Among patients with mild to moderate chronic kidney disease (CKD), those who report low health-related quality of life have higher risks of cardiovascular (CV) events as well as death, a new study finds.
Previous research revealed that greater risks exist for end-stage renal disease (ESRD) patients, so a team led by Anna C. Porter, MD, of the University of Illinois at Chicago, studied pre-dialysis CKD patients. They examined data from 3,837 participants with CKD stages 2–4 from the Chronic Renal Insufficiency Cohort (CRIC) and Hispanic Chronic Renal Insufficiency Cohort (H-CRIC), robust and ethnically diverse prospective studies.
Health-related quality of life (HRQoL) at baseline was measured via the Kidney Disease and Quality of Life (KDQOL-36) questionnaire, which gauges kidney disease-specific domains. The 5 subscales include a mental component summary (e.g., depression and anxiety, energy level, and social activities); physical component summary; burden of kidney disease (e.g., the degree to which fluid or diet restrictions are taxing); effects of kidney disease (how CKD interferes with daily life); and symptoms and problems of kidney disease (e.g., lack of appetite and shortness of breath).
The primary outcomes were CKD progression (defined as a 50% decline from baseline in estimated glomerular filtration rate [eGFR] or ESRD); cardiovascular events (myocardial infarction, stroke, heart failure, atrial fibrillation, or revascularization procedure for peripheral arterial disease); and all-cause mortality.
The investigators found that both sociodemographic and clinical factors were associated with low HRQoL at baseline. Patients of younger age, low education, and female gender reported worse quality of life on KDQOL-36. Those with diabetes, vascular disease, congestive heart failure, obesity, and lower eGFR also complained of low HRQoL.
During a median follow-up of 6.2 years, the researchers observed higher crude rates of all outcomes across all 5 subscales. In fully adjusted models, however, low scores on 3 subscales—physical component summary, effects, and symptoms—were tied with higher risk of CV events and death. Low scores on the mental component summary were linked with higher risk of death only.
“Collectively, these findings underscore the importance of heightened attention to HRQoL in patients with low socioeconomic status, certain comorbid diseases, and more advanced CKD,” Dr Porter and colleagues wrote in the Clinical Journal of the American Society of Nephrology.
The investigators speculated that poor scores on mental health may reflect unhealthy lifestyle choices, such as smoking or medication noncompliance, which might contribute to mortality. Likewise, physical inactivity might be partly to blame for CV events and death.
A better understanding of the mechanisms linking HRQoL and these outcomes is important, added Neil R. Powe, MD, of Zuckerberg San Francisco General Hospital, in an accompanying editorial. “The clinical implications of this study are central to improving care,” Dr. Powe wrote. “Given the prevalence of CKD, decrements in HRQoL, and consequences of poor HRQoL in patients with CKD, we need to learn how to best communicate to patients how HRQoL affects prognosis and more importantly, what we can do or tell them to prevent poor outcomes.”