Impact of smoking on bone mineral density and bone metabolism in elderly men: the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study

Our cross-sectional analysis of 1,576 men aged a parts per thousand yen65 years examined smoking effects on bone status. Number of smoking years was associated with decreased bone mineral density (BMD), after adjusting for age, height, weight, and number of cigarettes smoked daily. Smoking did not affect biochemical marker serum values for bone turnover. The impact of smoking on bone status in men has not been conclusively established. We examined how smoking and its cessation influence bone status and metabolism in men. We analyzed 1,576 men among a baseline survey of Japanese men aged a parts per thousand yen65 years, the Fujiwara-kyo Osteoporosis Risk in Men study, conducted during 2007-2008. Lumbar spine (LS) BMD values among never, former, and current smokers were 1.045 +/- 0.194, 1.030 +/- 0.189, and 1.001 +/- 0.182 g/cm(2) (P = 0.005), respectively, while total hip (TH) BMD values were 0.888 +/- 0.120, 0.885 +/- 0.127, and 0.870 +/- 0.124 (P = 0.078), respectively. The significant trend for LS BMD remained after adjusting for the covariates; age, height, weight, physical activity, milk consumption, and drinking habit (P = 0.036). Among never and ever (current and former) smokers, LS and TH BMD decreased with the number of pack years or the number of smoking years, respectively, adjusted for those covariates. Among ever smokers, LS and TH BMD decreased with the number of smoking years after adjusting for age, height, weight, and number of cigarettes smoked daily. Smoking did not reveal significant effect for serum osteocalcin or tartrate resistant acid phosphatase isoenzyme 5b. The impact of smoking on bone status is mainly associated with the number of smoking years in elderly men.