Childhood BMI gain may determine future hip fracture risk
MedWire News: Body mass index (BMI) gain during childhood is associated with pubertal timing, which in turn is linked to peak bone mass (PBM) among young women, Swiss research shows.
"These data are in accordance [with] and complement further the reported relationship between childhood BMI gain and hip fracture risk in later life," remark Thierry Chevalley (Geneva University Hospitals) and colleagues.
The researchers assessed the relationship between BMI, menarcheal age (MENA), and bone mineral density (BMD) in a cohort of 124 healthy women, who underwent dual energy X-ray absorptiometry scanning at regular intervals from age 7.9 to 20.4 years, on average.
As reported in the journal Osteoporosis International, BMI at age 7.9 and 8.9 years - when the girls were still prepubertal - was significantly inversely associated with future MENA. The median MENA was 12.9 years.
A gain in BMI from age 1.0 to 8.9 years, and from age 1.0 to 12.4 years was also inversely associated with MENA. Indeed, BMI increased by a mean 2.8 kg/cm2 between the ages of 1.0 and 12.4 years among early maturers (MENA <12.9 years), compared with an increase of 1.0 kg/cm2 among late maturers (MENA >12.9 years) over the same period, a difference that was statistically significant
Furthermore, femoral neck BMD, and tibial cortical thickness and trabecular density at age 20.4 years - when the participants were approaching PBM - were significantly inversely associated with MENA, and positively associated with a BMI change between the ages of 1.0 and 12.4 years.
In addition, early maturers had a consistently greater femoral neck BMD than late maturers between the ages of 7.9 and 20.4 years. This between-group difference was greatest (14.1%) at 12.4 years, after which it declined, but remained statistically significant until 20.4 years (4.8%).
"This study underscores the importance of pubertal timing in age-related fragility fracture risk," Chevalley and co-authors conclude.
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By Laura Dean