WEIGHT-BEARING ACTIVITY DURING YOUTH IS A MORE IMPORTANT FACTOR FOR PEAK BONE MASS THAN CALCIUM INTAKE

In a 15 year longitudinal study (Amsterdam Growth and Health Study) is evaluated the effect of daily calcium intake (CAI) during adolescence and young adulthood on the development of peak bone mass at age 27 wh en the influence of weight-bearing activity (WBA) and body weight was accounted for. A group of 84 males and 98 females were measured longit udinally from age 13 until age 28. Measurements were taken six times o f anthropometric characteristics. Lifestyle was also evaluated six tim es by cross-check interviews of CAI and WBA. Bone mineral density (BMD ) of the lumbar spine was determined at age 27 by dual x-ray absorptio n. Three periods were considered, that is, the adolescent period, the period 13-21 years, and the total period (13-27 years). In multiple li near regression analyses, only WBA and body weight were significant po sitive contributors to the final model of lumbar BMD at age 27. In all three periods WBA was the best predictor in males and body weight in females. ANOVA was performed on BMD and the highest and lowest quartil es of calcium intake with the significant predictor variables of the l inear regression model as covariates. Again calcium intake appeared no t a significant predictor of BMD in the three periods in both sexes. R egular weight-bearing exercise and at least a normal age-related body weight in adolescence and young adulthood are of key importance in rea ching the highest lumbar peak bone mass at the age of 27 years.