Patterns of Growth Associated With the Timing of Adiposity Rebound

Abstract

This study was undertaken to evaluate the effects of age of adiposity rebound (AR) on measures of fat mass between ages 7 and 11 years, maturity, and adiposity in 458 children from a birth cohort studied to age 26 years. Patterns of growth between ages 3 and 26 years and changes in fat mass index between 7 and 11 years in groups with early (<5.5 years for boys and <5 years for girls), average (between 5.5 and 7.5 years for boys and between 5 and 7 years for girls), and late AR (> or =7.5 years for boys and > or =7 years for girls) are described. The mean z-scores for BMI, height, and weight increased between age 3 years and adolescence in the early-rebound group and decreased in the late-rebound group. The differences were maintained until adulthood for BMI and weight. Disproportionately high increases in fat mass index during growth (7-11 years), more advanced bone age in boys at age 7 years, and earlier menarche in girls were evident in the early-rebound group. The relative risks at 26 years of being overweight (BMI 25-29.9 kg/m(2)) and obese (BMI > or =30 kg/m(2)) were 2.70 (95% confidence interval (CI): 1.55, 4.66) and 5.91 (95% CI: 3.03, 11.55) respectively, using the average group as the reference. The corresponding relative risks for adult waist girths exceeding international cut points were 2.12 (95% CI: 1.09, 4.13) and 3.32 (95% CI: 1.46, 7.54). Thus, early rebound is associated with increased depositions of fat in middle childhood, and risks associated with early rebound persist at least until early adulthood.