Early, preterm birth predict CKD development from childhood into mid-adulthood
Preterm and early term birth are independently associated with a higher risk of chronic kidney disease (CKD) from childhood into mid-adulthood, according to a study.
“People born prematurely need long-term follow-up for monitoring and preventive actions to preserve renal function across the life course,” researchers said.
Of the 4,186,615 singleton live births analysed, 4,305 (0.1 percent) were diagnosed with CKD during 87.0 million person-years of follow-up. [BMJ 2019;365:l1346]
Individuals born preterm or extremely preterm (<28 weeks) had nearly twofold (adjusted hazard ratio [aHR], 1.94, 95 percent CI, 1.74–2.16; p<0.001) and threefold (aHR, 3.01, 1.67–5.45; p<0.001) risks of CKD, respectively, from birth into mid-adulthood. Even those born at early term (37–38 weeks) were also at increased risk of CKD (aHR, 1.30, 1.20–1.40; p<0.001).
The association between preterm birth and CKD was strongest at ages 0–9 years (aHR, 5.09, 4.11–6.31; p<0.001). This relation weakened but remained elevated at ages 10–19 years (aHR, 1.97, 1.57–2.49; p<0.001) and 20–43 years (aHR, 1.34, 1.15–1.57; p<0.001). Both males and females were affected by such associations, which appeared to have no link to shared genetic or environmental factor in families.
“As previously reported, there may already be a silent epidemic of CKD among those who were born preterm. CKD is often under-recognized but has an estimated prevalence of 5–10 percent in general adult populations, which might be substantially higher among those born prematurely,” researchers said. [Pediatrics 2013;131:1168-1179; Am J Nephrol 2014;39:306-313; Curr Opin Nephrol Hypertens 2017;26:187-196; Lancet 2012;379:815-822]
In addition to preterm birth, other risk factors for CKD included male sex, congenital anomalies and maternal obesity, which were found to be consistent with previous findings. [Medicine (Baltimore) 2016;95:e3013; Can J Kidney Health Dis 2015;2:27; Pediatr Nephrol 2010;25:687-697; Nephrology (Carlton) 2018;23(Suppl 4):84-87; Biosci Rep 2018;38:BSR20180050]
In contrast to an earlier report, researchers found an association between maternal pre-eclampsia and an increased risk of CKD in the offspring. Furthermore, previous studies have shown that maternal pre-eclampsia correlated with development of hypertension and cardiovascular disease in the offspring. [J Am Soc Nephrol 2008;19:151-157; Curr Hypertens Rep 2014;16:475]
“Our findings underscore the importance of … strategies to prevent preterm birth, including better access to preconception and prenatal care for high-risk women, and reduction of nonmedically indicated deliveries before full term,” researchers said. [MMWR Morb Mortal Wkly Rep 2016;65:826-830]
The current cohort study included singleton live births in Sweden during 1973–2014. Gestational age at birth was identified from nationwide birth records in the Swedish birth registry, while CKD was identified from nationwide inpatient and outpatient diagnoses through 2015 (maximum age, 43 years).
Gestational age at birth and CKD risk were examined using Cox regression while adjusting for potential confounders. Co-sibling analyses were performed to assess the influence of unmeasured shared familial (genetic or environmental) factors.