VIENNA – The prevalence of liver steatosis among unselected English young adults was 21% in a study of just over 4,000 people. The prevalence of apparent liver fibrosis was 2.4%, and among the 21% with steatosis, nearly half – 10% of the studied cohort – had severe, S3 steatosis.
The prevalence of steatosis, a marker of nonalcoholic fatty liver disease (NAFLD), seemed to be linked with obesity. Among the 79% of the study group who had no steatosis the obesity prevalence was 6%, compared with a 26% prevalence among those with S1 steatosis, a 33% obesity rate among those with S2 steatosis, and a 57% obesity prevalence among those with S3 steatosis, Kushala Abeysekera, MBBS, said at the meeting sponsored by the European Association for the Study of the Liver.
He and his associates determined these prevalence rates in a population that excluded people who reported consuming what was deemed “excessive” alcohol use.
Another notable finding was that 1,874 of the same people had undergone ultrasound assessment for NAFLD when they were 18 years old, and that assessment found a prevalence of 2.5% (J Clin Endocrinol Metab. 2014 March;99[3]:e410-7), which meant that during the subsequent 6 years prevalence of NAFLD jumped nearly 900%.
Both the 2014 report and the current study used people who had been enrolled in the Avon Longitudinal Study of Parents and Children, a prospective population-based study that began by recruiting a cohort of more than 14,000 pregnant women during 1991-1992, and then followed the more than 13,000 children who resulted from those pregnancies. The study reported by Dr. Abeysekera focused on 4,021 of these children – now young adults – who responded to an invitation to participate in this follow-up, a number that then reduced to 3,600 with informative transient elastography results that quantified fibrosis, and 3,768 with valid Controlled Attenuated Parameter scores from elastography that reflected steatosis extent. Transient elastography is a noninvasive method of measuring liver stiffness using ultrasound and an elastic shear wave (Clin Mol Hepatol. 2012 June;18[2]:163-73).
“To the best of my knowledge, this is the only study that has assessed NAFLD in young adults using transient elastography,” said Dr. Abeysekera, an epidemiologist at the University of Bristol (England).
After subtracting from the study cohort people with excessive alcohol use, the study had transient elastography data from 3,277 24-year-olds that could calculate steatosis severity, and data from 3,128 that could quantify fibrosis.
The analysis also showed a statistically significant link between sex and the presence and severity of steatosis. Among women, 18% had steatosis, including 7% with S3 steatosis, defined as involving at least two-thirds of the liver. Among men, 26% had some degree of steatosis and 14% had the most severe form.
The presence of more severe liver fibrosis also showed a strong link to obesity. The eight people identified with F4 fibrosis (with cirrhosis) had a median body mass index of 32 kg/m2, compared with a median body mass index of 25 kg/m2 or less among those either without fibrosis or with a milder form of F1, F2, or F3 fibrosis.
Dr. Abeysekera reported no disclosures.