Influence of climatic factors on single-center peritoneal dialysis-associated peritonitis

Peritoneal dialysis associated peritonitis (PDAP), one of the most common complications of peritoneal dialysis, is generally believed as an important factor causing technique failure and increasing hospital admission and fatality rate in peritoneal dialysis patients. Moreover, the prevention and treatment for PDAP have always been considered as an important link in clinical peritoneal dialysis. Thus, the study is performed to investigate the impact of climate factors on the incidence and prognosis of single-center PDAP in Hunan Province, China, which can provide a clinical basis for the prevention and treatment strategy for PDAP.

A total of 885 patients on peritoneal dialysis, who were admitted to Department of Nephrology, Third Xiangya Hospital, Central South University (hereinafter referred to as our hospital) from January 1, 2009 to December 31, 2017, were enrolled as the subjects, and the demographic and clinical data for patients with PDAP from 2009 to 2017 as well as climate data of Hunan Province were collected.The patients were divided into different season groups, and the general information and clinical biochemical indicators in different season groups were compared. The incidence, the proportion of pathogenic bacteria and the clinical outcome of PDAP in the different season groups were compared. The risk factors of PDAP in different season groups were analyzed by using a multivariate logistic regression. Pearson's correlation analysis was used to analyze the correlations of the overall incidence of PDAP with the monthly mean temperature and the monthly mean humidity.

There were 448 cases of PDAP that occurred in the peritoneal dialysis center of our hospital from 2009 to 2017 (9 years), the incidence was 0.17 time/patient-years. The incidence of overall PDAP (0.246 time/patient-years) and the incidence of Gram-negative (G^-) bacterial PDAP (0.048 time/patient-years) in the summer group were the highest compared with the other season groups, with significant difference (all P<0.05). Compared with the spring group (OR=0.321, 95% CI 0.144-0.713; P<0.01), the autumn group (OR=0.419, 95% CI 0.187, 0.937; P<0.05) and the winter group (OR=0.326; 95% CI 0.139, 0.763; P<0.05), the probability suffered from PDAP in the summer group were higher. The patients with low body mass index (BMI) in the spring group were more likely to suffer from PDAP in the summer group. The overall incidences of PDAP (r=0.258, P<0.05) and G^- bacterial PDAP (r=0.278, P<0.05) were significantly positively correlated with the monthly mean temperature in Hunan Province, which was not correlated with the monthly average humidity. The overall cure rate of PDAP was 83%, and there was no difference in the treatment outcomes among the different season groups (all P>0.05).

The climate factors in Hunan, China have a significant impact on the incidence of PDAP in peritoneal dialysis patients in our hospital. Summer is the peak of PDAP, especially G^- bacterial PDAP. Intestinal dysfunction and low BMI are risk factors for the onset of PDAP in summer. High temperature rather than high humidity is correlated with increased incidence of overall PDAP, especially for G^- bacterial PDAP.