Abstract
INTRODUCTION: To assess vascular function and characterize insulin secretion using a physiological approach in Japanese women with family history of type 2 diabetes (FHD). RESEARCH DESIGN AND METHODS: Standardized mixed-meal tests were performed with multiple postprandial glucose, insulin and free fatty acids (FFA) measurements over a 30-120 min period in 31 Japanese women aged 21-24 years. Arterial distensibility was assessed as well. RESULTS: Fasting glucose, triglyceride and insulin averaged <90 mg/dL, <60 mg/dL and <5 μU/mL, respectively, and did not differ cross-sectionally between 10 with (FHD+) and 21 without FHD (FHD-). FHD+ showed higher insulin responses not only during the first 30 min (p=0.005) but also during the second hour (60-120 min, p<0,05) in spite of identical postprandial suppression of FFA and identical fasting and postprandial glucose and FFA concentrations, except for higher 60 min FFA in FHD+. Further, FHD+ had decreased arterial distensibility (p=0.003). On multivariate regression analysis, arterial distensibility emerged as the only significant independent predictor of FHD+. Endurance training in FHD+ did not alter decreased arterial distensibility whereas it abolished postprandial hyperinsulinemia. CONCLUSIONS: FHD was associated with decreased arterial distensibility and postprandial hyperinsulinemia despite nearly identical postprandial glycemia and postprandial FFA suppression, suggesting that impaired vascular insulin sensitivity may precede glucose and lipid dysmetabolism in normal weight Japanese women aged 22 years.