High blood pressure at early school age among extreme preterms

BACKGROUND AND OBJECTIVES: Former preterm infants are at increased risk of hypertension with increasing age. Our objective was to identify rates of high blood pressure (BP) (≥90th percentile) and hypertension (BP ≥95th percentile) and associated risk factors among extreme preterm (EPT) infants at 6 to 7 years of age. METHODS: Assessment included BP and anthropometrics. Comparisons were made by BP ≥90th versus <90th percentile. Regressions were run to identify relative risk (RR) of factors associated with BP ≥90th percentile. RESULTS: Among 379 EPT infants, 20.6% had systolic high BP, 10.8% systolic hypertension, 21.4% diastolic high BP, and 11.4% diastolic hypertension. Children with systolic high BP had higher rates of BMI, triceps skinfolds >85th percentile, and waist circumference >90th percentile. In regression analyses, weight gain velocity from 18 months to school age (RR = 1.36), and maternal gestational diabetes (MGD) (RR = 2.04) predicted systolic and either systolic and/or diastolic high BP (RR = 1.27 and RR = 1.67). Among children with BMI <85th percentile, 17% had systolic and 19% had diastolic high BP. Regression analysis for normal weight children indicated public insurance (RR = 2.46) and MGD (RR = 2.16) predicted systolic high BP, and MGD (RR = 2.08) predicted either systolic or diastolic high BP. CONCLUSIONS: Both overweight and normal weight EPT children are at risk for high BP and hypertension. Public insurance, MGD, and weight gain velocity are risk factors. Findings of high BP among EPT children at early school age are worrisome and indicate a need for close follow-up.