[Comparison of fasting glucose and oral glucose tolerance tests in diagnosis of diabetes mellitus in liver cirrhosis]

ABSTRACT

Diabetes mellitus [DM] and glucose intolerance are commonly associated with liver cirrhosis and considered as important prognostic factors in liver cirrhosis. To determine the more sensisitive test for diagnosis of diabetes mellitus in liver cirrhosis. A total of 92 patients with liver cirrhosis were enrolled in a descriptive-analytic study. The levels of FBS and blood sugar two hours after ingestion of 75gr glucose [OGTT] were measured. FBS and 2-hPG concentrations were analysed for all subjects. Chi-square test and Fisher's exact test were used to analyse the data and p values <0.05 were considered as significant. A total of 92 cirrhotic cases with mean age of 54.1 +/- 14.1 years were enrolled in this study of which 51 cases were males [55.4%] and 41 females [44.6%]. Using FBS measurement test, DM was diagnosed in 14 subjects [15.2%], impaired fasting glucose [IFG] in 16 subjects [17.4%], and normal fasting glucose in 62 subjects [67.4%]. However, when OGTT was employed, DM found to be present in 36 subjects [39.1%] impaired glucose tolerance [IGT] in 26 subjects [28.3%], and normal glucose tolerance [NGT] in 30 subjects [32.6%]. Comparison of FBS and OGTT [as gold standard test] showed that there was a significant difference between two tests [p<0.001]. The sensitivity of FBS test to diagnose DM was 46.7% with a specificity of 96.7%. The P.P.V and NPV were 96.7% and 46.7%, respectively. The FBS cut off was estimated at 83.50 mg/dl. The determination of FBS level seems to be insufficient in detecting DM in patients with liver cirrhosis. Thus, in addition to FBS measurement, the OGTT, as a routine test for cirrhosis, is recommended