β = 0.004, P = 0.0003, and β = −0.003, P = 0.0072, respectively) and with IGI/IR and ISSI-2 (β = 0.004, P = 0.0286, and β = 0.003, P = 0.0011, respectively) after adjusting for sociodemographics, physical activity, supplement use, parathyroid hormone, and BMI.CONCLUSIONSVitamin D may play a role in the pathogenesis of type 2 diabetes, as 25(OH)D concentration was independently associated with both insulin sensitivity and β-cell function among individuals at risk of type 2 diabetes.

BACKGROUND-Despite its proven benefits and need, women are significantly less likely to participate in and complete cardiac rehabilitation (CR) than men. The purpose of this study was to quantitatively investigate sex differences in CR barriers by participation status.

Objective-To investigate the degree of CHD awareness as well as symptom, risk factor, and treatment knowledge in a broad sample of cardiac inpatients, and to examine its sociodemographic, clinical and psychosocial correlates.Methods-1308 CHD inpatients (351 [27.0%] female), recruited from 11 acute care sites in Ontario, participated in this cross-sectional study. Participants were provided with a survey which included a knowledge questionnaire among other measures, and clinical data were extracted from medical charts.Results-855 (68.8%) respondents cited heart disease as the leading cause of death in men, versus only 458 (37.0%) in women. Participants with less than high school education (p<.001), an annual family income less than $50,000CAD (p=.022), low functional capacity (p=.042), who were currently smoking (p=.022), who had no family history of heart disease (p<.001), and who had a perception of low personal control (p=.033) had significantly lower CHD knowledge. Conclusions-Awareness CIHR Author Manuscript CIHR Author Manuscript CIHR Author ManuscriptPractice implications-Tailored educational approaches may be necessary for those of low socioeconomic status, particularly with regard to the nature of CHD, tests and treatments.

Serum 25(OH)D, but not PTH, was significantly associated with MetS as well as a number of MetS components after multivariate adjustment. These results suggest that low 25(OH)D may play a role in the etiology of the MetS.

OBJECTIVEEmerging evidence suggests that peripheral neuropathy begins in the early stages of diabetes pathogenesis. Our objective was to describe the prevalence of peripheral neuropathy and nerve dysfunction according to glucose tolerance and metabolic syndrome status and examine how these conditions are associated with neurological changes in individuals at risk for type 2 diabetes. RESEARCH DESIGN AND METHODSWe studied 467 individuals in the longitudinal PROMISE (Prospective Metabolism and Islet Cell Evaluation) cohort. Peripheral neuropathy was defined by Michigan Neuropathy Screening Instrument (MNSI) scores (>2), and the severity of nerve dysfunction was measured objectively by vibration perception thresholds (VPTs) using a neurothesiometer. Metabolic syndrome was defined using the International Diabetes Federation/American Heart Association harmonized criteria. RESULTSThe prevalence of peripheral neuropathy was 29%, 49%, and 50% for normal glycemia, prediabetes, and new-onset diabetes, respectively (P < 0.001 for trend). The mean VPT was 6.5 V for normal glycemia, 7.9 V for prediabetes, and 7.6 V for new-onset diabetes (P = 0.024 for trend). Prediabetes was associated with higher MNSI scores (P = 0.01) and VPTs (P = 0.004) versus normal glycemia, independent of known risk factors. Additionally, progression of glucose intolerance over 3 years predicted a higher risk of peripheral neuropathy (P = 0.007) and nerve dysfunction (P = 0.002). Metabolic syndrome was not independently associated with MNSI scores or VPTs. CONCLUSIONSIn individuals with multiple risk factors for diabetes, prediabetes was associated with similar risks of peripheral neuropathy and severity of nerve dysfunction as new-onset diabetes. Prediabetes, but not metabolic syndrome, was independently associated with both the presence of peripheral neuropathy and the severity of nerve dysfunction.Peripheral neuropathy is a serious complication of diabetes. It plays a major contributory role in the initiation of foot ulceration and the subsequent development of lowerextremity amputation, resulting in severe disability, reduced quality of life, and a significant economic burden to the health care system (1). Peripheral neuropathy is