Birth weight, postnatal weight change, and risk for high blood pressure among Chinese children

BACKGROUND: It is hypothesized that a physiological predisposition toward hypertension results from a combination of intrauterine growth restriction or overgrowth and excessive postnatal weight gain. Previous studies were conducted largely in Western countries however the hypothesis may also be relevant in developing countries where metabolic disorders are increasing. OBJECTIVE: We investigated the association of birth weight and postnatal weight gain with hypertension among Chinese children. METHODS: A population based study was conducted among 15 600 children aged 3 to 6 years from Tianjin, China. Weight was expressed as z scores. Postnatal weight gain was defined as changes in z scores from birth to 3 to younger than 4 years, 4 to younger than 5 years, and 5 to 6 years. Hypertension was defined as greater than the 90th percentile of either systolic or diastolic blood pressure. Logistic regression-derived odds ratios and 95% confidence intervals were generated to estimate the association between birth weight and postnatal weight gain with hypertension risk in childhood. RESULTS: Birth weight was positively associated with childhood hypertension in boys and girls (odds ratios [95% confidence interval] comparing extreme quartiles [high versus low] were 5.67 [3.83- 8.39] and 2.58 [3.83- 8.39], respectively). Postnatal weight gain was positively associated with hypertension and the association did not significantly vary by birth size for gestational age. CONCLUSIONS: Greater birth weight or postnatal weight gain was associated with increased childhood hypertension risk, suggesting that intrauterine growth and postnatal weight gain may have implications on health during childhood.