The Long-Term Effect of Preterm Birth on Renal Function: A Meta-Analysis

Abstract

The preterm-born adult population is ever increasing following improved survival rates of premature births. We conducted a meta-analysis to investigate long-term effects of preterm birth on renal function in preterm-born survivors. We searched PubMed and EMBASE to identify studies that compared renal function in preterm-born survivors and full-term-born controls, published until 2 February 2019. A random effects model with standardized mean difference (SMD) was used for meta-analyses. Heterogeneity of the studies was evaluated using Higgin’s I2 statistics. Risk of bias was assessed using the Newcastle–Ottawa quality assessment scale. Of a total of 24,388 articles screened, 27 articles were finally included. Compared to full-term-born controls, glomerular filtration rate and effective renal plasma flow were significantly decreased in preterm survivors (SMD −0.54, 95% confidence interval (CI), −0.85 to −0.22, p = 0.0008; SMD −0.39, 95% CI, −0.74 to −0.04, p = 0.03, respectively). Length and volume of the kidneys were significantly decreased in the preterm group compared to the full-term controls (SMD −0.73, 95% CI, −1.04 to −0.41, p < 0.001; SMD −0.82, 95% CI, −1.05 to −0.60, p < 0.001, respectively). However, serum levels of blood urea nitrogen, creatinine, and cystatin C showed no significant difference. The urine microalbumin to creatinine ratio was significantly increased in the preterm group. Both systolic and diastolic blood pressures were also significantly elevated in the preterm group, although the plasma renin level did not differ. This meta-analysis demonstrates that preterm-born survivors may be subject to decreased glomerular filtration, increased albuminuria, decreased kidney size and volume, and hypertension even though their laboratory results may not yet deteriorate.

Preterm birth and the risk of chronic disease multimorbidity in adolescence and early adulthood: A population-based cohort study

“…Chronic disease multimorbidity was defined as one individual having records of two or more non-communicable chronic diseases (psychiatric or somatic) during the same or subsequent secondary care episode(s). The diseases constituting multimorbidity were selected based on evidence on commonly occurring diseases among preterm and term born adolescents and young adults [21,24,25,[36][37][38][39][40][41][42][43][44]. Multimorbidity was identified using data on both in-patient and out-patient hospital care (referred to in the Nordic context as specialised healthcare), based on diagnostic codes listed in S1…”

Neonatal hypertension: concerns within and beyond the neonatal intensive care unit

“…There are not only cardiovascular abnormalities but also renal consequences of prematurity and early life events. A systematic review of preterm birth effects on kidneys found those born preterm had a lower glomerular filtration rate, lower effective renal plasma flow, and a higher urine albumin to creatinine ratio compared to those born at term [ 63 ]. They also found smaller kidney length and kidney volume in addition to higher blood pressure in those born preterm.…”

Preterm Birth, Kidney Function and Cardiovascular Disease in Children and Adolescents

“…According to the results of a recent meta-analysis, preterm children and adults presented significantly decreased kidney length and volume, GFR and increased microalbuminuria, whereas serum levels of blood urea nitrogen, creatinine and cystatin C did not present any significant difference between preterm and full-term individuals. This finding indicates that traditional biomarkers may not reflect mild renal impairment as long as the renal function is maintained by the remained nephrons [ 47 ]. In another meta-analysis, children and adults with LBW had approximately 70% greater risk of developing CKD in later life, which was defined as albuminuria, low eGFR or end-stage renal disease (ESRD) [ 48 ].…”

“…Subgroup analyses demonstrated that higher systolic BP was identified from early adolescence until adulthood among those born preterm and that the difference in systolic BP was greater in the extreme and very preterm born individuals compared to term [ 73 ]. In other meta-analyses, where BP was measured by both single-time office and ambulatory BP monitoring, preterm born adults compared to full term presented significantly higher systolic BP (mean difference: 4.2 mmHg), diastolic BP (mean difference: 2.6 mmHg) and 24 h ambulatory systolic BP (difference: 3.1 mmHg) [ 47 , 74 , 75 ]. Moreover, another meta-analysis reported additional differences in both sleeping and awake systolic BP and diastolic BP levels between the groups of preterm and term and significantly higher values of other components of metabolic syndromes, such as fasting glucose, insulin, Homeostasis Model Assessment-Estimated Insulin Resistance Index and total cholesterol levels in the group of preterm [ 75 ].…”