Screening for chronic liver diseases in the general population reveals an unexpectedly high prevalence of hepatitis c and advanced NAFLD

Background and Aims: Hepatitis C virus (HCV) infection and non-alcoholic fatty liver disease (NAFLD) are common causes for chronic liver disease and are associated with an increased risk for advanced liver disease as well as cardiovascular disease (CVD). Data on the prevalence of liver diseases such as chronic viral hepatitis or fatty liver disease in particular are limited. The cost-effectiveness of population-based HCV screening to achieve WHO goals for eradication of HCV infection is under debate. Here, we provide preliminary data of a population-based combined Hepatitis C and NAFLD screening program in Austria.
Method: As part of a colorectal carcinoma colonoscopy screening program (SAKKOPI), we investigated 661 asymptomatic subjects (median age 58.8 years [53.3–64.4], 56% males). The diagnosis of fatty liver disease was established by abdominal ultrasound and transient elastography-based controlled attenuation parameter (CAP) ≥ 280 dB/m after exclusion of autoimmune or hereditary liver diseases, excess alcohol consumption and previously diagnosed viral hepatitis. Assessment of fibrosis using transient elastography (≥7 kPa for significant fibrosis [≥F2] and ≥ 10 kPa for cirrhosis [F4]) as well as biochemical and metabolic parameters, including liver enzymes, oral glucose tolerance test, insulin resistance (HOMA-IR) and HbA1c was performed. In addition, a detailed questionnaire of dietary habits and physical activity was completed. If serologic testing was positive for HCV antibodies, HCV infection was confirmed by PCR.
Results: In 661 patients, median BMI was 25.9 (23.4–29.0). 200 patients (30%) had elevated liver enzymes (GGT/ALT) and 246 (37%) had ( pre-) diabetes. Mean Fib4 score was 1.07; 527 patients (80%) had Fib4 scores <1.45, while 123 (19%) and 11 (2%) had scores between 1.45–3.25 and >3.25 (indicative for advanced fibrosis), respectively. 42% of patients showed increased echogenicity on ultrasound examination. On transient elastography, mean CAP-value was 265 dB/m (221–311), whereas 269 (42%) patients had CAP-values above 280 dB/m. 63 (10%) of NAFLD patients had significant fibrosis (≥F2) and 16 (2.5%) had liver cirrhosis. Furthermore, 6 patients (0.9%) had detectable HCV antibodies. 5 of them (0.8%) had chronic HCV infection confirmed. Notably, two patients with chronic HCV infection had completely normal laboratory, ultrasound and transient elastography findings.
Conclusion: We show an unexpectedly high prevalence of chronic HCV infection and advanced NAFLD in a large, well-characterized cohort of asymptomatic patients. Especially the high prevalence of undetected HCV infections (0.8%) emphasizes the need for HCV screening in a population-based manner. Importantly, 40% of individuals with unknown HCV infection did not show any evidence for chronic liver disease, which would leave them without diagnosis and treatment.