Weight Change Correlates with Adverse Outcomes in CKD

Both obesity and being underweight put patients with chronic kidney disease (CKD) at risk for adverse outcomes. However, according to Hyunjin Ryu, MD, MS, and colleagues, there are few data available of the effect of longitudinal weight changes in patients with predialysis CKD. The researchers conducted an analysis to examine the effects of weight change over time on adverse outcomes in patients with non-dialysis CKD. Results were reported in the Journal of Renal Nutrition [2021;31(6):569-578].

The analysis included longitudinal data from KNOW-CKD, a multicenter prospective cohort study. In a cohort of 2022 patients, the percent weight change per year was calculated using regression analysis. Study participants were classified into five categories: group 1, ≤–5% per year; group 2, –5 to ≤–2.5% per year; group 3, –2.5< to <2.5% per year; group 4, ≤2.5 to <5% per year; and group 5, ≥5% per year. Incidence of end-stage kidney disease (ESKD) and the composite outcome of cardiovascular disease and death were calculated in each group and compared to group 3 as reference.

Median follow-up was 4.4 years. During that time, there were 414 ESKD and 188 composite of cardiovascular disease and mortality events. Independent risk factors for adverse events included both weight gain and weight loss. There was a U-shaped correlation between the degree of longitudinal weight change and ESKD (hazard ratios for group 1, 2, 4, and 5 were 3.61, 2.15, 1.86, and 3.66, respectively) and for the composite of cardiovascular disease and death (hazard ratios, 2.92, 2.15, 1.73, and 2.54, respectively) when compared with the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m².

“Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in advanced CKD,” the authors summarized.