Fasting plasma caffeine level in cirrhotic patients: relation to plasma levels of catecholamines and renin activity.

Fasting plasma caffeine concentrations, plasma levels of catecholamines and plasma renin activity were measured in patients with cirrhosis and control patients without hepatic dysfunction. A careful dietary history showed no significant difference in caffeine consumption (mean +/- S.E.) among 46 cirrhotics (86 +/- 7 mg per day) vs. 34 control patients (91 +/- 8 mg per day). Fasting plasma caffeine concentrations, however, were significantly higher (7.68 +/- 1.42 micrograms per ml) in cirrhotics than in controls (1.01 +/- 0.20 micrograms per ml) (p less than 0.01). Fasting plasma caffeine concentrations in cirrhotics varied significantly with Child's criteria, namely Child's A patients (2.06 +/- 0.38 micrograms per ml); Child's B patients (6.92 +/- 1.86 micrograms per ml), and Child's C patients (17.70 +/- 3.65 micrograms per ml) (p less than 0.001). In 44 cirrhotics, fasting plasma caffeine concentrations were compared with plasma levels of catecholamines and plasma renin activity. Plasma epinephrine concentrations were normal; however, plasma norepinephrine concentrations were increased in six cirrhotics, and plasma renin activities were increased in 28 cirrhotics. After a 3-day caffeine abstinence, plasma caffeine concentration and renin activity were significantly decreased (p less than 0.01), and high plasma norepinephrine levels were also decreased in 12 cirrhotics. Plasma caffeine concentration, renin activity and norepinephrine level did not change in a control group of cirrhotics who continued to receive caffeine for 3 days (n = 6). After abstinence from caffeine, the decrease of fasting plasma caffeine concentration correlated well with the decrease of plasma renin activity (r = +0.746, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)