Effect of uric acid levels on mortality in Japanese peritoneal dialysis patients

Abstract

Background: Unlike the situation in the general population, most studies of patients receiving hemodialysis have reported lower uric acid (UA) as associated with higher mortality. However, the relationship between UA level and mortality remains unclear among patients receiving peritoneal dialysis (PD). Methods: We collected baseline data for 4742 prevalent PD patients (age, 63 ± 14 years; male, 61.5%; diabetes, 29.1%; median dialysis duration, 28 months) from a nationwide dialysis registry in Japan at the end of 2012. One-year all-cause and cardiovascular (CV) mortality and mortality caused by infectious disease were assessed using Cox regression analysis and competing-risks regression analysis, respectively. We used multiple imputation to deal with missing covariate data. Results: Within 1 year, 379 patients (8.0%) died, including 129 patients (2.7%) from CV causes and 95 patients (2.0%) from infectious disease. In multivariate analysis, serum UA, treated as a continuous variable, was not associated with any outcome. Conversely, both lower (<297 µmol/L) and higher (≥476 µmol/L) UA levels were independently associated with higher all-cause mortality compared to the reference group (416 to <446 µmol/L) in analyses where serum UA was treated as a categorical variable. Body mass index (BMI) affected the association between serum UA and all-cause mortality (interaction p = 0.049). Conclusions: A U-shaped relationship appears to exist between UA levels and all-cause mortality among Japanese PD patients. Additionally, lower BMI significantly enhanced the effect of UA levels on mortality.

The prognosis and risk factors of baseline high peritoneal transporters on patients with peritoneal dialysis

“…The DOPPS study (a large ongoing international prospective cohort study of 4637 haemodialysis patients [median follow‐up, 23 months]) concluded that baseline serum uric acid level was reversely and independently related to all‐cause and CV mortality, and it was explained in part that higher levels of serum UA were a marker for better nutritional status 62 . As for peritoneal dialysis, several studies revealed a ‘U‐shaped’ relationship between UA levels and all‐cause mortality 63,64 . Lower serum UA levels had been identified as reflecting deteriorated intake of nutrition including protein and calorie.…”

“…Even so, we had not reached a similar conclusion about SUA, as one of the nutrition indicators and traditional CVD risk factors as well, and we found an inverse relationship between total cholesterol and all‐cause mortality. Malnutrition‐related hypocholesterolaemia often increases mortality in patients received dialysis 63,65 . Arsalan et al suggested PD patients with TC levels ≤125 mg/dl (3.24 mM) had a statistically significant increased risk of an all‐cause mortality 65 .…”

“… 62 As for peritoneal dialysis, several studies revealed a ‘U‐shaped’ relationship between UA levels and all‐cause mortality. 63 , 64 Lower serum UA levels had been identified as reflecting deteriorated intake of nutrition including protein and calorie. Even so, we had not reached a similar conclusion about SUA, as one of the nutrition indicators and traditional CVD risk factors as well, and we found an inverse relationship between total cholesterol and all‐cause mortality.…”

Association between serum elastin-derived peptides and abdominal aortic calcification in peritoneal dialysis patients: a cross-sectional study

“…Consistently, Lai et al also found higher SUA was associated with lower cardiovascular and all-cause mortality in 492 PD patients [ 38 ]. While a U-shaped relationship between UA and all-cause mortality was found in a nationwide cohort study in Japan [ 39 ]. The role of UA in vascular calcification in PD patients seemed to be controversial and needs further investigation.…”

Relationship between serum uric acid and all-cause mortality in dialysis patients: like being in wonderland, disoriented

“…Finally, An observational study by Sugano et al [4]. using a large-scale registry of 4742 Japanese PD patients revealed a U-shaped relationship between UA levels and all-cause mortality.…”