Early sexual maturation, central adiposity and subsequent overweight in late adolescence. A four-year follow-up of 1605 adolescent Norwegian boys and girls: the Young HUNT study

Background: Early sexual maturation has been associated with overweight that may persist after the completion of biological growth and development. We have prospectively examined the influence of early sexual maturation on subsequent overweight in late adolescence and assessed if this association was modified by central adiposity in early adolescence. Methods: 1605 Norwegian adolescents were followed from early ( baseline, mean age 14.2 years) to late adolescence (follow-up, mean age 18.2 years). Maturational timing was assessed by self-reports of pubertal status (PDS) in boys and age at menarche (AAM) in girls. Central adiposity was classified according to waist circumference ( waist) measured at baseline, using age and gender specific medians as cut off. Overweight was classified according to International Obesity Task Force (IOTF) standards. Results: At follow-up, early sexual maturation in girls, but not in boys, was associated with overweight. This association, however, was restricted to girls with high waist circumference (> median) at baseline ( OR, 2.7, 95% CI 1.5 - 4.9). Thus, age at menarche was not associated with overweight in girls with low waist (<= median) at baseline. Central adiposity was, independent of maturational timing, associated with higher BMI at follow-up in both genders, but differences were more pronounced among early matured girls (3.5 kg/m(2)), than among intermediate ( 2.7 kg/m(2)) and late matured girls ( 1.2 kg/m(2)). Conclusion: In girls, the combination of central adiposity and early age at menarche appears to increase the risk of being overweight in late adolescence.