Peritoneal dialysis-related peritonitis as a risk factor for cardiovascular events

Transcriptomic analysis identifies novel candidates in cardiorenal pathology mediated by chronic peritoneal dialysis

Peritoneal dialysis (PD) is associated with increased cardiovascular (CV) risk. Studies of PD-related CV pathology in animal models are lacking despite the clinical importance. Here we introduce the phenotypic evaluation of a rat model of cardiorenal syndrome in response to chronic PD, complemented by a rich transcriptomic dataset detailing chronic PD-induced changes in left ventricle (LV) and kidney tissues. This study aims to determine how PD alters CV parameters and risk factors while identifying pathways for potential therapeutic targets. Sprague Dawley rats underwent Sham or 5/6 nephrectomy (5/6Nx) at 10 weeks of age. Six weeks later an abdominal dialysis catheter was placed in all rats before random assignment to Control or PD (3 daily 1-h exchanges) groups for 8 days. Renal and LV pathology and transcriptomic analysis was performed. The PD regimen reduced circulating levels of BUN in 5/6Nx, indicating dialysis efficacy. PD did not alter blood pressure or cardiovascular function in Sham or 5/6Nx rats, though it attenuated cardiac hypertrophy. Importantly PD increased serum triglycerides in 5/6Nx rats. Furthermore, transcriptomic analysis revealed that PD induced numerous changed transcripts involved with inflammatory pathways, including neutrophil activation and atherosclerosis signaling. We have adapted a uremic rat model of chronic PD. Chronic PD induced transcriptomic changes related to inflammatory signaling that occur independent of 5/6Nx and augmented circulating triglycerides and predicted atherosclerosis signaling in 5/6Nx LV tissues. The changes are indicative of increased CV risk due to PD and highlight several pathways for potential therapeutic targets.

Prevalence of chronic periodontitis in patients undergoing peritoneal dialysis and its correlation with peritoneal dialysis-related complications

OBJECTIVE

The microinflammatory state can influence the occurrence of dialysis-related complications in dialysis patients. Chronic periodontitis (CP), in which plaque biofilm is considered to be the initiating factor, is a chronic infectious disease in the oral cavity. It is still uncertain whether CP affects the microinflammatory state in peritoneal dialysis (PD) and the occurrence of dialysis-related complications. The purpose of this study was to investigate the correlation between the periodontal index and clinical parameters in peritoneal dialysis patients with CP and dialysis-related complications, including peritoneal dialysis-associated peritonitis (PDAP) and cardiovascular and cerebrovascular events (CCEs).

METHODS

This was a retrospective cohort study, and 76 patients undergoing PD were enrolled. Clinical parameters, the occurrence of PD-related complications and periodontitis-related indicators, including the gingival index (GI), plaque index (PLI), probing depth (PPD) and clinical attachment loss (CAL), were collected. Correlation analysis was used to explore the correlation between periodontal or clinical parameters and the occurrence of PD-related complications.

RESULTS

All the patients had different degrees of periodontitis (mild 9.2%, moderate 72.4%, severe 18.4%); PPD was inversely related to serum albumin (r = - 0.235, p = 0.041); CAL has a positive correlation with serum C-reactive protein (rs = 0.242, p = 0.035); PLI was positively correlated with serum calcium (r = 0.314, p = 0.006). ANOVA, multivariate logistic regression analysis and Kaplan-Meier Survival curve suggested that CAL was a risk factor for the occurrence of PDAP. There was no correlation between periodontal parameters and CCEs or poor prognosis.

CONCLUSION

CP is universally present in PD patients, and the presentation of periodontitis influences the systemic inflammatory state in PD patients. CP is a risk factor for PDAP.

A nomogram predicts cardiovascular events in patients with peritoneal dialysis-associated peritonitis

Objective

To predict the risk factors for cardiovascular events within 5 years in patients with peritoneal dialysis-associated peritonitis and establish a nomogram for clinical prediction.

Methods

A prediction model was established by conducting an observational study in 150 patients with peritoneal dialysis-associated peritonitis obtained from the Information Database of AnHui Medical University Affiliated Hospital. The nomogram was constructed using the multivariate COX regression model. The C-index and the calibration plot were used to assess the discrimination and calibration of the prediction model.

Results

The elderly [HR = 2.453 (1.071–5.619)], history of cardiovascular events [HR = 2.296 (1.220–4.321)], alkaline phosphatase [HR = 1.004 (1.002–1.005)] and culture-positive [HR= 2.173 (1.009–4.682)] were identified as risk predictors of cardiovascular events, while serum albumin [HR = 0.396(0.170–0.924)] was identified as protective predictors of cardiovascular events. Combined with clinical studies, we constructed a nomogram based on the minimum value of the Akaike Information Criterion or Bayesian Information Criterion. The C index of the nomogram is 0.732, revealing great discrimination and appropriate calibration. Through the total score of the nomogram and the result of ROC, we classify patients into high-risk groups (cardiovascular events group) and low-risk groups (no cardiovascular events group). Cardiovascular events were significantly different for patients in the high-risk group compared to the low-risk group (HR = 3.862(2.202–6.772; p < 0.001).

Conclusions

The current novel nomogram can accurately predict cardiovascular events in patients with peritonitis associated with peritoneal dialysis. However, external validation is required before the model can be used in clinic settings.

Hypertriglyceridemia is a risk factor for treatment failure in patients with peritoneal dialysis-related peritonitis

OBJECTIVE

Disorders of triglycerides (TG) are common in patients with peritoneal dialysis (PD). Hypertriglyceridemia has been demonstrated in various infections. The association between triglycerides and the outcomes of peritoneal dialysis-related peritonitis (PDRP) was investigated in this study.

METHODS

We retrospectively investigated patients with PDRP from January 1, 2013 to October 31, 2020. Hypertriglyceridemia was defined as triglycerides ≥ 1.7 mmol/L. PDRP episodes were divided into two groups: hypertriglyceridemia and normal levels of triglycerides. The clinical and laboratory baseline data of the two groups were collected and compared. The association between triglycerides and treatment failure was analyzed by logistic regression analysis.

RESULTS

Ninety episodes in 66 patients were recorded in our center. Hypertriglyceridemia occurred in 38% (34/90) of episodes. Twenty-five episodes were not cured in 90 episodes (27.8%, 25/90). The levels of thrombocytes, high-sensitivity C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C) and glycated hemoglobin, were higher in hypertriglyceridemia episodes of PDRP at baseline. The bacterial classification was different between elevated triglyceride group and normal triglyceride group. Adjusted for age, duration of dialysis, residual renal function, diabetes, thrombocytes, hs-CRP, serum albumin, cholesterol, HDL-C, LDL-C, intact parathyroid hormone (iPTH), glycated hemoglobin and spectrum of bacteria, hypertriglyceridemia were associated significantly with treatment failure of PDRP in our study (OR 3.416, 95% CI 1.223-9.540 p < 0.05).

CONCLUSION

Hypertriglyceridemia at baseline was an independent risk factor for treatment failure of PDRP.