Association of Body Mass Index and Comorbidities with Chronic Kidney Disease Severity: A Prospective Observational Study

Abstract

Background: Chronic Kidney Disease (CKD) is a progressive disorder characterized by irreversible deterioration of kidney function and is associated with substantial morbidity and mortality worldwide. Obesity and chronic comorbid conditions, particularly hypertension and diabetes mellitus, are recognized as major contributors to CKD development and progression. Understanding their relationship with disease severity is essential for improving preventive and therapeutic strategies. Objective: To evaluate the association between body mass index (BMI), comorbidities, and the severity of chronic kidney disease among patients attending a tertiary care nephrology center. Methods: A prospective observational study was conducted in the Department of Nephrology at Muljibhai Patel Urological Hospital, Nadiad, Gujarat, India, between September 2024 and January 2025. A total of 380 adult patients diagnosed with CKD stages 1–5 were enrolled. CKD staging was performed according to the kidney disease: Improving Global Outcomes (KDIGO) guidelines. Body mass index was classified using World Health Organization criteria. Demographic characteristics, CKD stage, BMI, dialysis status, and associated comorbidities were recorded. Descriptive statistics and the Chi-square test were used for data analysis, with a p-value of <0.05 considered statistically significant. Results: Among the 380 patients, Stage 5 CKD constituted the largest proportion (54.2%), followed by Stage 4 (19.2%). Most patients had a normal BMI (50.3%), while 28.4% were overweight and 11.1% were underweight. Hypertension combined with diabetes mellitus was the most prevalent comorbidity (26.6%), followed by hypertension alone (25.0%). Advanced CKD stages were associated with a higher prevalence of multiple comorbidities and greater nutritional abnormalities. Conclusion: Body mass index and comorbidity burden are closely associated with CKD severity. The high prevalence of hypertension and diabetes mellitus among patients with advanced CKD highlights the importance of early screening, weight management, and comprehensive control of associated comorbidities to delay disease progression and improve clinical outcomes.