Persistent high blood pressure and renal dysfunction in preterm infants during childhood

Background: Infants born very preterm (≤32 weeks gestational age, GA) and very-low birth weight (≤1500 g; PT-VLBW) demonstrate high systolic blood pressure (SBP), renal dysfunction, and obesity at 6 months–3 years and in early adulthood. Their parallel measurement and progression during childhood is unclear. Methods: We reenrolled 62/120 patients originally seen at 1–3 years at 10–13 years and remeasured anthropometric indices, SBP, and serum creatinine (Cr) and cystatin C (cysC) to determine estimated glomerular filtration rate (eGFR). We selected Term-matched Controls at 10–13 years from the 2015–2016 NHANES database at a ratio of 2 Controls:1 Case (124:62). Results: Reenrolled patients were predominantly Hispanic, birth weight 1073 ± 251 g, and GA at birth 28 ± 2 weeks. At 10–13 years, 45% were classified overweight/obese, 48% had SBP ≥ 90th centile (77% considered hypertensive), and 34% had low eGFR (<90 mL min⁻¹ [1.73 m²]⁻¹). Notably, 57% of reenrolled PT-VLBW Cases had low eGFR_cysC at both 1–3 and 10–13 years, P < 0.03. Compared to Controls, Cases had four times the adjusted odds for having an elevated SBP and low eGFR_Cr despite similar proportions with overweight/obesity among Cases and Controls. Conclusions: PT-VLBW infants seen at 1–3 years exhibit obesity, elevated SBP, and low eGFR in infancy and 10–13 years. Although the small sample size may limit conclusions, pediatricians should consider serial evaluations of PT-VLBW throughout childhood. Impact: The association between preterm birth and elevated blood pressure, renal dysfunction, and obesity in young adults begins as early as 1 year and persists at 10–13 years of age.This is the first study reporting serial measurements of blood pressure, renal function, and obesity from infancy to preadolescence in children born very preterm.Fifty-seven percent of preterm 1–3 year olds have persistent low estimated glomerular filtration rate associated with hypertension at 10–13 years.Clinicians should consider serial evaluations of blood pressure, renal function, and obesity throughout infancy and childhood in all preterm births.