Plasma copeptin is increased and associated with smaller kidney volume in young adults born very preterm

Background Plasma copeptin, a surrogate marker for vasopressin levels, is increased in neonates born preterm, particularly in those with a more severe neonatal course, as reflected by bronchopulmonary dysplasia. Copeptin levels in adulthood are unknown. Methods In this case-control study of 101 adults born very preterm (<30 weeks of gestation) and 105 control adults born full-term, a comprehensive clinical and biological assessment was performed, including blood pressure measurements, kidney ultrasound and determination of plasma copeptin, renin activity, angiotensin II, aldosterone, apelin, sodium and potassium, serum and morning urine osmolality. Results The median age in the study was 23.1 years [interquartile range (IQR) 21.2-24.8] and 57% were females. In males, the median copeptin levels were 8.2 pmol/L (IQR 6.3-12.4) and 6.1 pmol/L (IQR 4.3-9.0) in the preterm and term groups, respectively (P = 0.022). In females, the median copeptin levels were 5.2 pmol/L (IQR 3.9-7.6) and 4.0 pmol/L (IQR 2.8-5.7) in the preterm and term groups, respectively (P = 0.005). Adults born preterm with a history of bronchopulmonary dysplasia had further increased copeptin levels. The kidney volume, adjusted for height, was smaller and albuminuria was higher in the preterm group, and both were associated with higher plasma copeptin levels. Conclusions Plasma copeptin is higher in young adults born preterm and is related to a more severe neonatal course and smaller kidney volume.