Young adults born moderately to extremely preterm have higher eGFR and cystatin C compared to young adults born at term

Adolescents and adults born preterm are at increased risk for kidney dysfunction, possibly secondary to incomplete nephrogenesis. However, few long-term follow-up studies are available from U.S.-born preterm cohorts. Using the Parkland Hospital Neonatal Intensive Care Unit Registry (Dallas, TX), patients aged 12–40 years born ≤ 32 weeks gestation or < 1500 g were recruited, along with healthy term-born similarly aged participants. Study procedures included anthropometrics, vitals, and basic laboratory testing. Glomerular filtration rate (eGFR) was calculated using the CKD-Epi Creatinine Equation (2021). Least squares regressions were used to determine the main effect of neonatal and adult factors on markers of kidney function. Participants included 103 preterm (GA 29.5 ± 2.5 wks, current age 26.1 ± 6.0 yrs) and 43 term (GA 39.2 ± 1.1 wks; current age 29.1 ± 7.3 yrs) individuals. Patients born prematurely had similar creatinine (0.73 ± 0.21 vs. 0.82 ± 0.21 mg/dL; p = 0.112), higher eGFR (120.5 ± 17.76 vs. 112.4 ± 16.28 mL/min/1.73 m2; p = 0.003), and higher cystatin C (12.15 ± 3.17 vs. 11.46 ± 2.66 µg/mL; p = 0.035) in adolescence/adulthood compared to term, respectively. Multivariate linear regression demonstrated that gestational age was significantly related to eGFR and cystatin C, where lower GA was associated with higher eGFR but also higher cystatin C. Despite similar creatinine, individuals born prematurely had higher eGFR and higher cystatin C. The elevated eGFR suggests a potential hyperfiltrative state, while the elevated cystatin C suggests increased risk for progression to chronic kidney disease. A higher resolution version of the Graphical abstract is available as Supplementary information.