Nonalcoholic fatty liver disease, liver fibrosis, and cardiometabolic risk factors in adolescence: a cross-sectional study of 1874 general population adolescents.
BACKGROUND
The impact of adolescent nonalcoholic fatty liver disease (NAFLD) on health, independent of fat mass, is unclear.


OBJECTIVE
The objective of the study was to determine the independent (of total body fat) association of ultrasound scan (USS)-determined NAFLD with liver fibrosis, insulin resistance, and dyslipidemia among healthy adolescents.


METHODS
This was a cross-sectional analysis in participants from a UK birth cohort.


METHODS
One thousand eight hundred seventy-four (1059 female) individuals of a mean age of 17.9 years participated in the study.


RESULTS
USS assessed liver stiffness (shear velocity, an indicator of fibrosis) and volume, fasting glucose, insulin, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, alanine amino transferase, aspartate amino transferase, γ-glutamyltransferase, and haptoglobin.


RESULTS
The prevalence of NAFLD was 2.5% [95% confidence interval (CI) 1.8-3.3] and was the same in females and males. Dual-energy X-ray absorptiometry determined total body fat mass was strongly associated with USS NAFLD: odds ratio 3.15 (95% CI 2.44-4.07) per 1 SD (∼10 kg) fat mass. Those with NAFLD had larger liver volumes and greater shear velocity. They also had higher fasting glucose, insulin, triglycerides, low-density lipoprotein cholesterol, alanine amino transferase, aspartate amino transferase, γ-glutamyltransferase, and haptoglobin and lower high-density lipoprotein cholesterol. Most associations were independent of total body fat. For example, after adjustment for fat mass and other confounders, hepatic shear velocity [mean difference 22.8% (95% CI 15.6-30.5)], triglyceride levels [23.6% (95% CI 6.0-44.2)], and insulin [39.4% (95% CI 10.7-75.5)] were greater in those with NAFLD compared with those without NAFLD.


CONCLUSIONS
In healthy European adolescents, 2.5% have USS-defined NAFLD. Even after accounting for total body fat, those with NAFLD have more adverse levels of liver fibrosis and cardiometabolic risk factors.
Medical Research Council Integrative Epidemiology Unit (D.A.L., C.M.-W., E.A., A.F., L.D.H.) and School of Social and Community Medicine (D.A.L., C.M.-W., E.A., A.F., L.D.H.), University of Bristol, Bristol BS8 2BN, United Kingdom; University Hospitals Bristol National Health Service Foundation Trust (M.C.), Bristol BS1 3NU, United Kingdom; Institute of Cellular Medicine (C.D.), Faculty of Medical Sciences, Newcastle University, Newcastle-upon-Tyne NE1 7RU, United Kingdom; and Institute of Cardiovascular and Medical Sciences (N.S.), BHF Glasgow Cardiovascular Research Centre, Faculty of Medicine, University of Glasgow, Glasgow G12 8TA, United Kingdom.
Debbie A
DA
Lawlor
Mark
M
Callaway
Corrie
C
Macdonald-Wallis
Emma
E
Anderson
Abigail
A
Fraser
Laura D
LD
Howe
Chris
C
Day
Naveed
N
Sattar
D000293:Adolescent; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000209:etiology*; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000209:etiology*; D065626:Non-alcoholic Fatty Liver Disease; D012307:Risk Factors; D014463:Ultrasonography; D006113:United Kingdom / Q000453:epidemiology