Preventing Progression of Renal Disease: A New Method for Monitoring Body Fat Percentage in Predialysis Chronic Kidney Disease Patients

•Developed a noninvasive method to estimate body fat percentage in CKD patients.•New model avoids the need for bioimpedance and simplifies nutritional assessment.•Method validated with high explanatory power and strong statistical associations.•Practical for resource-limited settings, improving CKD patient management.•Findings support improved patient outcomes through better nutritional assessment. Chronic kidney disease (CKD) is a progressive condition affecting metabolic pathways and physiological mechanisms. In Spain, CKD prevalence has risen, increasing patients requiring renal replacement therapy (RRT). Managing nutritional status in advanced CKD (ACKD) patients is crucial as it influences disease progression and quality of life. This study aims to describe the nutritional status of predialysis patients at University Hospital Reina Sofia, Cordoba, Spain, and develop a quick and easy model for estimating body fat percentage without bioimpedance. This cross-sectional study, conducted from February to May 2023, involved 106 patients from the ACKD consultation at the University Hospital Reina Sofia. Inclusion criteria were stage 3 or 4 CKD patients who consented to participate. Data included demographic and anthropometric variables, with body composition assessed using a Tanita BC-545N bioimpedance analyzer. The sample included 32 females (30.5%) and 73 males (69.5%), with an average BMI of 30.31 (SD 5.48). Significant findings were higher body fat percentage in women (37.82%) than men (27.86%; P < 0.001) and notable differences in waist circumference and waist-to-hip ratio between sexes. Multiple linear regression showed waist circumference, height, and sex as significant predictors of body fat percentage, with an intraclass correlation coefficient of 0.71 (95% CI = 0.59–0.79). Accurately assessing body composition in CKD patients is crucial as traditional measures like BMI may not capture health risks effectively. The developed model offers a practical alternative to bioimpedance for estimating body fat percentage, potentially improving CKD management and patient outcomes. Further validation in diverse populations and integration with lifestyle interventions is needed.