BACKGROUND Worsening cirrhosis may lead to increased renal O₂ metabolism caused by activation of neurohumoral antinatriuretic substances.

AIMS To evaluate the relation between the severity of liver disease, sodium excretion, and neurohumoral antinatriuretic substances on the one hand and renal O₂ metabolism on the other in patients with cirrhosis.

RESULTS Renal O₂ consumption significantly increased with the severity of cirrhosis (grade A, 8.9 (1.6); grade B, 15.5 (1.3); grade C, 18.0 (1.5) ml/min/m²). Plasma concentrations of noradrenaline, renin, and aldosterone significantly increased while mean arterial presssure and systemic vascular resistance significantly decreased with the severity of the disease. A significant inverse correlation was found between renal O₂ consumption and sodium excretion. A significant direct correlation was found between plasma levels of noradrenaline and aldosterone on the one hand and renal O₂consumption on the other. Renal blood flow and the glomerular filtration rate did not differ significantly between patients with grade C and grade A or B disease.

CONCLUSIONS This study shows for the first time that, in patients with cirrhosis, worsening of the disease is associated with an increase in renal O₂consumption. The results suggest that increased renal O₂consumption is due to renal tubular sodium retention caused by increased levels of neurohumoral antinatriuretic substances. This neurohumoral activation is related to cirrhosis induced vasodilation.