Cigarette smoking, alcohol and caffeine consumption, and bone mineral density in postmenopausal women. The Nottingham...

The aim of this analysis was to compare the effects of different measures of cigarette, alcohol and caffeine consumption upon bone mineral density (BMD). Five hundred and eighty postmenopausal women aged 45-59 years at recruitment completed a risk factor questionnaire that contained detailed sections on cigarette, alcohol and caffeine consumption. BMD was measured using dual-energy X-ray absorptiometry. Measurements taken at five bone sites were used: anterior-posterior spine, femoral neck, greater trochanter, radius/ulna and whole body. The data were analyzed using multiple linear regression, adjusting for a number of established BMD risk factors. BMD was more strongly related to the number of months spent smoking than to pack-years of smoking at all five sites (p < 0.05 at four of the five sites). There were significant reductions in BMD when comparing smokers with non-smokers at ages 20, 30 and 40 years, but not for current smoking. Lifetime alcohol consumption and current alcohol consumption did not have an independent association with BMD. However, the heaviest beer drinkers in the sample had a particularly low bone density. Caffeine consumption at various ages was not associated with BMD. The results of these analyses suggest that for predicting BMD a simple history of smoking duration is as good as trying to obtain more detailed smoking information, but that only 25% of the variation in BMD is explained by personal characteristics, family history and lifestyle factors.