Growth in childhood predicts hip fracture risk in later life

The incidence of hip fracture was estimated in 6,370 women born in Helsinki between 1934 and 1944. Women in the lowest quarter of adiposity gain had an 8.2-fold increase in hip fracture risk compared with those in the highest quarter (p < 0.001). These data point to a relationship between childhood growth and fracture risk during later life. Previous findings show that discordance between childhood increase in height and weight is associated with an increased risk of osteoporotic fractures during later life. We studied 6,370 women born in Helsinki between 1934 and 1944. Each woman's birth weight and length at birth was recorded, as well as her height and weight through childhood. We identified the occurrence of hip fracture through the National Finnish Hospital discharge register. There were 49 hip fractures in the 6,370 women over 187,238 person-years of follow-up. Hip fracture was associated with increasing Z-scores for height between 1 and 12 years, not matched by a corresponding increase in weight. Therefore, reduction in the Z-score for body mass index was associated with increased risk of hip fracture. Women in the lowest quarter of change in Z-scores for body mass index had an 8.2-fold increase in hip fracture risk (95% CI 1.9 to 35), compared with those in the highest quarter (p < 0.001). Thinness in childhood is a risk factor for hip fracture in later life. This could be a direct effect of low fat mass on bone mineralization, or represent the influence of altered timing of pubertal maturation.