High Prevalence of Fatty Liver Among Young Adults Ages 18-30 Based on Transient Elastography

Introduction: Hepatic steatosis, or fatty liver (FL), refers to an increase of intracellular fat in the liver and is defined when ≥5% of the liver is intrahepatic fat. It is one of the most common causes of chronic liver disease and may lead to steatohepatitis, fibrosis, cirrhosis, end-stage liver disease, hepatocellular carcinoma, and death. The prevalence of FL ranges from 10% to 46% in the United States. However, the majority of FL studies focus on adults 40+. Liver biopsy is the gold standard for diagnosis of FL, but it is invasive, expensive, and has associated risks. Non-invasive methods such as transient elastography (TE) is an acceptable method for diagnosing FL and liver fibrosis and is rapid, portable, relatively inexpensive, and risk-free. This study aims to determine the prevalence of FL in young adults 18-30 years old using transient elastography (TE). Methods: 141 non-consecutive subjects aged 18-30 were prospectively recruited from community GI clinics, high school, and college campuses from November 2022 to May 2023. Demographics, diet and exercise habits, and alcohol use were self-reported. Height, weight, and waist circumference were measured. A controlled attenuation parameter (CAP) score of ≥238 was considered FL, and liver stiffness >7.0 kPa indicates a fibrosis stage of F2 or higher. CAP score and fibrosis stage was obtained by FibroScan® 230 (Echosens, Paris, France). Results: 33/141 subjects (23.4%) had CAP scores of ≥238. Of those with FL, 6/33 (18.2%) had fibrosis stages of F2-F3. F4 was not detected. We measured BMI and categorized subjects according to CDC BMI guidelines for adults. Among subjects with a BMI ≥25, the prevalence of FL was >50%, regardless of activity level (P< 0.001). We modeled age, sex, and exercise/week vs CAP levels. Effects for sex and exercise did not reach statistical significance. Conclusion: Our study shows an alarmingly high prevalence of FL of 23.4% in young adults aged 18-30. Among young adults with fatty liver, there was also a high prevalence (18.2%) of fibrosis F2 or higher. Only BMI ≥25 was found to be a significant predictor of FL. FL is overlooked in young adults. If left untreated may lead to progression of liver disease. TE may be an efficient, inexpensive method for screening the young population. Identifying and treating FL should begin at the earliest age possible. Interventions at earlier ages may be an effective strategy for combating this silent epidemic. Further studies are needed to corroborate these findings (Table 1). Table 1. - Baseline characteristics of study subjects including self-reported demographic information and measured parameters Base Characteristics of Study Population N Percent Mean Standard Deviation Age (18-30 years) 141 22.6 3.6 Gender Male 77 54.6 Female 64 45.4 Height (in) 68.1 4.5 Weight (lbs) 170.5 40.2 Waist Circumference (in) 32.2 6.2 Body Mass Index (BMI) 25.8 5.8 Self-Reported Alcohol Use None 56 39.7 Any 85 60.3 Amount of Moderate to Strenuous Exercise per Week < 2.5 Hours 60 42.6 ≥ 2.5 Hours 81 57.4 Household Income < $10,000 21 14.9 $10,000 - $40,000 30 21.3 $40,000 - $85,000 15 10.6 $85,000 - $165,000 29 20.6 $165,000 - $210,000 15 10.6 > $210,000 31 22.0 Education High School Graduate or Less 26 18.4 Some College 102 72.3 Post-Graduate Degree 13 9.2 Race/Ethnicity White 59 41.8 Asian 35 24.8 Hispanic 17 12.1 Native Hawaiian or Pacific Islander 2 1.4 African American 2 1.4 Middle Eastern or North African 8 5.7 Two or More Races 18 12.8 Food Insecurity Yes 13 9.2 No 128 90.8 Fast Food Consumption Never 3 2.1 Rarely 82 58.2 Often (Not Everyday) 53 37.6 Daily 3 2.1