The influence of cigarette smoking and age on bone loss in men.

Hand X-rays were examined among 341 healthy male participants (age 40-80 yr) of the Normative Aging Study who had two successive X-rays 3 to 5 yr apart. Bone density was estimated at midshaft of the second metacarpal as percent cortical area. As expected, cross-sectional analysis revealed a decrease in percent cortical area with age. Current smokers tended to have slightly lower percent cortical areas than "never" smokers. When participants were followed longitudinally over a 3 to 5 year period, a trend toward greater bone loss with increasing age was generally observed in both smoking status groups, although smokers' rate of loss after age 55 yr deviated slightly from this pattern. Current smokers under age 55 yr consistently showed greater bone loss than never smokers.