Effect of renal tubular damage on non-cancer mortality in the general Japanese population living in cadmium non-polluted areas.

ABSTRACT

This study aimed to clarify the cause-effect relationship between renal tubular damage and non-cancer mortality in the general Japanese population. We conducted a 19-year cohort study including 1110 men and 1,03 women who lived in three cadmium-non-polluted areas in 1993 or 1994. Mortality risk ratios based on urinary ß2-microglobulin (ß2MG) and N-acetyl-ß-glucosaminidase (NAG) concentrations were estimated for specific non-cancer diseases using the Fine and Gray competing risks regression model. In men, continuous urinary NAG (+1 µg/g cre) concentrations were significantly correlated with increased mortality caused by diseases of the respiratory system (hazard ratio (HR) 1.09, 95% confidence interval (CI) 1.03-1.15). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortalities caused by kidney and urinary tract diseases (HR 1.01, 95% CI 1.00-1.03), renal diseases (HR 1.01, 95% CI 1.00-1.03), renal failure (HR 1.02, 95% CI 1.00-1.03), and external causes of mortality (HR 1.01, 95% CI 1.00-1.02). In women, urinary NAG (+1 µg/g cre) concentrations were significantly associated with increased mortality caused by ischemic heart diseases (HR 1.02, 95% CI 1.00-1.04) and kidney and urinary tract diseases (HR 1.01, 95% CI 1.00-1.04). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortality caused by cardiovascular diseases (HR 1.01, 95%CI 1.00-1.02), ischemic heart diseases (HR 1.01, 95%CI 1.00-1.02), and kidney and urinary tract diseases (HR 1.02, 95% CI 1.01-1.03). The present study indicates that renal tubular damage was significantly related to several non-cancer disease causes of mortality in Japan's general population living in cadmium-non-polluted areas.