The impact of hepatic steatosis on portal hypertension

Background and Aims:

Studies in animal models suggested an effect of hepatic steatosis on portal pressure, since diet-induced hepatic steatosis has been shown to promote liver sinusoidal endothelial dysfunction and increase intrahepatic resistance. Thus, we aimed to evaluate the effect of hepatic steatosis on portal pressure in patients with chronic liver disease.

Methods:

Patients who underwent paired hepatic venous pressure gradient (HVPG) and controlled attenuation parameter (CAP, FibroScan, Echosense, France) measurements between 01/2014 and 12/2016 were included in this retrospective study.

Results:

In total, 243 patients with valid HVPG and transient elastography (TE)-based CAP-measurements were identified. The majority of patients (n = 194, 79.8%) had cirrhosis, as according to published disease-specific cut-offs, and 72.8% had clinically significant portal hypertension (CSPH; HVPG ≥10 mmHg). Any hepatic steatosis (S1/2/3; CAP-value ≥248 dB/m) was present in n = 101 (41.6%). Overall, HVPG was comparable between patients with and without hepatic steatosis (14 (2 – 34) vs. 17 (3 – 41) mmHg; p = 0.612). Apart from BMI (Pearson's ρ: 0.136; p = 0.034), no baseline characteristics showed a correlation with CAP.

To control for the severity of liver disease, the correlation between CAP and HVPG was analyzed within HVPG-strata. Neither in patients with subclinical portal hypertension or normal portal pressure (HVPG< 10 mmHg; p = 0.383) nor in patients with CSPH (HVPG≥10; p = 0.495) any correlation between CAP and HVPG could be found. Interestingly, in patients with F2/3 liver fibrosis there was a significant negative correlation between CAP and HVPG (Pearson's ρ: -0.470; p = 0.004). This can be explained by the fact that TE tends to overestimate liver fibrosis stage in patients with pronounced hepatic steatosis. This negative correlation vanished in patients with cirrhosis (F4; Pearson's ρ: -0.096; p = 0.183).

Conclusion:

Hepatic steatosis does not increase portal pressure. Liver stiffness assessment by TE tends to overestimate liver fibrosis stage in patients with hepatic steatosis.