BONE-MINERAL DENSITY, SEX STEROIDS, AND MINERAL METABOLISM IN PREMENOPAUSAL SMOKERS

Smoking is related to decreased bone mass and increased risk of osteop orotic fractures. However, the harmful effects of smoking on bone have not been well characterized. The purpose of this study was to assess the repercussions of smoking on bone mass in premenopausal women, and the relationship between these effects and parameters of mineral metab olism and hormone profile. We measured bone mineral density (BMD) in 1 01 premenopausal women (47 smokers, 54 nonsmokers) with dual-energy X- ray absorptiometry (DeXA) of the proximal femur and lumbar spine. In a subgroup of the sample (16 smokers, 15 nonsmokers) we measured bioche mical indicators of mineral metabolism and hormone profile. BMD in the femoral neck, Ward's triangle, and the intertrochanter region was sig nificantly lower in smokers (P < 0.05) than in nonsmokers. Concentrati ons of sex hormone-binding globulin were higher, and free testosterone index (FTI) was lower (P < 0.05) in smokers. We found no significant differences between the groups in parameters of mineral metabolism. Co ncentrations of dehydroepiandrosterone sulfate and free testosterone i ndex were directly correlated with values of BMD in different sites. O ur findings show that smoking by premenopausal women is associated wit h decreased BMD and characteristic changes in the hormone profile.