Tracking of size-adjusted bone mineral content and bone area in boys and girls from 10 to 17years of age

Positive correlations for bone mineral content (BMC) between 10 and 17years of age were found for boys and girls after adjusting for body size, puberty, and diet. This tracking of BMC indicated that osteoporosis prevention should begin already in prepuberty. Introduction: Previous studies indicate that BMC is tracking during growth, but it remains unclear whether this would remain significant after adjusting for important confounders. We tested the hypothesis that BMC and bone area (BA) track from 10 to 17years of age, independently of body size, pubertal stage, and dietary intake of energy, calcium and protein. Methods: A longitudinal study where whole body (T) and lumbar spine (LS) BMC and BA (dual-energy X-ray absorptiometry) and dietary intake (7-day food records) were assessed at 10 and 17years of age in boys and girls (n=91). Tracking of bone variables from 10 to 17years was estimated by Pearson's correlations adjusted for the selected confounders. Results: The unadjusted correlations for T-BMC between 10 and 17years, likewise for LS-BMC and T-BA, were positive for both sexes (0.51-0.81; P