Prevalence of Protein-energy Wasting and Obesity Among Danish Dialysis Patients

Undernutrition among dialysis patients is associated with increased morbidity and mortality.

Conversely, in hemodialysis (HD) patients a high BMI in the range of obesity has long been known protective against death and cardiovascular disease, a phenomenon called reverse epidemiology. Hence, what is good for the background population might differ from what is good for HD patients.

In peritoneal dialysis (PD) patients this association is less clear. The majority of studies find reverse epidemiology, however some studies find no survival advantage of obesity or even indicate a higher risk of death in obese patients. Some authors claim that reverse epidemiology is a misconception and that although in the short run a high BMI is protective a follow up period of more than five years show increased mortality. Considering this Mutsert et al. claim that HD patients have the same mortality risk patterns associated with BMI as the general population.

Moreover, it has been shown that the protective effect of a high BMI or weight gain is limited to those with normal or high muscle mass. Patients with high BMI and malnutrition have a high risk of death. Concordantly, recent studies show that abdominal obesity is associated with mortality among dialysis patients .

The prevalence of under-nutrition, often known as protein energy wasting (PEW), among dialysis patients varies from 31% to 51% and the prevalence of obesity varies from 10-56% presumably depending on the diagnostic criteria and the method used. These inconsistent results make comparison of the prevalence of undernutrition and obesity among dialysis populations somewhat problematic.