Prevalence of Hepatic Steatosis and Fibrosis in the United States

Introduction: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. We evaluated vibration-controlled transient elastography (VCTE) data to determine the prevalence of two principle manifestations of NAFLD, hepatic steatosis and hepatic fibrosis. Methods: Data were sourced from the 2017 to 2018 National Health and Nutrition Examination Survey, which provides a representative cross-section of the noninstitutionalized U.S. population. Participants 18 years of age and older were examined using sera and VCTE. Sociodemographic and medical history information were gathered through self-report. Logistic regression models assessed relationships between steatosis, fibrosis, and variables of interest. Prevalence estimates are reported as weighted percentages with 95% Wald confidence intervals (CIs). Results: A total of 4083 participants representing 187 million U.S. adults were included in our analysis. We estimate the prevalence of steatosis (controlled attenuation parameter ≥302 dB/m, ≥S1) at 27.3% (95% CI: 25.3-29.4) and significant fibrosis (liver stiffness ≥8.2 kPa, ≥F2) at 7.7% (95% CI: 6.1-9.6). Both were independently associated with age, gender, body mass index (BMI), and diabetes (all P < 0.05). The greatest predictor of both steatosis and fibrosis was BMI. Steatosis was present in 3.6%, 18.7%, and 49.4% of those in the normal or underweight, overweight, or obese categories, respectively. Significant fibrosis was present in 2.1%, 3.2%, and 14.7% of those in the normal or underweight, overweight, or obese categories, respectively. Conclusions: Clinically significant steatosis and/or fibrosis are highly prevalent among the U.S. adult population. The greatest predictor of both steatosis and fibrosis is obesity.