Predictors of Clinical Measures of Insulin Resistance: 3542 Board #230 June 1 9:30 AM - 11:00 AM

Approximately 30.3 million adults in the United States have diabetes. Diabetic complications include stroke, myocardial infarction, nerve damage, and renal failure, among others. In addition to being the seventh leading cause of death in the country, the medical costs due to diabetes is over $325 billion annually. Clinical evaluation for type II diabetes can be assessed in a variety of ways: fasting blood glucose (FBG), hemoglobin A1c (HbA1c) percentage, and the homeostatic model assessment of insulin resistance (HOMA-IR). The PURPOSE: of this study was to evaluate the relationships between these clinical indicators and body composition, physical activity level, and glucose response to mixed nutrient challenge in older adults. METHODS: In 38 subjects (7 m /31 f) body composition (bioelectrical impedance); blood glucose (glucometer); insulin (enzyme-linked immunosorbent assay); and HbA1c (HbA1c Analyzer) were assessed. In a subset of 30 subjects, physical activity was assessed via accelerometry (Actical). Further, in a subset of 16 subjects, glucose area under the curve (gAUC) was calculated following mixed nutrient challenge (0.5 g dextrose/kg lean mass + 0.3 g protein/kg lean mass). Partial correlations (controlling for age and sex) were utilized to examine associations. Significance was set as p<0.05. RESULTS: Subject characteristics included: age= 67.9±6.6y, BMI= 29.3± 7.5 kg/m2, FBG=104.0 ±19.0 mg/dL, HOMA-IR= 2.61±1.95, and HbA1c= 5.42±0.25%. FBG was significantly correlated with body mass (r= 0.62), body fat percentage (r= 0.33); and gAUC (r= 0.59). HOMA-IR was significantly correlated with body mass (r= 0.64) and body fat percentage (r= 0.51). HbA1c was significantly correlated with gAUC (r= 0.83). There was a trend for a correlation between HbA1c and habitual, daily moderate-to-vigorous intensity physical activity (r= -0.36, p= 0.06). CONCLUSION: These preliminary data support previous findings that clinical indices of insulin sensitivity are associated with body composition. Interestingly, our data show blood glucose response to mixed nutrient intake, but not FBG, is predictive of HbA1c.