The growing prevalence of nonalcoholic fatty liver disease (NAFLD), determined by fatty liver index, amongst young adults in the United States. A 20-year experience

Abstract

Aim: The Global burden of nonalcoholic fatty liver disease (NAFLD) has significantly increased recently, with its prevalence mirroring increasing obesity and diabetes. However, population-specific evidence for young adults remains limited. Herein, we provide a 20-year trend analysis of NAFLD in young adults and examine factors associated with NAFLD and major adverse cardiovascular events (MACE) prevalence. Methods: This study uses data from the United States National Health and Nutrition Examination Survey (NHANES) 1999-2018. Fatty liver was examined with the fatty liver index (FLI) and United States-FLI (US-FLI), and advanced fibrosis was examined with the fibrosis-4 index. Clustered multivariate logistic regression analysis on the year of study was applied to obtain odds ratios (OR) for the estimation of events. Results: 13.31% (95%CI: 12.71% to 13.94%) of young adults had NAFLD. The prevalence increased from 9.98% in 1999 to 19.49% in 2018, with a statistically significant trend (P < 0.001). 9.52% and 5.29% of patients have clinically significant and advanced fibrosis, respectively. In multivariate analysis, diabetes (3.48, 95%CI: 2.37 to 5.11), hypertension (2.03, 95%CI: 1.62 to 2.55), elevated body mass index (1.22, 95%CI: 1.20 to 1.23, P < 0.001) significantly increases odds of NAFLD. The largest increase in odds was related to obesity (OR: 21.61, 95%CI: 16.95 to 27.55, P < 0.001). Young adults with NAFLD had a borderline non-significant increase in the prevalence of MACE compared to individuals without NAFLD (OR: 1.603, 95%CI: 0.949 to 2.708, P = 0.078). Conclusion: The rising prevalence of NAFLD in young adults depicts the changing landscape of NAFLD and its association with a significant increase in MACE. The challenge of effective risk stratification and education of these individuals remains.

The prognostic value of including non‐alcoholic fatty liver disease in the definition of metabolic syndrome

“…30,31 In young adults, an estimated 13.31% have NAFLD but only 5% and 18% of NAFLD young adult patients have DM and HTN, respectively, which may suggest NAFLD as an early marker of metabolic dysfunction. 32 Fatty liver is a pre-requisite for highly atherogenic dyslipoproteinaemia, which stimulates insulin dysregulation that progresses into metabolic syndrome.…”

“…This is unsurprising given that NAFLD is not an innocent bystander in causing metabolic derangements from the presence of significant oxidative stress, lipid peroxidation caused by increased triglyceride and VLDL levels due to insulin resistance driven free fatty acid overproduction 30,31 . In young adults, an estimated 13.31% have NAFLD but only 5% and 18% of NAFLD young adult patients have DM and HTN, respectively, which may suggest NAFLD as an early marker of metabolic dysfunction 32 . Fatty liver is a pre‐requisite for highly atherogenic dyslipoproteinaemia, which stimulates insulin dysregulation that progresses into metabolic syndrome.…”

Racial and ethnic disparities in metabolic dysfunction-associated steatotic liver disease

“…As the global incidence of obesity and diabetes mellitus increases, so does the global incidence of MASLD [4] . Obesity is a major risk factor for MASLD, and both body mass index and waist circumference have been shown to be positively correlated with the presence of MASLD and its progression [5,63] .…”

“…The global prevalence of MASLD is estimated to be 30 percent, with the highest prevalence in the Middle East and North Africa (26.5 percent each) [3] . The incidence of MASLD is increasing due to the rising incidence of obesity and diabetes mellitus [4] . The NHANES 1999-2018 survey found that the prevalence of MASLD in young adults in the United States increased from 9.98% in 1999 to 19.49% in 2018 [5] .…”