Objective: The objective of this study was to investigate the association of 4-year changes in alcohol consumption with a subsequent risk of type 2 diabetes.
Research design and methods: We prospectively examined 38,031 men from the Health Professionals Follow-Up Study who were free of diagnosed diabetes or cancer in 1990. Alcohol consumption was reported on food frequency questionnaires and updated every 4 years.
Results: A total of 1,905 cases of type 2 diabetes occurred during 428,497 person-years of follow-up. A 7.5 g/day (approximately half a glass) increase in alcohol consumption over 4 years was associated with lower diabetes risk among initial nondrinkers (multivariable hazard ratio [HR] 0.78; 95% CI: 0.60-1.00) and drinkers initially consuming <15 g/day (HR 0.89; 95% CI: 0.83-0.96), but not among men initially drinking ≥15 g/day (HR 0.99; 95% CI: 0.95-1.02; P(interaction) < 0.01). A similar pattern was observed for levels of total adiponectin and hemoglobin A(1c), with a better metabolic profile among abstainers and light drinkers who modestly increased their alcohol intake, compared with men who either drank less or among men who were already moderate drinkers and increased their intake. Likewise, compared with stable light drinkers (0-4.9 g/day), light drinkers who increased their intake to moderate levels (5.0-29.9 g/day) had a significantly lower risk of type 2 diabetes (HR 0.75; 95% CI: 0.62-0.90).
Conclusions: Increases in alcohol consumption over time were associated with lower risk of type 2 diabetes among initially rare and light drinkers. This lower risk was evident within a 4-year period following increased alcohol intake.