Reversible tubular dysfunction in alcohol abuse

The discovery of an unexplained alkaline urine pH in a significant percentage of chronic alcoholic patients prompted us to evaluate some aspects of their tubular function. We studied 60 patients with a history of alcohol consumption of at least 160g daily for 10 years or more. Only patients without clinical and histopathological evidence of chronic liver disease were included in the study. The endogenous creatinine clearance was in the normal range in all patients. On the first day of hospitalisation 22 patients (36.6%) had a urine pH greater than 6.4 and a daily bicarbonate excretion ranging from 5.8 to 25.9mmol. The fractional urinary excretion of beta 2-microglobulin, sodium, potassium, chloride, calcium, phosphorus and uric acid were significantly increased compared with those of 38 alcoholic patients with urine pH less than 6.4 and those of 50 healthy controls. All these indices of tubular function improved during withdrawal, and after 30 days of abstinence their values did not differ from those of controls. This data provides evidence that in one-third of heavy drinkers alcohol abuse causes a complex tubular dysfunction which, at least in this stage of alcoholic disease, recovers with abstinence.