Pneumonia and mortality risk in continuous ambulatory peritoneal dialysis patients with diabetic nephropathy

Abstract

Background: Although clinical experience suggests that patients with diabetes mellitus are more susceptible to several types of infections, the overall scope of pneumonia in continuous ambulatory peritoneal dialysis (CAPD) patients with diabetic nephropathy (DN) has received little attention.

Methods: This was a prospective observational cohort study in CAPD patients in which prognostic risks of pneumonia were evaluated in DN and non-DN patients by Cox regression analysis. Hazard ratios of pneumonia events, all-cause and pneumonia-related mortality were calculated by Kaplan-Meier curves and the Cox proportional hazards model for DN versus non-DN patients.

Results: A total of 1148 patients (58.6% male, 48.34±15.78 years) had a median follow-up of 23.8 months and a maximum follow-up of 72.0 months. The pneumonia incidence rate of 62.3/1,000 patient-years in CAPD patients with DN was significantly higher than that of 28.5/1,000 patient-years in non-DN patients. On multivariate analysis, independent predictors of pneumonia occurrence in CAPD patients with DN were high body mass index (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.01-1.31; P = 0.037) and low serum albumin level (HR, 0.87; 95% CI, 0.78-0.98; P = 0.014). Older age (HR, 1.63; 95% CI, 1.35-1.96; P<0.001) was an independent risk factor for the presence of pneumonia in non-DN patients. CAPD patients with DN had higher pneumonia-related mortality (HR, 4.424; 95% CI, 1.871-10.461; P<0.001) and all-cause mortality (HR, 2.608; 95% CI, 1.890-3.599; P<0.001) hazards than their non-DN counterparts, even when extensive demographics, comorbidities, and lab adjustments were made.

Conclusions: The pneumonia and all-cause mortality risks were strikingly higher in CAPD patients with DN than in non-DN counterparts, which may warrant further investigation and therapeutic care intensification.

Figure 1. Cumulative incidence of pneumonia events according to diabetic nephropathy.

Figure 2. Cumulative incidences of all-cause and pneumonia-related death according to diabetic nephropathy.

(A) Cumulative hazard of all-cause death. The HR in the DN, as compared with non-DN, was 2.608 (95% CI, 1.890–3.599). (B) Cumulative hazard of pneumonia death, for which the HR in the DN group was 4.424 (95% CI, 1.871–10.461).

Figure 3. The hazard ratios of diabetic nephropathy on CAPD for the prediction of all-cause and pneumonia-related mortality.

(A) All-cause mortality and (B) pneumonia-related mortality by diabetic nephropathy. BMI, body mass index; eGFR, estimated glomerular filtration rate; MAP, mean artery pressure; CRP, C-reactive protein; HDL-C, high-density lipoprotein; LDL-C, low-density lipoprotein; HR, hazard ratio; CI, confidence interval.