RENAL TUBULAR DYSFUNCTION IN CHRONIC ALCOHOL-ABUSE - EFFECTS OF ABSTINENCE

Background. Alcohol abuse may be accompanied by a variety of disorders of electrolyte and acid-base metabolism. The role of the kidney in th e pathogenesis of these disturbances is obscure. We sought to evaluate the alcohol-induced abnormalities of renal function and improvement d uring abstinence and to assess the relation between renal dysfunction and electrolyte and acid-base disorders.Methods. We measured biochemic al constituents of blood and renal function before and after four week s of abstinence in 61 patients with chronic alcoholism who had little or no liver disease. Results. On admission, 18 patients (30 percent) h ad hypophosphatemia and hypomagnesemia, 13 patients (21 percent) had h ypocalcemia, and 8 patients (13 percent) had hypokalemia. Twenty-two p atients (36 percent) had a variety of simple and mixed acid-base disor ders. Twenty of these patients had metabolic acidosis, and among them, 80 percent had alcoholic acidosis. A wide range of defects in renal t ubular function, with normal glomerular filtration rate, was detected in these patients. The defects included decreases in the threshold and maximal reabsorptive ability for glucose (38 percent of patients) and in the renal threshold for phosphate excretion (36 percent); increase s in the fractional excretion of beta2-microglobulin (38 percent), uri c acid (12 percent), calcium (23 percent), and magnesium (21 percent); and aminoaciduria (38 percent). Seventeen patients (28 percent) had a defect in tubular acidification, and five an impairment in urinary co ncentrating ability. Urinary excretion of N-acetyl-beta-D-glucosaminid ase and alanine aminopeptidase was increased in 41 and 34 percent of p atients, respectively. The abnormalities of blood chemistry and renal tubular function disappeared after four weeks of abstinence. Conclusio ns. Transient defects in renal tubular function are common in patients with chronic alcoholism and may contribute to their abnormalities of serum electrolyte and blood acid-base profiles.