Abnormalities of renal function in the elderly.
OBJECTIVE
To investigate the glomerular and proximal tubular renal function and the prevalence of urinary abnormalities in the elderly.


METHODS
Cross-sectional study.


METHODS
General community in the city of São Paulo.


METHODS
A population-based sample of 200 elderly subjects was randomly selected. Of these, 81 subjects (45 females and 36 males; mean +/- SD age: 73.7 +/- 6 years) accepted to undergo laboratory examination and were included in the study.


METHODS
24-h creatinine clearance (CCr), microalbuminuria, urinary retinol-binding protein (urRBP), leukocyturia, hematuria and total proteinuria.


RESULTS
CCr was lower than 80 ml/min/1.73 m2 in 68% of the subjects. The median (range) CCr was 65 ml/min/1.73 m2 (21-112) in males and 77 ml/min/1.73 m2 (27-107) in females (p = 0.14). No individual had serum creatinine greater than 1.5 mg/dl. urRBP determination was normal in 79 of 81 subjects. The prevalence of microalbuminuria (> 20 micrograms/ml) was 31% (n = 25, 19 men and 6 women). These individuals presented higher mean systolic blood pressure (147 +/- 20 vs. 135 +/- 22 mmHg, p = 0.02) and mean serum creatinine (1.13 +/- 0.20 vs. 0.96 +/- 0.20 mg/dl, p < 0.01) than those without microalbuminuria. The prevalence of leukocyturia (> 10,000/mm3), hematuria (> 10,000/mm3) and total proteinuria (> or = 0.3 mg/dl) was 19%, 28% and 5% in males and 33%, 27% and 4% in females.


CONCLUSIONS
Glomerular dysfunction and urinary abnormalities are frequent features in the elderly, however, proximal tubular dysfunction is uncommon in this population.
Abreu
P F
PF
Division of Nephrology, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil.
Ramos
L R
LR
Sesso
R
R
D000368:Aged; D000375:Aging / Q000502:physiology*; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007678:Kidney Glomerulus / Q000378:metabolism / Q000503:physiopathology*; D007684:Kidney Tubules / Q000378:metabolism / Q000503:physiopathology*; D008297:Male
D003404:Creatinine