Prevalence of proteinuria in rural adult population in Tamil Nadu.

BACKGROUND & OBJECTIVES Presence of proteinuria is considered as an early marker of an increased risk of progressive kidney disease. Angiotensin converting enzyme (ACE) inhibitors (ACEi) and angiotensin II receptor blockers (ARB) treatment to persons with proteinuria and chronic kidney disease has been shown to decrease the progression to endstage renal disease. As the exact prevalence of proteinuria is not known in the general population, we undertook this study to estimate the same in a rural adult population in Vellore district, Tamil Nadu. METHODS A convenient sample of 5,043 adults was included. All individuals were tested for albuminuria by albumin dipstick examination in an untimed urine sample. Individuals who tested positive for albuminuria underwent a second dipstick examination after a gap of one week. Individuals with persistent albuminuria on the second dipstick examination underwent further evaluation which included medical history, physical examination, 24 h urine protein estimation, total serum protein and albumin estimation. Ultrasound of the abdomen was done in patients with renal failure and renal biopsy was performed in selected patients. RESULTS Of the total 5,043 individuals screened, 63.1 per cent were females. Mean age of the study population was 50.94 +/- 11.2 yr. First dipstick test identified 594 individuals positive for albuminuria. Repeat dipstick could be done in only 576, of whom 212 showed persistent albuminuria. Significant proteinuria was detected in 24 individuals of the 208 who had 24 h urine protein measured. Of these 24 patients, 3 were found to have chronic renal failure, 12 were presumed to have diabetic nephropathy clinically, one each had focal segmental glomerulosclerosis and biopsy proven diabetic nephropathy, and 7 patients had proteinuria of unknown aetiology. INTERPRETATION & CONCLUSION The prevalence of proteinuria in this adult rural population was 0.47 per cent (0.30-0.67%). The detection and treatment of chronic kidney disease in 24 individuals is bound to reduce the rate of decline of renal functions. Screening programme for proteinuria in different parts of country may be an effective measure to bring a decline in rate of progression of chronic kidney disease in general population.