Alcohol intake as a risk factor for fracture.

High intakes of alcohol have adverse effects on skeletal health, but evidence for the effects of moderate consumption are less secure. The aim of this study was to quantify this risk on an international basis and explore the relationship of this risk with age, sex, and bone mineral density (BMD). We studied 5,939 men and 11,032 women from three prospectively studied cohorts comprising CaMos, DOES, and the Rotterdam Study. Cohorts were followed for a total of 75,433 person-years. The effect of reported alcohol intake on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson model for each sex from each cohort. Covariates examined included age and BMD. The results of the different studies were merged using weighted beta-coefficients. Alcohol intake was associated with a significant increase in osteoporotic and hip fracture risk, but the effect was nonlinear. No significant increase in risk was observed at intakes of 2 units or less daily. Above this threshold, alcohol intake was associated with an increased risk of any fracture (risk ratio [RR] = 1.23; 95% CI, 1.06-1.43), any osteoporotic fracture (RR = 1.38; 95% CI, 1.16-1.65), or hip fracture (RR = 1.68; 95% CI, 1.19-2.36). There was no significant interaction with age, BMD, or time since baseline assessment. Risk ratios were moderately but not significantly higher in men than in women, and there was no evidence for a different threshold for effect by gender. We conclude that reported intake of alcohol confers a risk of some importance beyond that explained by BMD. The validation of this risk factor on an international basis permits its use in case-finding strategies.