5 The question that remains is what tests clinicians should arrange. Should oral glucose tolerance test (OGTT) be part of the routine workup? The issue of OGTT is not new. Although fasting glucose is commonly used to screen for or diagnose diabetes, it is well known that the correlation between fasting and postprandial glucose is not perfect. In particular, isolated

post-challenge hyperglycemia after OGTT is more often found in male and elderly subjects.6 Using fasting glucose alone, a significant proportion of patients with diabetes or impaired glucose tolerance would be missed. On the other hand, OGTT involves blood taking at two or more time points after oral glucose challenge. This may be inconvenient

and costly to patients and clinicians. The intake of concentrated glucose drinks may also cause gastrointestinal upset and vomiting. Therefore, Selleck BGB324 before one recommends OGTT as a routine test, a few questions need to be answered. How common do NAFLD patients have abnormal OGTT (i.e. number needed to screen)? Does it matter to have subclinical diabetes or impaired glucose tolerance not identified by fasting blood tests alone? Would the finding alter clinical management? In this issue of the Journal, two studies provided important information in this area. Kimura and colleagues performed 75-g OGTT in 173 Japanese biopsy-proven NAFLD patients without prior diagnosis of type 2 diabetes.7 Overall, 60% of the subjects had abnormal OGTT. Thirty-seven percent had impaired glucose tolerance PD0325901 solubility dmso and 23% had diabetes. Although patients with different degree of liver fibrosis had similar glucose levels, those with advanced fibrosis had significantly higher plasma insulin level throughout a 3-h period. After adjusting DCLK1 for age and aspartate aminotransferase level, plasma insulin level at 2 h remained significantly associated with advanced fibrosis. The similar glucose levels among patients

with different fibrosis stages deviates somewhat from our usual understanding. In patients with NAFLD or viral hepatitis, cirrhosis or advanced fibrosis has consistently been associated with increased risk of diabetes.8,9 In fact, cirrhosis itself is a cause of insulin resistance. However, the lack of cirrhotic patients in Kimura’s cohort might partly explain the observation.7 Besides, the mean plasma glucose level among patients with different fibrosis stages was compared using Mann–Whitney U-test. It might be helpful to report the number of patients with impaired glucose tolerance and diabetes in each fibrosis subgroup. In the second article by Manchanayake and colleagues, OGTT was performed in 76 Australian NAFLD patients without prior diagnosis of diabetes.10 One-third of the subjects had abnormal OGTT, with 22% having impaired glucose tolerance and 9% having diabetes. Impaired fasting glucose only had 25% sensitivity in predicting abnormal OGTT.