Influencing factors for residual kidney function in incident peritoneal dialysis patients: a systematic review and meta-analysis

BACKGROUND

Residual kidney function (RKF) impacts patients' survival rate and quality of life when undergoing peritoneal dialysis (PD). This meta-analysis was conducted to systematically identify risk and protective factors associated with RKF decline and loss.

METHODS

We searched three English and one Chinese databases from inception to January 31, 2023, for cohort and cross-sectional studies exploring factors associated with RKF decline or loss. The random effects model was employed to aggregate risk estimates and 95% confidence intervals (CIs) from multivariate analysis. Sensitivity and subgroup analyses were performed to explore the heterogeneity among the studies.

RESULTS

Twenty-seven studies comprising 13549 individuals and 14 factors were included in the meta-analysis. Based on the meta-analysis results, risk factors involving male gender (hazard ratio (HR) 1.689, 95%CI 1.385-2.061), greater body mass index (BMI) (odds ratio (OR) 1.081, 95% confidence interval (CI) 1.029-1.135), higher systolic blood pressure (SBP) (HR 1.014, 95%CI 1.005-1.024), diabetes mellitus (DM) (HRRKF loss 1.873, 95%CI 1.475-2.378), DM (ORRKF decline 1.906, 95%CI 1.262-2.879), peritonitis (relative ratio (RR) 2.291, 95%CI 1.633-3.213), proteinuria (OR 1.223, 95%CI 1.117-1.338), and elevated serum phosphorus (RR 2.655, 95%CI 1.679-4.201) significantly contributed to the risk of RKF decline and loss in PD patients. Conversely, older age (HR 0.968, 95%CI 0.956-0.981), higher serum albumin (OR 0.834, 95%CI 0.720-0.966), weekly Kt/V urea (HR 0.414, 95%CI 0.248-0.690), baseline urine volume (UV) (HR 0.791, 95%CI 0.639-0.979), baseline RKF (HR 0.795, 95%CI 0.739-0.857) exhibited protective effects. However, diuretics use, automatic peritoneal dialysis (APD) modality and baseline RKF did not significantly impact RKF decline.

CONCLUSIONS

Patients with male gender, greater BMI, higher SBP, DM, peritonitis, proteinuria, and elevated serum phosphorus might have a higher risk of RKF decline and loss. In contrast, older age, higher serum albumin, weekly Kt/V urea, baseline UV, and baseline RKF might protect against RKF deterioration.

Association between gestational visit-to-visit blood pressure variability and adverse neonatal outcomes

The authors aimed to explore the association between visit‐to‐visit blood pressure variability (BPV) in pregnant women and adverse neonatal outcomes. The study included 52 891 pregnant women. BPV was calculated as standard deviation (SD) and coefficient of variation (CV) of systolic blood pressure (SBP) or diastolic blood pressure (DBP). All participants were divided into four groups by the quartiles of BPV. When comparing the highest quartiles to the lowest quartiles of DBP SD in all participants, the fully adjusted ORs were 1.19 (95% CI 1.11–1.27, p for trend < .001) for fetal distress, 1.32 (95% CI 1.14–1.54, p for trend < .001) for small for gestational age, 1.32 (95% CI 1.06–1.63, p for trend = .003) for 1‐min Apgar score ≤ 7. When comparing the highest quartiles to the lowest quartiles of DBP CV, ORs were 1.22 (95% CI 1.14–1.30, p for trend < .001) for fetal distress, 1.38 (95% CI 1.17–1.61, p for trend < .001) for small for gestational age, 1.43 (95% CI 1.14–1.79, p for trend < .001) for 1‐min Apgar score ≤ 7. ORs for preterm birth and 5‐min Apgar score ≤ 7 were not statistically significant. However, in participants with gestational hypertension or preeclampsia, ORs for preterm birth were 2.80 (95% CI 1.99–3.94, p for trend < .001) in DBP SD and 3.25 (95% CI 2.24–4.72, p for trend < .001) in DBP CV when extreme quartiles were compared. In conclusion, higher visit‐to‐visit BPV was associated with adverse neonatal outcomes.

Baseline and Time-Averaged Values Predicting Residual Renal Function Decline Rate in Japanese Peritoneal Dialysis Patients

Residual renal function (RRF) is a strong prognostic factor of morbidity and mortality in patients undergoing peritoneal dialysis (PD). We determined predictors of the RRF rate of decline using both baseline values and time-averaged ones. We retrospectively analyzed 94 patients being treated with PD at the Japanese Red Cross Medical Center. The decline rate of RRF was calculated by a diminution in the weekly renal Kt/V between the first and last follow up divided by follow-up years. The mean follow-up period was 2.28 years, and the mean decline rate of weekly renal Kt/V was 0.25 per year. A multivariate analysis using baseline parameters identified dialysis-to-plasma ratios of creatinine at 4 h (P = 0.02), urinary protein (P = 0.02), and mean blood pressure (MBP) (P < 0.01) as being positively associated with the RRF rate of decline, while the use of angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) had a negative correlation (P = 0.03). When using time-averaged values as independent variables, a lower weekly total renal Kt/V (P < 0.0001), higher urinary protein (P < 0.0001), and higher MBP (P = 0.04) independently predicted a faster RRF rate of decline. We demonstrated that PD patients with a lower MBP and lower urinary protein both at baseline and throughout their PD duration had a slower RRF rate of decline. We recommend strict control of blood pressure and anti-proteinuric therapy for PD patients.