Association of Obesity With Kidney and Cardiac Outcomes Among Patients With Glomerular Disease: Findings From the Cure Glomerulonephropathy Network

Evan M Zeitler; Dorey A Glenn; Yichun Hu; Ronald J Falk; Susan L Hogan; Amy K Mottl; CureGN Investigators

doi:10.1053/j.ajkd.2024.03.020

Association of Obesity With Kidney and Cardiac Outcomes Among Patients With Glomerular Disease: Findings From the Cure Glomerulonephropathy Network

Am J Kidney Dis. 2024 May 13:S0272-6386(24)00756-X. doi: 10.1053/j.ajkd.2024.03.020. Online ahead of print.

Authors

Evan M Zeitler¹, Dorey A Glenn², Yichun Hu², Ronald J Falk², Susan L Hogan², Amy K Mottl²; CureGN Investigators

Collaborators

CureGN Investigators:
Ali Gharavi, Larry Greenbaum, Michelle Rheault, William E Smoyer, Ronald Falk, Lawrence B Holzman, Brenda Gillespie, Bruce Robinson, Laura Mariani, Cindy Roy, Lisa Guay-Woodford, Afshin Parsa

Affiliations

¹ Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: evan.zeitler@unchealth.unc.edu.
² Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

PMID: 38750877
DOI: 10.1053/j.ajkd.2024.03.020

Abstract

Rationale & objective: The influence of obesity on cardiorenal outcomes in individuals with glomerular disease is incompletely known. This study examined the association between obesity and kidney and cardiovascular outcomes in children and adults with glomerular kidney disease.

Study design: Prospective, multicenter, observational study.

Setting & participants: Participants in the Cure Glomerulonephropathy Network (CureGN) who were ≥5 years of age at enrollment.

Exposures: Adult body mass index (BMI) groups: 20-24 (healthy) vs 25-34 (overweight/class 1 obesity) vs ≥35 (class 2/3 obesity); and Pediatric BMI Percentiles: 5^th - 84^th (healthy) vs 85^th - 94^th (overweight) vs ≥95^th (obese).

Outcomes: A composite kidney outcome (40% eGFR decline or kidney failure) and a composite cardiovascular outcome (myocardial infarction, stroke, heart failure, or death) ANALYTICAL APPROACH: Time to composite primary outcomes by BMI strata were estimated using Kaplan-Meier analysis. The adjusted associations between BMI and outcomes were estimated using Cox proportional hazards analysis.

Results: The study included 2301 participants (1548 adults and 753 children). The incidence of the primary kidney endpoint was 90.8 per 1000 person-years in adults with class 2/3 obesity, compared with 58.0 in normal weight comparators. In the univariable analysis class 2/3 obesity was associated with the primary kidney outcome only in adults (HR 1.6, 95% CI 1.1-2.2, p = 0.006) compared to the healthy weight groups. In the multivariable adjusted analysis, class 2/3 obesity did not remain significant among adults when controlling for baseline eGFR and proteinuria. Adults with class 2/3 obesity had an incidence of 19.7 cardiovascular events per 1000 person-years, and greater cardiovascular risk (HR 3.9, 95%CI 1.4-10.7, p = 0.009) in the fully adjusted model.

Limitations: BMI is an imperfect indicator of adiposity. Residual confounding may exist from socioeconomic factors.

Conclusions: Among adult patients in CureGN, class 2/3 obesity is associated with cardiovascular but not kidney outcomes when adjusted for potential confounding factors.