To Örebro University

Background and aims: The rising prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), driven by the obesitepidemic, has made its co-occurrence with other primary livediseases increasingly common. Primary sclerosing cholangitis (PSCis a rare immune-mediated cholestatic liver disease, and there is a gain research aiming to evaluate the prevalence and impact of livesteatosis in PSC. We aimed to evaluate the prevalence of liver steatosiin patients with PSC using controlled attenuation parameter (CAPmeasurements, acquired during transient elastography.

Method: Patients with PSC were enrolled from an ongoing multi-center phase III study of simvastatin (PiSCATIN). Clinical, laboratoryliver MRI data, CAP and liver stiffness measurement (LSM) value(Fibroscan, Echosens, Paris, France) were collected at baseline. Livesteatosis was defined by a median CAP value of ≥254 dB/m, as validated by Steinman et al. in their study on CAP accuracy for detecting steatosis in autoimmune liver diseases. Baseline characteristics were compared between non-steatotic and steatotic patient groups using frequencies or median and IQR. The association between CAP values and these parameters was assessed with uni- and multivariable linear regression models. A 2-tail significance level of p < 0.05 was chosen.

Results: A total of 220 patients with valid CAP values were included, 153 (69.5%) males. The median CAP was 227 dB/m (IQR 80) with a point prevalence of liver steatosis (CAP ≥254 dB/m) of 29% (95% CI 23–35). Patients’ age, sex, PSC type or duration did not differ significantly between steatotic and non-steatotic groups. In both groups the prevalence of IBD was 80%, IBD duration did not differ significantly. Median body mass index (BMI) was 24.1 kg/m² (IQR 5.3) in the non-steatotic group and 27.8 kg/m² (IQR 5.8) in the steatotic group, with fewer lean individuals (BMI <25) in the steatotic group (17% vs. 55%, p < 0.05). Cholesterol and triglyceride levels were higher ( p < 0.05) in steatotic group, with medians of 5.5 mmol/L (IQR 1.25) and 1.2 mmol/L (IQR 0.7), compared to 5 mmol/L (IQR 1.6) and 0.9 mmol/L (IQR 0.45) in the non-steatotic group. The median LSM value was 6.9 kPa (IQR 5.3), with no significant association between CAP and LSM values ( p > 0.05). Multivariable linear regression showed BMI, triglycerides, and diabetes independently associated with CAP ( p < 0.05), but no significant association was found between CAP and MRI findings of advanced liver disease (e.g., liver deformity, ascites, spleen enlargement, and varices).

Conclusion: Although the potential importance of steatosis in PSC prognosis is yet to be determined, the prevalence of liver steatosis in patients with PSC was within the range expected in the general population. Higher BMI and plasma triglyceride levels, but not a more advanced disease stage, are associated significantly with higher CAPvalues.