Obese patients with chronic kidney disease (CKD) who have a rapid decline in body mass index (BMI) accompanied by a lesser increase in percent lean body mass and stable mean arterial pressure are at increased risk for death, according to study findings presented at the American Society of Nephrology’s Kidney Week 2022 meeting in Orlando, Florida.
The patients who exhibited this weight loss pattern likely had disproportionately higher losses of lean body mass than losses of fat mass, explained lead investigator Meera Nair Harhay, MD, of Drexel University College of Medicine in Philadelphia, Pennsylvania. Their ongoing excess adiposity might also explain why mean arterial pressure did not improve. These patients had a nearly 2-fold increased risk for death compared with individuals who exhibited a slower rate of weight loss, a steady increase in lean body mass percent, and a decrease in mean arterial pressure, according to investigators.
“Our study results suggest that patients with CKD and obesity should be counseled that extreme or rapid weight loss is risky, independent of their starting weight or BMI,” Dr Harhay told Renal & Urology News. “Our results also underscore the importance of maintaining or increasing lean body mass during weight loss. Assessments of lean body mass and hemodynamic trajectories might help clinicians support their patients with obesity and CKD to safely achieve their weight loss goals.”
The study include 2909 participants in the Chronic Renal Insufficiency Cohort (CRIC) study. They had a median age of 61 years, median baseline BMI of 35.5 kg/m2, and median follow-up of 6.4 years. Of these patients, 82% were trying to lose weight.
“It might seem intuitive that not all weight loss is created equal,” Dr Harhay said. “However, we often use terms like ‘healthy weight loss’ without a clear definition for exactly what that means. Adults with obesity and CKD are often strongly encouraged or even required to lose weight to improve their health or become eligible for transplant. We studied this topic to be able to better identify characteristics of healthy weight loss and risky weight loss in this population.”
Previous research has demonstrated an association between weight loss and adverse outcomes in patients with CKD. For example, a study by Elaine Ku, MD, of the University of California, San Francisco, and colleagues, which was published in 2018 in the American Journal of Kidney Diseases, found that among patients with advanced CKD, a more than 5% annualized weight loss after estimated glomerular filtration rate decreased to less than 35 mL/min/1.73 m2 was associated with a 54% higher mortality risk after dialysis initiation.
In a 2021 article in the Journal of Renal of Nutrition, investigators in South Korea reported findings from a prospective cohort study showing that both rapid weight loss and weight gain increase the risk for end-stage kidney disease and a composite of cardiovascular disease and death among patients with CKD. The increased risk was particularly pronounced in patients with advanced CKD.
Harhay MN, Robinson L, Yuna K, Milliron, BJ. Obesity weight loss phenotypes in CKD: Data from the Chronic Renal Insufficiency Cohort Study (CRIC). Presented at: Kidney Week 2022; November 3-6, Orlando, Florida. Abstract SA-OR40.
Ku E, Kopple JD, Johansen KL, et al. Longitudinal weight change during CKD progression and its association with subsequent mortality. Am J Kidney Dis. 2018;71(5):657-665. doi:10.1053/j.ajkd.2017.09.015
Ryu H, Hong Y, Kang E, et al. Rapid weight change over time is a risk factor for adverse outcomes in patients with predialysis chronic kidney disease: A prospective cohort study. J Ren Nutr. 2021;31(6):569-578. doi:10.1053/j.jrn.2021.01.026