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.