The Association Between Relative Fat Mass and Estimated Glomerular Filtration Rate in a Community-Dwelling Hypertensive Population

Background: Obese individuals are at elevated risk of chronic kidney disease (CKD), particularly in the presence of comorbid hypertension, but whether relative fat mass (RFM) can serve as an indicator of early renal dysfunction in hypertensive populations remains unclear. Among community-dwelling adults with hypertension in Jiangsu Province, China, we evaluated the relationship between RFM and estimated glomerular filtration rate (eGFR). Methods: We recruited 4439 adults with hypertension and defined reduced eGFR as <60 mL/min/1.73 m2. Multivariable logistic regression, subgroup analyses, restricted cubic spline (RCS) modeling, and receiver operating characteristic (ROC) curve analysis were used. Results: In total, 1474 participants (33%) had reduced eGFR. Each unit increase in RFM was marginally associated with higher odds of reduced eGFR after multivariable adjustment; adjusted odds increased across RFM quartiles and reached significance in Q3 and Q4. RCS analysis indicated an approximately linear association, and RFM yielded an area under the curve (AUC) of 0.630 for identifying reduced eGFR. Conclusions: Elevated RFM is independently associated with reduced eGFR in community-dwelling hypertensive adults, supporting its potential utility as a low-cost and readily accessible anthropometric marker for early screening of renal impairment in primary care.