['An increased ammonia level of gut bacterial origin is an important mediator in the pathogenesis of hepatic encephalopathy (HE), and constipation is a frequent precipitant of hepatic coma. Because diabetes mellitus (DM) may be associated with delayed gastrointestinal transit, we speculated that its presence in patients with HCV-related cirrhosis would predispose to and exacerbate HE.', 'Sixty-five patients (50 men, 15 women) with HCV-related cirrhosis attending a liver transplantation clinic were assessed for severity of liver disease and presence of DM in a cross-sectional study. A modified Child-Pugh score that excluded HE was calculated. Frequency and severity of HE (absent, mild, and severe) in diabetic and nondiabetic patients were assessed. Clinical severity of cirrhosis and results of neuropsychometric testing in diabetic and nondiabetic patients with mild and severe HE were compared.', 'Fifty-four patients (83%) had HE (33 mild, 21 severe). Twenty patients (31%) had DM. HE was present in 19 (95%) patients with diabetes and 35 (78%) patients without diabetes (p = 0.087). Severity of HE was greater in diabetic (35% mild, 60% severe) than in nondiabetic patients (58% mild, 20% severe) (p = 0.007). In both the mild and severe HE categories, severity of liver disease in diabetic patients was otherwise milder than in the nondiabetic patients.'] Is diabetes mellitus associated with hepatic encephalopathy in patients with HCV cirrhosis?