Seventy five g oral glucose tolerance test (OGTT) has been recently proposed. Little is known, however, on the results by the new test in various liver diseases.
Studies were conducted with 59 patients with liver diseases : 11 acute viral hepatitis (AVH), 5 chronic inactive hepatitis (CIH), 14 chronic active hepatitis (CAH), 13 liver cirrhosis (LC), 10 fatty liver (FL) and 6 hepatic fibrosis (HF). Eighteen healthy volunteers served as control. Blood samples were taken at 0, 30, 60, 90, 120 and 180 min after oral loading of 75 g glucose, and stored frozen until radioimmunoassay for immunoreactive insulin (IRI) and glucagon (IRG). Blood sugar levels were determined by glucose oxidase method.
The results obtained herein were as follows :
(1) None of the patients studied showed fasting blood sugar level more than 140 mg / dl. In contrast, 29 % of CAH, 23 % of LC and 17 % of HF had blood sugar level more than 200 mg / dl at 120 min, indicating the diabetic type (A committee report on the diagnosis of diabetes mellitus, Japan, 1982).
(2) Exaggerated IRI responses to glucose stimulation were observed in most of the patients with liver diseases, particularly in LC and CAH.
(3) A significant elevation in the basal IRG level was observed in LC. Circulating IRG levels tended to be suppressed by glucose.
(4) The mean values of insulinogenic index (Δ IRI / Δ BS, 30 min) appeared to be higher in liver diseases than in diabetes mellitus, as described previously (AVH 2.26, CIH 0.64, CAH 0.81, LC 1.15, FL 1.32, HF 0.65).
From these observations, it is concluded that approximately 20 % of CAH, LC and HF belongs to the diabetic type, according to 75 g OGTT. The degree of glucose intolerance in patients with liver diseases is relatively mild. However, we should emphasize that serum IRI response to glucose may be useful in the differential diagnosis between glucose intolerance in liver diseases and diabetes mellitus.