Is infant weight associated with childhood blood pressure? Analysis of the Promotion of Breastfeeding Intervention Trial (PROBIT) cohort

Results In boys, after controlling for confounders and prior weight gain, the change in systolic blood pressure per z-score increase in weight gain was 0.09 mmHg [95% confidence interval (95% CI) � 0.14 to 0.31] for birthweight; 0.41 mmHg (95% CI 0.19–0.64) for birth to 3 months; 0.69 mmHg (95% CI 0.47–0.92) for 3 months to 1 year and 0.82 mmHg (95% CI 0.58–1.06) for 1–5 years. Most of the associations between weight gain and blood pressure were mediated through weight at the age of 6.5 years. Findings for girls and diastolic blood pressure were similar. Conclusions Children who gained weight faster than their peers, particularly at later ages, had higher blood pressure at the age of 6.5 years, with no association between birthweight and blood pressure.