Urinary arsenic levels and risk of renal injury in a cross-sectional study in open population.

INTRODUCTION: Arsenic (As) is one of the most ubiquitous elements in nature, and a prolonged exposure has been associated with an increase in the risk of cancer, diabetes mellitus, hypertension and cardiovascular disease. There are few studies addressing the effects of As on albuminuria, tubular injury and biochemical variables as uric acid. AIM. To analyze the association between urinary As levels, albuminuria, and al-microglobulin as marker of tubular injury.
MATERIAL AND METHODS: This is a cross-sectional, and comparative study done in 5 communities localized close to Queretaro City. Subjects with no antecedents of renal disease, diabetes, hypertension, or industrial exposure to As were included. A questionnaire about risk factors for arsenic exposure was done, blood was taken for biochemical analysis and a spot urine sample was collected for albumin, alpha1-microglobulin, and As measurements.
RESULTS: A total of 90 adult persons were included with no antecedents of renal disease, diabetes or hypertension; the mean age was 40.9 +/- 12.9 years and the median for urinary As levels was 15 microg/gr Cr (range 0.56-89.2 microg/gr Cr), 10 (11.1%) persons had critical levels > 50 microg/gr Cr. Age more than 50 years old [OR 2.48 IC95 (0.9-6.6)] and place of residence were the most important risk factors associated with higher levels of As. There was association between urinary As levels and al-microglobulin urinary excretion (r2 = 0.07, p = 0.01) but not with albuminuria or other biochemical variables.
CONCLUSIONS: This is the first study in Mexico to show an association between As and urinary excretion of al-microglobulin as marker of early renal injury. We did not found association with albuminuria or other serum biochemical variables. Arsenic may be considered as a risk factor for tubular injury.