Bone mineral accrual and age of attainment of adult bone mass: A 15-year-longitudinal study from pre-adolescence into adulthood

Abstract

Maximizing bone mass during adolescence may protect against osteoporosis in later life. The purposes of this study were to identify the age when bone mass plateaued and to assess the amount of bone mass accrued during the adolescence period. Data were from the Saskatchewan Pediatric Bone Mineral Accrual Study (PBMAS), a mixed longitudinal study of 197 subjects who were measured on at least two occasions between 1991 and 1997. Between 2002 and 2006, 167 subjects were reassessed. Peak height velocity (PHV) was obtained and individual bone mass measurements (DXA HOLOGIC 2000) were aligned by a biological age (years from PHV). Sigmoidal curves were fitted and age where bone mass plateaued was interpolated. Data were analyzed with repeated measures ANOVA. Males reached PHV significantly later than females, 13.5 ± 1.0 and 11.8 ± 1.0 years respectively (p 0.05), but there were significant differences in age of attainment between sites (p < 0.05). Between 1 year after PHV and the attainment of the plateau, another 0% FNnarea, 13% FNBMC, 14% LSarea, 30% LSBMC, 16% Tbarea and 26% TBBMC, were respectively added to the skeleton. In conclusion when controlling for maturation, site specific differences were found in age of attainment of adult values; area attainment always preceded BMC; no gender differences were found. A significant portion of the skeletal mass was laid down over a 6- to 8-year period of growth. Therefore, attention to modifiable determinants of bone mineral accrual during this period of growth would seem warranted and have implications with regards to maximizing adult bone mass.