Background: There is a great deal of controversy surrounding the relationship between alcohol consumption and insulin resistance. This association may be further confounded by the presence of obesity. We aimed to clarify whether regular alcohol consumption improves insulin resistance in healthy Japanese men and whether obesity affects this relationship.
Methods: We examined 1029 men (ages 24 to 87 y) who had undergone medical checkups. They were divided into non-obese (body mass index (BMI) <25 kg/m(2)) or obese subjects (BMI > or =25 kg/m(2)) and further classified into non-regular drinkers (NRD), moderate drinkers (MD; 1-6 days/week), and daily drinkers (DD; 7 days/week). The homeostasis model assessment of insulin resistance (HOMA-IR) and other cardiac risk factors were compared between the groups.
Results: In both non-obese and obese men, alcohol consumption decreased HOMA-IR in a dose-dependent manner, although HOMA-IR was about 2 times greater in obese men compared to non-obese men in any category (p<0.001). Stepwise logistic regression analysis revealed that alcohol consumption was the independent negative risk factor for HOMA-IR [OR, 0.576 (95% C.I. 0.402-0.824), p=0.003] after adjusting for age, BMI, systolic blood pressure, smoking status, LDL-cholesterol, HDL-cholesterol, and liver dysfunction.
Conclusions: Regular alcohol consumption improves insulin resistance in healthy Japanese men independent of obesity.