Prospective study of cigarette smoking, alcohol use, and the risk of diabetes in men.

OBJECTIVE

To examine the association between smoking, alcohol consumption, and the incidence of non-insulin dependent diabetes mellitus in men of middle years and older.

DESIGN

Cohort questionnaire study of men followed up for six years from 1986.

SETTING

The health professionals' follow up study being conducted across the United States.

SUBJECTS

41,810 male health professionals aged 40-75 years and free of diabetes, cardiovascular disease, and cancer in 1986 and followed up for six years.

MAIN OUTCOME MEASURE

Incidence of non-insulin dependent diabetes mellitus diagnosed in the six years.

RESULTS

During 230,769 person years of follow up 509 men were newly diagnosed with diabetes. After controlling for known risk factors men who smoked 25 or more cigarettes daily had a relative risk of diabetes of 1.94 (95% confidence interval 1.25 to 3.03) compared with non-smokers. Men who consumed higher amounts of alcohol had a reduced risk of diabetes (P for trend < 0.001). Compared with abstainers men who drank 30.0-49.9 g of alcohol daily had a relative risk of diabetes of 0.61 (95% confidence interval 0.44 to 0.91).

CONCLUSIONS

Cigarette smoking may be an independent, modifiable risk factor for non-insulin dependent diabetes mellitus. Moderate alcohol consumption among healthy people may be associated with increased insulin sensitivity and a reduced risk of diabetes.