Prenatal and postnatal programming of body composition in obese children and adolescents: evidence from anthropometry, DXA and the 4-component model.

BACKGROUND

Low-birth weight has been proposed to programme central adiposity in childhood. However, there is little information on associations between fetal weight gain and fat distribution within obese individuals.

OBJECTIVES

To investigate associations between birth weight and postnatal weight gain with body composition in a sample of obese children and adolescents.

SUBJECTS AND METHODS

Body composition was measured using anthropometry, dual-emission X-ray absorptiometry and the 4-component model in 45 male and 76 female obese individuals aged 5-22 years. General linear models were used to investigate associations between birth weight standard deviation score (SDS), or change in weight SDS between birth and follow-up, and body composition, adjusting for age, pubertal status, height and gender.

RESULTS

Birth weight SDS ranged from -1.86 to 3.46, and was inversely associated with current weight SDS after adjustment for height SDS. Birth weight SDS was weakly associated with waist and hip girths, but not waist-hip ratio or trunk fat, after adjusting for age, height, pubertal status and gender. Change in weight SDS was strongly associated with total and central adiposity.

CONCLUSIONS

Despite incorporating substantial variability, birth weight SDS was only a weak predictor of tissue masses and their distribution in obese children. Variability in central adiposity was more strongly associated with the magnitude of postnatal growth, which in turn was weakly inversely associated with birth weight SDS. In a population uniformly characterised by excess body weight, postnatal weight gain exerted the dominant impact on adiposity and fat distribution.