Philip A. Clayton

Peritonitis is a major complication of peritoneal dialysis, but the relationship between peritonitis and mortality among these patients is not well understood. In this case-crossover study, we included the 1316 patients who received peritoneal dialysis in Australia and New Zealand from May 2004 through December 2009 and either died on peritoneal dialysis or within 30 days of transfer to hemodialysis. Each patient served as his or her own control. The mean age was 70 years, and the mean time receiving peritoneal dialysis was 3 years. In total, there were 1446 reported episodes of peritonitis with 27% of patients having ≥ 2 episodes. Compared with the rest of the year, there were significantly increased odds of peritonitis during the 120 days before death, although the magnitude of this association was much greater during the 30 days before death. Compared with a 30-day window 6 months before death, the odds for peritonitis was six-fold higher during the 30 days immediately before death (odds ratio, 6.2; 95% confidence interval, 4.4-8.7). In conclusion, peritonitis significantly associates with mortality in peritoneal dialysis patients. The increased odds extend up to 120 days after an episode of peritonitis but the magnitude is greater during the initial 30 days.

Significance Statement Given that the annual number of kidney transplants and the number of recipients living with a kidney transplant continue to rise, a contemporary assessment of trends in post-transplant mortality is urgently required. The authors’ analyses show that, despite changes in recipient profiles that confer increased risks of mortality, risks of death progressively declined over the past 40 years at all time points after transplantation, including after graft failure. Incidences of death from cardiovascular disease, cancer, and infection have all declined. Relatively greater reductions in cardiovascular death mean that cancer deaths now match cardiovascular deaths beyond the first post-transplant year in those with a functioning graft. This indicates that clinicians should focus on preventing death from cardiovascular disease and infections early post-transplant, and cancer and cardiovascular disease at later time points. Background Mortality risk after kidney transplantation can vary significantly during the post-transplant course. A contemporary assessment of trends in all-cause and cause-specific mortality at different periods post-transplant is required to better inform patients, clinicians, researchers, and policy makers. Methods We included all first kidney-only transplant recipients from 1980 through 2018 from the Australia and New Zealand Dialysis and Transplant Registry. We compared adjusted death rates per 5-year intervals, using a piecewise exponential survival model, stratified by time post-transplant or time post–graft failure. Results Of 23,210 recipients, 4765 died with a functioning graft. Risk of death declined over successive eras, at all periods post-transplant. Reductions in early deaths were most marked; however, recipients ≥10 years post-transplant were 20% less likely to die in the current era compared with preceding eras (2015–2018 versus 2005–2009, adjusted hazard ratio, 0.80; 95% confidence interval, 0.69 to 0.90). In 2015–2018, cardiovascular disease was the most common cause of death, particularly in months 0–3 post-transplant (1.18 per 100 patient-years). Cancer deaths were rare early post-transplant, but frequent at later time points (0.93 per 100 patient-years ≥10 years post-transplant). Among 3657 patients with first graft loss, 2472 died and were not retransplanted. Death was common in the first year after graft failure, and the cause was most commonly cardiovascular (50%). Conclusions Reductions in death early and late post-transplant over the past 40 years represent a major achievement. Reductions in cause-specific mortality at all time points post-transplant are also apparent. However, relatively greater reductions in cardiovascular death have increased the prominence of late cancer deaths.

Background: Obesity is a risk factor for cardiovascular disease and death in people without chronic kidney disease (CKD), but the effect of obesity in people with CKD is uncertain. Methods: Medline and Embase (from inception to January 2015) were searched for cohort studies measuring obesity by body mass index (BMI), waist:hip ratio (WHR) and/or waist circumference (WC) and all-cause and cardiovascular mortality or events in patients with any stage of CKD. Data were summarized using random effects models. Meta-regression was conducted to assess sources of heterogeneity. Results: Of 4065 potentially eligible citations, 165 studies ( n = 1 534 845 participants) were analyzed. In studies that found a nonlinear relationship, underweight people with CKD (3-5) on hemodialysis experienced an increased risk of death compared with those with normal weight. In transplant recipients, excess risk was observed at levels of morbid obesity (>35 kg/m 2 ). Of studies that found the relationship to be linear, a 1 kg/m 2 increase in BMI was associated with a 3 and 4% reduction in all-cause and cardiovascular mortality in patients on hemodialysis, respectively {adjusted hazard ratio [HR] 0.97 [95% confidence interval (CI) 0.96-0.98] and adjusted HR 0.96 (95% CI 0.92-1.00)}. In CKD Stages 3-5, for every 1 kg/m 2 increase in BMI there was a 1% reduction in all-cause mortality [HR 0.99 (95% CI 0.0.97-1.00)]. There was no apparent association between obesity and mortality in transplanted patients or those on peritoneal dialysis. Sparse data for WHR and WC did not allow further analyses. Conclusions: Being obese may be protective for all-cause mortality in the predialysis and hemodialysis populations, while being underweight suggests increased risk, but not in transplant recipients.