Alcohol abuse: potential role in electrolyte disturbances and kidney diseases

The present review summarizes the current knowledge on the multiple effects of alcohol overconsumption on the kidney function as well as on water, electrolyte and acid-base homeostasis. In contrast to the well known transitory diuretic effects, the overall long-term effect of chronic alcohol overconsumption is water and salt retention with expansion of extracellular volume. Furthermore, depletion of magnesium, phosphate and calcium is also frequently found in alcohol-dependent patients. These electrolyte disturbances may be associated with the alcohol-induced hypoparathyroidism and parathyroid hormone resistance of the skeletal muscle as well as with the decrease of serum osteocalcin. Metabolic acidosis with lower arterial blood pH and plasma bicarbonate concentrations was revealed in alcoholic patients upon admission and a significant correlation between chronic alcohol overconsumption and increased incidence of hyperuricemia and gout attacks was also reported. Alcohol seems to have dual effects on the blood pressure. Increased blood pressure was demonstrated in men above 80 g and in women above 40 g ethanol consumption daily. In contrast, young adults consuming only 10 to 20 g per day had lower blood pressure than the abstinent group indicating a J-curve relationship. This is in line with the lowered risk for coronary heart disease associated with regular consumption of small alcohol amounts. The mechanisms responsible for the association between alcohol overconsumption and postinfectious glomerulonephritis have not been elucidated yet. Finally severe alcohol abuse predisposes to acute renal failure and seems to be associated with the general catabolic effects.