[The efficacy of transient liver elastography overweight patients with chronic liver diseases]

Transient elastography (TE) allows evaluating the liver fibrosis stage indirectly and noninvasively. High correlation between results with liver fibrosis stage was shown previously. It was suggested that availability and reproducibility of the method is low in patients with excessive.

To evaluate availability, reproducibility and diagnostic accuracy of transient elastography in patients with different body mass index (BMI) and liver fibrosis stage.

Two hundred patients with chronic liver diseases (predominantly with chronic hepatitis C, n = 135) were enrolled. Among them 100 were included to the group with BMI > or = 25 kg/m2 (M +/- m 29,58 +/- 3,7 kg/m2) and 100 patients with BMI < 25 kg/m2 (M +/- m 22,07 +/- 2,1 kg/m2). Liver stiffness measurements were performed using FibroScan (EchoSens, France), M-type probe. Metavir grading score was used to estimate liver fibrosis stage. Availability of TE was assessed by counting the proportion of patients with successful examination (22 measurements, success rate > 30%) per group. The reproducibility of TE was studied by counting intra-observer agreement (correlation between results of two series by 11 measurements obtained during examination of the patient) and inter-observer agreement between the results of examinations of the patient by two independent skilled operators obtained on the same day. Diagnostic accuracy was estimated using concordance of the results of liver histology and TE with following cut-off values: 5.8 kPa for F0, 7.2 kPa for F2, 9.5 kPa for F3 and 12.5 kPa for F4.

Availability of TE was lower for patients with BMI > or = 25 kg/m2: 87,13% vs 99% (BMI < 25 kg/m2), p < 0,05. Intra-observer agreement was excellent and did not differ between both studied groups: 0.986595% CI [0.9794-0.9911] for the group with BMI > or = 25 kg/m2, and 0.990095% [0.9851 -0.9931] for patients with BMI < 25 kg/m2, p = 0.3122. Inter-observer agreement was higher for group with BMI > or = 25 kg/m2 (0.987, 95% CI [0.981 -0.990]) then in group with BMI < 25 kg/m2, p = 0.037. The diagnostic accuracy did not differ between groups with excessive weight compared to the BMI < 25 kg/m2 group related to liver fibrosis stage: 65.4% vs. 72.2%, p = 0.59 for F0, 68.1% vs. 70.5%, p = 0.84 for F1, 75.2% vs. 82.1%, p = 0.65 for F2, 84.1% vs. 88.8%, p = 0.76 for F3, 92.2 vs. 94.4, p = 0.85 for F4, accordingly.

The availability of TE is lower for patients with an excessive weight. TE is highly reproducible method. The diagnostic accuracy of TE with taken cut-off values was fair and did not differ between both weight groups.