Alcohol drinking patterns and risk of type 2 diabetes mellitus among younger women.

OBJECTIVE: To examine the relationship between alcohol consumption and the incidence of type 2 diabetes mellitus among relatively young and middle-aged women.
METHODS: In a prospective study, 109 690 women, aged 25 to 42 years, without a history of coronary heart disease, stroke, cancer, or diabetes mellitus completed a detailed lifestyle and medical history questionnaire in 1989. During 10 years of follow-up, we documented 935 incident cases of type 2 diabetes mellitus.
RESULTS: We found a nonlinear relationship between alcohol consumption and risk of type 2 diabetes mellitus after adjustment for multiple confounders, including body mass index, smoking, physical activity, and family history of diabetes mellitus (quadratic trend P =.003). Compared with lifelong abstainers, the adjusted relative risks (95% confidence intervals) were 0.80 (0.66-0.96) for those consuming 0.1 to 4.9 g/d, 0.67 (0.50-0.89) for those consuming 5.0 to 14.9 g/d, 0.42 (0.20-0.90) for those consuming 15.0 to 29.9 g/d, and 0.78 (0.34-1.78) for those consuming 30.0 g/d or more. Further adjustment for dietary factors, including glycemic load, trans-fatty acid, polyunsaturated fat, and total fiber intake, did not appreciably alter these findings. The inverse association with light to moderate drinking was most apparent in women who reported wine or beer drinking. Women who reported 30.0 g/d or more of liquor intake showed a significantly increased risk of diabetes mellitus compared with those who did not report liquor intake (adjusted relative risk, 2.50; 95% confidence interval, 1.00-6.23).
CONCLUSION: Light to moderate alcoholic beverage consumption may be associated with a lower risk of type 2 diabetes mellitus among women aged 25 to 42 years, although this benefit may not persist at higher levels.