Asymptomatic Renal Function Abnormalities in Patients having Silicosis

A number of occupational exposures are associated with various types of renal dysfunction. Several studies for many years have drawn attention to renal dysfunction and nephrotoxicity among workers exposed to silica. This study was conducted to evaluate renal dysfunction, if any, among Indian patients having silicosis and its correlation with the duration of exposure to silica dust.

This study includes 52 eligible patients with a history of silica dust exposure and silicosis confirm on radiological examination by the pneumoconiosis board. Investigations like serum creatinine, urinary albumin creatinine ratio, etc. were done. The "modification of diet in renal disease" (MDRD) formula was used to calculate the glomerular filtration rate (GFR).

This study showed 53.84% of patients (n = 28) having albuminuria and a mean "urinary albumin to creatinine ratio" (UACR) of 101.88 ± 128.99 mg/gm. Isolated macroalbuminuria was detected in 11.5% of patients (n = 6) while 42.3% of patients (n = 22) presented with microalbuminuria. The mean GFR was 81.94 ± 22.09 mL/min/1.73 m2 among study patients of which four (7.7%) patients had GFR value <60 mL/min/1.73 m2 . We could also identify a significant association between the duration of exposure to silica dust and UACR and GFR (p < 0.01).

Albuminuria and reduced estimated GFR in patients with silica dust exposure is not uncommon and reflect early underlying renal dysfunctions. Our study suggests a simple and cost-effective screening strategy for early detection of renal dysfunction among silicosis patients that may be considered as a tool to prevent further renal damage in such patients.