Significance of the 13C-caffeine breath test for patients with cirrhosis.

BACKGROUND: The 13C-caffeine breath test (CBT) is a non-invasive, quantitative test of liver function which has been shown to correlate inversely to the Child-Pugh score. The aim of the study was to determine the utility of CBT in the assessment of cirrhosis and its correlation to the model for end-stage liver disease (MELD) score. METHODS: Thirty-nine patients, 29 with cirrhosis and 10 with chronic liver disease without cirrhosis, and 8 healthy volunteers were included. Cirrhotic patients were graded according to Child-Pugh and MELD scores. All participants underwent CBT and laboratory tests on the same day. The results of the CBT were expressed as percentages of changes over baseline values (Δ‰) per 100 mg caffeine. RESULTS: The mean single 15-min, 30-min, 45-min and 1-h CBT results, as well as cumulative CBT values differed significantly between healthy controls or chronic liver disease patients and cirrhotics (1-h CBT: 3.22±1.06 or 3.56±2.80 vs. 1.69±2.52, P≤0.01). In contrast, the CBT results at any time point or cumulative values did not correlate with MELD or Child-Pugh scores. Receiver operating characteristics (ROC) analysis showed that the 30-min CBT values were more accurate in differentiating cirrhotics from chronic liver disease patients (area under ROC curve: 0.871). CONCLUSIONS: CBT can reliably differentiate the patients with decompensated cirrhosis from non-cirrhotic patients with chronic liver diseases. However, in patients with decompensated cirrhosis, CBT results do not seem to be associated with the Child-Pugh and MELD scores.

Liver function breath tests for differentiation of steatohepatitis from simple fatty liver in patients with nonalcoholic Fatty liver disease.

GOALS: We investigated the utility of liver function breath tests [C-Aminopyrine Breath Test (C-ABT), C-Galactose Breath Test (C-GBT)], for the diagnosis of nonalcoholic steatohepatitis (NASH) among nonalcoholic fatty liver disease (NAFLD) patients. BACKGROUND: Liver biopsy is currently the gold standard for the differentiation between simple fatty liver (NAFL) and NASH in NAFLD patients. MATERIALS AND METHODS: Thirty-six patients with histologically proven NAFLD (NAFL:16, NASH:20) underwent C-ABT and C-GBT. The results were expressed as the percentage of administered C dose recovered per hour (%dose/h) and as cumulative percentage of administered C dose recovered over time (%cumulative dose). Histologic lesions were scored according to Brunt and Kleiner's classifications. RESULTS: C-ABT results correlated inversely with activity grade (r=-0.650, P=0.001), NAFLD activity score (r=-0.473, P=0.026), and fibrosis stage (r=-0.719, P=0.001). Compared with NAFL, NASH patients had significantly lower %dose/h and %cumulative dose at 60, 90, and 120 minutes (always P<0.04) by C-ABT. C-ABT %dose/h and %cumulative dose at 120 minutes could predict the presence of NASH (area under the receiver operating characteristic curve: 0.762 and 0.741, respectively). In contrast, there was no significant association between C-GBT results and any patient characteristic. CONCLUSIONS: In the NAFLD patients, decreased and delayed liver microsomal function, as assessed by C-ABT, is associated with more severe necroinflammation and fibrosis, whereas C-ABT results at 120 minutes may be helpful for the diagnosis of NASH.

Non-alcoholic fatty liver disease may develop in individuals with normal body mass index.

BACKGROUND: Although non-alcoholic fatty liver disease (NAFLD) is associated with obesity and metabolic syndrome (MS), it may also be present in lean individuals. We evaluated the characteristics of NAFLD patients, focusing on those with normal body mass index (BMI). METHODS: One hundred and sixty-two of 185 consecutive NAFLD patients were included (23 were excluded due to missing data). NAFLD diagnosis required elevated ALT and/or GGT, hepatic steatosis on ultrasonography and no other cause of liver disease. Demographic, clinical, somatometric and laboratory characteristics were recorded. BMI <25 kg/m2 was considered normal. RESULTS: Normal BMI was present in 12% of patients. Patients with normal compared to those with increased BMI had numerically but not significantly lower prevalence of diabetes mellitus (6% vs. 15%, p=0.472), arterial hypertension (17% vs. 29%, p=0.276) and MS (20% vs. 41%, p=0.160). Normal BMI NAFLD patients met no criterion of MS more frequently (43% vs. 2%, p<0.0001) and had smaller waist circumference (94±6 vs. 108±10 cm, p<0.001), higher median levels of ALT (92 vs. 62 IU/L, p=0.032) and AST (45 vs. 37 IU/L, p=0.036) and relatively lower fasting glucose levels (98±22 vs. 106±29 mg/dL, p=0.052), but similar levels of HDL, LDL and triglycerides. CONCLUSION: Approximately 1 of 8 NAFLD patients coming to the tertiary liver center has normal BMI. These patients do not necessarily have insulin resistance associated metabolic disorders, but they have higher levels of ALT/AST than the overweight or obese NAFLD patients.