OBJECTIVE: To determine the prevalence and weight gain as a risk factor of hypertension (HTN) at three years of age and older among extremely low birth weight (ELBW) infants. STUDY DESIGN: Retrospective cohort study of all ELBW infants born and followed up at our institution over 15 years. RESULTS: 204 infants were followed up for [median (inter-quartile range)] 10.2 years (6.9–13.0). Their birth weight and gestational age were (mean±standard deviation) 758±149 g and 26.4±2.1 weeks respectively. At 3 years of age and older, the prevalence of HTN was 7.3% (15/204), and the prevalence of obesity was 13.2% (27/204). Obesity was more prevalent in children with than without HTN [33% (5/15) vs. 12% (22/189); p = 0.01]. In a regression analysis, body mass index (BMI) percentile at 3 years of age and older (p = 0.04) and increase in weight Z scores since birth (p = 0.008) were associated with a higher systolic blood pressure (SBP; R = 0.386, p < 0.001). CONCLUSION: Obesity is prevalent in ELBW infants at three years of age and older, and it is significantly associated with hypertension. An increase in BMI percentile at ≥3 years of age, and the rate of weight gain since birth among ELBW infants are associated with an increase in SBP.
Weight gain and hypertension at three years of age and older in extremely low birth weight infants