Histopathological Features and Clinical Implications of Obesity-Associated Glomerulopathy in Children

Abstract

Background: Childhood obesity has emerged as a major public health concern worldwide and is increasingly associated with obesity-associated glomerulopathy (OAG), a renal disorder characterized by glomerular hypertrophy, focal segmental glomerulosclerosis (FSGS), proteinuria, and progressive decline in renal function. Early detection of obesity-related renal injury is crucial to preventing progression to chronic kidney disease (CKD).

Objective: To evaluate the histopathological features and clinical implications of obesity-associated glomerulopathy among obese pediatric patients presenting to tertiary care hospitals in Islamabad, Pakistan.

Methods: A cross-sectional study was conducted at tertiary healthcare centers in Lahore and Hyderabad, Pakistan, from January 2023 to December 2025. A total of 120 obese children aged 6–16 years with persistent proteinuria were enrolled. Clinical assessment included body mass index (BMI), blood pressure, serum creatinine, estimated glomerular filtration rate (eGFR), urinary protein excretion, lipid profile, and fasting blood glucose levels. Renal biopsy was performed in patients with persistent proteinuria (>1 g/day) and/or declining renal function. Histopathological evaluation was carried out using light microscopy and immunofluorescence techniques.

Results: The mean age of participants was 11.8 ± 2.7 years, and 61.7% (n = 74) were male. The mean BMI was 31.4 ± 3.8 kg/m². Proteinuria was present in 78.3% of participants, while hypertension was identified in 34.2%. Renal biopsy was performed in 42 patients. Histopathological examination revealed glomerulomegaly in 83.3%, podocyte hypertrophy in 57.1%, focal segmental glomerulosclerosis in 45.2%, and mesangial expansion in 38.1% of biopsy specimens. The mean urinary protein excretion among biopsy-positive patients was 1.82 ± 0.64 g/day. BMI demonstrated a significant positive correlation with the degree of proteinuria (r = 0.49, p < 0.001). Patients with FSGS exhibited significantly lower eGFR values compared with those without FSGS (89.4 ± 12.6 vs. 104.8 ± 14.3 mL/min/1.73 m², p = 0.002).

Conclusion: Obesity-associated glomerulopathy is an emerging cause of renal injury in Pakistani children. Glomerulomegaly and secondary FSGS were the predominant histopathological findings and were significantly associated with increased proteinuria and reduced renal function. Early screening, lifestyle modification, and timely intervention may help mitigate progression to chronic kidney disease and reduce the long-term burden of obesity-related renal complications.