By Peter Laird, MD
Exercise is one of the most important methods of improving outcomes in both the general population as well as in the dialysis population. Despite the claims that American dialysis patients are less healthy and more inactive than their Japanese, European and Australian counterparts, a recent study by DOPPS points out an excellent exercise participation by the majority of American dialysis patients:
RESULTS: Regular exercise frequency varied widely across countries and across dialysis facilities within a country. Overall, 47.4% of participants were categorized as regular exercisers. The odds of regular exercise was 38% higher for patients from facilities offering exercise programmes (adjusted odds ratio = 1.38 [95% confidence interval: 1.03-1.84]; P = 0.03). Regular exercisers had higher HRQoL, physical functioning and sleep quality scores; reported fewer limitations in physical activities; and were less bothered by bodily pain or lack of appetite.
Despite this excellent survey of American dialysis patients compared to their cohorts in other nations, exercise alone does not mitigate the other factors that attribute to our last place mortality compared to other nations:
Studies reported by DOPPS consistently show a marked difference in crude mortality between different countries, with the mortality in the United States being one of the highest. For example, in 2003, DOPPS reported the crude 1-yr mortality rates were 6.6% in Japan, 15.6% in Europe, and 21.7% in the United States. After adjustment for age, gender, race, and 25 comorbid conditions, including cardiovascular comorbidity, the relative risk (RR) for mortality was 2.84 for Europe compared with Japan and 3.78 for the United States compared with Japan. Thus, variability in demographic and comorbid conditions at dialysis inception explains only part of the variances in mortality between countries.
The recent study by DOPPS of the exercise habits among patients in different nations would not suggest a more sedentary population in the United States which is often one of the excuses many nephrologists juxtapose for these poor mortality outcomes. This study, while encouraging in the fact that most American dialysis patients do participate in frequent exercise, begs the question asked in the second article, why is the mortality of dialysis patients in the United States higher than the rest of the world?