Background: The C-caffeine breath test (CBT) is a noninvasive tool for the evaluation of the cytochrome P450 system, implicated in the development of nonalcoholic steatohepatitis.
Goal: To apply the CBT to assess the extent of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).
Methods: Twenty-six consecutive patients (mean age 56.1+/-6.85 y, 69.2% women) with NAFLD underwent the CBT, in addition to the clinical and laboratory evaluations and liver biopsy. Ten healthy individuals matched for age served as controls.
Results: Mean delta over baseline values differed significantly between patients and controls (1.51+/-0.9 vs. 2.37+/-0.8 Delta per thousand/mg, respectively) (P=0.01) and were significantly higher in patients with fibrosis stage <2 (Brunt's system) (2.0+/-0.77 vs. 1.3+/-0.9 for stage > or =2, P=0.05). Mean delta over baseline values correlated highly with fibrosis stage (P=0.01), albumin (P=0.007), international normalized ratio (P=0.04), bilirubin (P=0.0008), and platelet count (P=0.0001). On multivariate stepwise logistic regression analysis, CBT was the best predictor of severe fibrosis (stage > or =2) (odds ratio 0.274, 95% confidence interval 0.086-0.872, P=0.028), with an area under the curve of 0.788.
Conclusions: The CBT is safe and easy to perform. It can reliably predict severe hepatic fibrosis in patients with NAFLD. Further large-scale studies are still needed.