While BMI identified obesity in 38.9% of study participants, nearly 64% met clinical criteria when using waist circumference and waist-to-height ratios.
BMI Fails to Account for Body Composition
- The BMI Gap: BMI calculates weight relative to height but fails to account for body composition.
Clinical Discrepancies in the OBERCE Project
The OBERCE project, presented at the 56th Congress of the Spanish Society of Nephrology (SEN), examined 2,036 adults with CKD across 20 Spanish hospitals between February and August 2025.
The findings show a wide gender disparity. Women in the study were more likely to present with clinical obesity, yet they were prescribed renoprotective medications—such as ACE inhibitors, ARBs, and SGLT2 inhibitors—less frequently than their male counterparts. These women also exhibited a lower estimated glomerular filtration rate (eGFR) of 36 ml/min/1.73m² compared to 40 ml/min/1.73m² in men, indicating a more advanced state of renal functional decline.
CKD Could Become Fifth Leading Cause
Chronic kidney disease is increasingly recognized as a silent epidemic. According to reports from La Opinión de Murcia and La Verdad, approximately 15% of the Spanish population lives with some form of CKD, totaling nearly seven million people.
The clinical consequences are severe. Emilio Sánchez, of the SEN, warned that if current growth rates persist without improved screening and early intervention, CKD could become the fifth leading cause of death in Spain by 2040, with one-third of the population over 65 affected.
| Metric | BMI-Based Detection | Waist/Height-Based Detection |
|---|---|---|
| Obesity Prevalence (CKD Patients) | 38.9% | 63.5% |
| “Hidden Obesity” (Normal BMI) | 0% (by definition) | 27.4% |
| GLP-1 Receptor Agonist Access | Restricted by BMI >30 | Often denied due to low BMI |
Clinical Intervention for Visceral Fat
Relying solely on BMI can provide a false sense of security. Clinical intervention is generally recommended when waist circumference measurements exceed established healthy thresholds, as visceral fat is metabolically active and directly exacerbates renal inflammation.
Those currently prescribed GLP-1 receptor agonists or SGLT2 inhibitors should continue their regimen under professional supervision.
Future Trajectory of Nephrological Care
The 56th SEN Congress, running through November 7, 2026, serves as a platform for integrating precision medicine into standard practice. As nephrologists move to adopt tools like cystatin C as a more accurate marker of renal function and incorporate artificial intelligence for early detection, the goal is to shift from reactive dialysis-based care to proactive, preventative management. For millions, the “silent” nature of the disease remains the primary obstacle, but improved diagnostic criteria for obesity are a necessary step toward the long-term goal of stabilizing renal function across the population.
