Rapid weight loss and gain correlate with increased risks for kidney failure, cardiovascular events, and death in patients with chronic kidney disease (CKD), a new study finds.
“Both weight gain and loss were independent risk factors for adverse outcomes,” Kook-Hwan Oh, MD, PhD, of Seoul National University College of Medicine in Seoul, Republic of Korea, and colleagues reported in the Journal of Renal Nutrition.
Using data from the KNOW-CKD study group, the investigators created weight trajectories for 2022 patients with CKD stages 1 to 5. They stratified patients into 5 categories based on the patients’ annual percent weight change: group 1, -5% or more; group 2, -5% to -2.5%; group 3, -2.5% to 2.5% (reference); group 4, 2.5% to 5%; and group 5, 5% or more. Weight gain or loss generally accelerated when estimated glomerular filtration rate (eGFR) declined to less than 30 mL/min/1.73 m2, possibly reflecting metabolic instability, the investigators noted.
Over a median 4.4 years, 414 patients progressed to end-stage kidney disease (ESKD) and 188 patients experienced a cardiovascular event or died. Cardiovascular events included acute myocardial infarction, unstable angina, percutaneous coronary artery intervention, coronary bypass graft surgery, ischemic or hemorrhagic stroke, congestive heart failure, symptomatic arrhythmia, or other major cardiovascular events requiring hospitalization, interventions, or therapy.
The investigators observed a U-shaped relationship between weight change over time and ESKD and the composite outcome of cardiovascular events or death. In adjusted analyses, groups 1 and 2 with rapid weight loss and groups 4 and 5 with rapid weight gain had a significant3.6-, 2.2-, 1.9-, and 3.7-fold increased risk for ESKD, respectively, compared with reference group 3. Groups 1, 2, and 5, had a significant 2.9-, 2.2, and 2.5-fold increased risk for the composite outcome of cardiovascular events and death, respectively. Group 4 had a nonsignificant 1.7-fold increased risk for the composite outcome. The strength of these associations was greater in patients with an eGFR less than 45 mL/min/1.73 m2.
Dr Oh’s team suggested several plausible mechanisms linking weight change and adverse outcomes, including protein energy wasting, decreased muscle to fat ratio, and edema from increased extracellular fluid volume. They could not determine whether the weight change was intentional or unintentional, which was a study limitation.
“The result of this study clearly showed that regular monitoring of weight change is crucial in patients with predialysis CKD and more research is needed to develop safe guidance for maintaining optimal nutrition,” the authors concluded.
Ryu H, Hong Y, Kang E, et al; KNOW-CKD study group. Rapid weight change over time is a risk factor for adverse outcomes in patients with predialysis chronic kidney disease: a prospective cohort study. Published online March 22, 2021. J Ren Nutr. doi:10.1053/j.jrn.2021.01.026