Associations between alcohol consumption and insulin sensitivity and cardiovascular disease risk factors - The insulin resistance and atherosclerosis study

OBJECTIVE - Light-to-moderate alcohol consumption has been associated with reduced cardiovascular disease (CVD) mortality, which may be explained by increased insulin sensitivity (S-I) and an improved Lipoprotein and blood pressure profile. Prior research has shown improved S-I with light-to-moderate alcohol intake even though somewhat imprecise measures of S-I were used. RESEARCH DESIGN AND METHODS - Relationships between alcohol use and S-I and CVD risk factors were assessed in a cross-sectional analysis of 1,196 white, African-American, and Hispanic men and women from the Insulin Resistance and Atherosclerosis Study (IRAS). Five categories of previous-year alcohol use (never, <0.5 drinks/day, 0.5-0.99 drinks/day, 1-2.99 drinks/day, and <greater than or equal to>3 drinks/day) and log S-I + 1 (frequently sampled intravenous glucose tolerance test with Bergman minimal model analysis), log fasting insulin, log triglycerides, HDL cholesterol, and systolic/diastolic blood pressure were examined using analysis of variance. RESULTS - Univariate analysis showed an inverse U-shaped relationship between S-I and alcohol intake, with a peak at the 0.5-0.99 drinks/day category. A W-shaped relationship was observed between fasting insulin and the lipid and blood pressure measures. After adjustment for demographic (clinic, sex, ethnicity, age), lifestyle (smoking, dietary energy/fat intake, physical activity), and physical (BMI, waist circumference) variables, the alcohol/insulin association was attenuated but the association with lipids and blood pressure remained for high-intake categories. CONCLUSIONS - These data suggest that the enhanced S-I associated with light-to-moderate alcohol consumption may be a function solely of a BMI and central adiposity profile more favorable to higher S-I.