To investigate the association between birth weight, infant growth rate, and childhood adiposity as a proxy for adult metabolic or cardiovascular risk in a Chinese population with a history of recent and rapid economic development.
Prospective study in a population-representative birth cohort.
Hong Kong Chinese population.
Six thousand seventy-five term births (77.5% successful follow-up).
Birth weight and growth rate (change in the weight z score) at ages 0 to 3 and 3 to 12 months.
Main Outcome Measure: Body mass index (BMI) (calculated as the weight in kilograms divided by the height in meters squared) z score at about age 7 years.
Each unit increase in the weight z score at ages 0 to 3 and 3 to 12 months increased the BMI z score by 0.52 and 0.33, respectively. Children in the highest birth weight and growth rate tertiles had the highest BMI z scores. In the lowest birth weight tertile, increases in the weight z score at ages 0 to 3 months had a larger effect on the BMI z score in boys (mean difference, 0.88; 95% confidence interval 0.69-1.07) than in girls (mean difference, 0.52; 95% confidence interval, 0.33-0.71); these differences by birth weight, growth rate at ages 0 to 3 months, and sex were significant (P=.007).
Faster prenatal and postnatal growth were associated with higher childhood BMI in a population with a recent history of rapid economic growth and relatively low birth weight, suggesting that maximal growth may not be optimal for metabolic risk. However, there may be a developmental trade-off between metabolic risk and other outcomes.
Hui LL‡, Schooling CM, Leung SSL, Mak KH, Ho LM, Lam TH, Leung GM. (2008) Birth Weight, Infant Growth, and Childhood Body Mass Index: Hong Kong’s Children of 1997 Birth Cohort, Arch Pediatr Adolesc Med 162(3):212-218.