ALCOHOL-CONSUMPTION AND INSULIN CONCENTRATIONS - ROLE OF INSULIN IN ASSOCIATIONS OF ALCOHOL INTAKE WITH HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL AND TRIGLYCERIDES

Background. The relation between alcohol intake and insulin levels may explain, in part, the reported associations of alcohol with cardiovas cular disease risk factors, including high-density lipoprotein (HDL) c holesterol, triglycerides, blood pressure, and glucose levels, each of which has been recognized as a component of the insulin resistance sy ndrome. Methods and Results. Subjects included nondiabetic participant s of the Kaiser Permanente Women Twins Study (1989 through 1990). Usua l alcohol intake was assessed as part of a food frequency questionnair e. For women from twin pairs in which both twins drank (n=338), an inc rement of 12 g of alcohol per day (about one drink) was associated wit h an 8% lower 2-hour post-glucose-load insulin (P<.01) in a multiple r egression analysis for twin data, adjusted for age, body mass index, w aist-to-hip ratio, total caloric intake, and family history of diabete s. With genetic influences removed by matched analysis of the subset o f 98 monozygotic twin pairs, an intrapair.difference of 12 g of alcoho l per day was associated with a 12.4% intrapair decrement in postload insulin (P<.01). Inverse associations were also seen for fasting insul in. Alcohol consumption was inversely associated with postload glucose but not with fasting glucose in unmatched (P=.05) and matched (P=.005 ) analyses. A significant positive association of alcohol intake with high-density lipoprotein cholesterol and an inverse relation of alcoho l intake with triglycerides were each independent of insulin levels (P less-than-or-equal-to .02 in the matched models). Neither systolic no r diastolic blood pressures were related to alcohol consumption in thi s sample, perhaps because of the rather low level of alcohol intake in the study population (median, 4 g/d). Conclusions. Within the range o f light to moderate drinking habits, alcohol consumption was inversely related to fasting and postload insulin levels. This relation did not explain associations of alcohol intake with lipid levels and may inst ead reflect an additional mechanism by which moderate alcohol consumpt ion impacts cardiovascular disease risk.