Assessment of Heavy Metal Exposure in Adult Patients with Minimal Change Disease: A Cross-sectional Case-Control Study.

Abstract

Background: Minimal change disease (MCD) is a major cause of nephrotic syndrome and is traditionally considered an immune-mediated podocytopathy. Environmental heavy metals have emerged as potential nephrotoxic factors that may contribute to glomerular injury and disease susceptibility.

Objectives: The objectives of this study were to determine serum concentrations of selected heavy metals and evaluate their association with MCD in adults.

Materials and methods: This cross-sectional case-control study was conducted in the Department of Nephrology at a tertiary care teaching hospital between October 2024 and December 2025. Twenty adults with biopsy-proven MCD and 20 age- and sex-matched healthy controls were enrolled. Clinical, environmental, and occupational exposure histories were recorded. Serum concentrations of chromium, cadmium, arsenic, lead, and mercury were measured using inductively coupled plasma mass spectrometry. Heavy metal levels were compared between cases and controls and correlated with clinical parameters including serum albumin, urine protein-creatinine ratio, and acute kidney injury (AKI).

Results: The mean age of MCD patients was 31.6 ± 12.4 years, with males constituting 70% of cases. Severe albuminuria and nephrotic-range proteinuria were present in 85% of patients, while severe hypoalbuminemia was observed in 75%. AKI occurred in 35% of cases. Mean serum chromium (3.80 ± 1.42 vs. 1.80 ± 0.52 μg/L; P < 0.001) and cadmium levels (0.58 ± 0.56 vs. 0.00 ± 0.00 μg/L; P < 0.001) were significantly higher among MCD patients compared with controls. Elevated chromium levels were detected in 95% of cases, arsenic in 75%, cadmium in 20%, and lead in 10%, whereas mercury was undetectable in all participants. No significant associations were observed between heavy metal concentrations and serum albumin levels, proteinuria severity, or AKI (P > 0.05). Steroid sensitivity and complete remission were achieved in 90% of patients.

Conclusions: Adult patients with MCD demonstrated significantly higher serum chromium and cadmium concentrations compared with healthy controls. However, heavy metal exposure was not associated with disease severity or renal outcomes. These findings suggest that environmental heavy metals may act as contributory factors rather than direct determinants of disease expression. Larger prospective studies are required to clarify the role of environmental nephrotoxins in the pathogenesis of MCD.