Bone mineral density changes in young women: a two year study.

Achievement of a high peak bone mass is considered a pivotal preventive strategy against future osteoporotic fractures. The ostensible interaction between physiology and lifestylefor the development of bone mass over time is sparsely outlined among young women. The aim of this study was to follow bone density and bone resorption over time among healthy young women in relation to lifestyle factors and to evaluate the perceived influence of other factors. Data were collected in 1999 and in 2001. Healthy young women (n=152) were given a structured questionnaire, a heel bone scanner (dual X-ray absorptiometry) performed bone mineral density measurements and deoxypyridinoline was measured in urine. Data were analyzed by linear, multiple and logistic regression analysis. Mean bone mineral density (BMD) was 0.562 g/cm2 (+/-0.090). Bone density at baseline was the best predictorfor the bone density atfollow-up. Bone density at baseline together with smoking and alcohol (dichotomized) accounted for 86.5% of the variation in bone density 2 years later. Of the participants 62% had decreased/unchanged bone density and 38% had increased their bone density from 1999 to 2001. Use of oral contraceptives or alcohol at baseline was associated with an increased risk of belonging to the group who decreased their bone density. Deoxypyridinoline was not a strongpredictor to bone density and all potential predictors of deoxypyridinoline had a minor influence (<10%). In conclusion, lifestyle behaviors such as use of oral contraceptives, smoking and alcohol consumption seem to have a negative influence on BMD development among young women and warrant further scrutiny.