Increased Intestinal Hydrolysis of Urea in Patients with Alcoholic Cirrhosis

Abstract

Fourteen patients with biopsy-proven alcoholic liver cirrhosis in a clinically stable phase but with compromised liver function entered the study, together with 10 control persons. All had normal creatinine clearance, and none received antibiotics or hormones. They ingested a diet containing 1 g of protein/kg body weight daily during the study. The fractional intestinal loss of newly synthesized urea, determined by a ¹⁴C-urea tracer method, was increased from 0.17 ± 0.08 in controls to 0.26 ± 0.08 in cirrhotics (mean ± SD, P<0.02). Urea nitrogen synthesis rate, determined as urinary excretion rate, corrected for accumulation in the total body water and for fractional intestinal loss, was the same in controls and cirrhotics (26.1 ± 3.8 and 22.1 ± 6.8 mmol/h, respectively). The patients with cirrhosis had a significantly greater nitrogen balance than the control group (12.5 ± 7.0 mmol/h versus 7.0 ±5.9 mmol/h; P < 0.05). Furthermore, there was a positive correlation between intestinal loss and blood urea nitrogen concentration (r = 0.68, P < 0.01) in patients with cirrhosis but not in controls. The increased endogenous ammonia load of cirrhotics corresponds to an extra protein intake of 30-35 g/day. In patients with cirrhosis prophylactic treatment with, for example, lactulose is rational before reduction in dietary protein.

Key Words:

• Gut flora
• liver disease
• nitrogen conversion