Age of attainment of peak bone mass is site specific in Swedish men--The GOOD study.

UNLABELLED: Results from this study suggest that PBM has been attained in the spine and femoral neck, but not in the radius or tibia, in 18- to 20-year-old men, in which an endosteal contraction and increase in cortical volumetric BMD is observed.

INTRODUCTION: Peak bone mass (PBM) is an important determinant for the risk of osteoporosis. In men, the age of attainment of PBM has been under some controversy. The objective of this study was to determine if peak bone mass had been attained, and whether it is site specific, in 18- to 20-year-old Swedish men.

MATERIALS AND METHODS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) Study consists of 1068 men, 18.9 +/- 0.6 years of age. BMD was measured using both DXA and pQCT. Environmental factors, such as dietary intake and physical activity, were assessed through questionnaires. The independent predictors of BMD were assessed through multiple linear regression, including age, height, weight, calcium intake, smoking, and physical activity.

RESULTS AND CONCLUSIONS: We show, in a large well-characterized cohort, that age was not an independent predictor of BMD of the lumbar spine, femoral neck, or total body, indicating that peak BMD has been achieved in these skeletal sites, whereas it was an independent predictor of BMD of the radius, suggesting that peak BMD has not yet been attained in the long bones. pQCT analyses of the radius and the tibia revealed that age was associated with cortical volumetric BMD and endosteal contraction of the radius and tibia. These results show that the age of attainment of PBM is site specific.