Abstract P446: Comparison of Markers Related to Insulin Resistance between US Caucasian Men and Japanese Men in Japan
Introduction: Although Asians including Japanese are more susceptible to developing type 2 diabetes (T2DM) compared to Caucasians, no previous studies have compared levels of insulin resistance between Japanese and Caucasians with the gold standard method, i.e., euglycemic glucose clamp. We have previously reported that levels of atherosclerosis are significantly lower in middle-aged men in Japan than US Caucasian after adjusting for risk factors including body-mass index (BMI). We hypothesized that Japanese men in Japan are less insulin resistant than Caucasian men and compared markers related to insulin resistance in these two groups.
Methods: Population-based samples of 623 randomly selected men aged 40-49 years (313 Japanese men from Kusatsu, Shiga Japan and 310 Caucasian men from Allegheny County, PA) without clinical CVD were examined. We excluded 31 men with T2DM. Using ANCOVA, adjusting for BMI, we evaluated the following markers related to insulin resistance in the two populations: HOMA-IR, non-esterified fatty acids (NEFA), adiponectin, HDL-C, triglycerides, CRP, plasminogen-activator inhibitor 1 (PAI-1), systolic blood pressure (BP), and other risk factors (Table).
Results: After adjusting for BMI, HOMA-IR, the most widely used marker of insulin resistance, was not statistically different between the two groups (Table). Among 19 variables compared, the results of NEFA, CRP, fibrinogen and HLD-P supported the hypothesis that Japanese are less insulin resistant. In contrast the results of adiponectin, PAI-1, triglycerides, total LDL-P, small LDL-P and systolic BP suggest that Japanese are more insulin resistant. Results of HOMA-β% and disposition index suggest that Japanese secrete less insulin than Caucasians.
Conclusion: It is inconclusive whether Japanese are less insulin resistant than Caucasians based on comparisons of markers related to insulin resistance. Our data also suggest that Japanese as compared to Caucasians may secrete less insulin at the same levels of insulin resistance.
- © 2013 by American Heart Association, Inc.