Factors associated with insulin resistance and non-alcoholic fatty liver disease among youths.

OBJECTIVES: To compare the cardio-metabolic risk factors, fitness and lifestyle among adolescents with and without weight disorders and/or metabolic abnormality, and to identify the factors associated with insulin resistance and non-alcoholic fatty liver disease (NAFLD) in this age group.
METHODS: This cross-sectional study comprised 100 adolescents (12-18 years) consisting of four subgroups of normal weight/obese with and without components of the metabolic syndrome. Fasting blood glucose, insulin, lipid profile, apolipoproteins A, B, CRP, oxidized-LDL, malondialdehyde and alanine aminotransferase (ALT) were examined. Cardiorespiratory fitness (CRF) and the sonographic findings of liver and carotid intima media thickness were determined.
RESULTS: Overall 95 participants completed all tests. Serum lipids, lipoproteins, the markers of inflammation and oxidative stress as well as the C-IMT of normal weight children with a metabolic abnormality were similar to obese children. CRF had the highest inverse correlation with HOMA-IR and ALT. Physical activity and healthy eating index had similar inverse correlation with HOMA-IR and ALT. ApoB/ApoA-I had significant independent association with upper quartiles of HOMA-IR and ALT. Waist circumference and ApoB/ApoA-I ratio had the highest odds ratio in increasing the risk of insulin resistance and NAFLD, whereas CRF followed by healthy eating index decreased this risk significantly. C-IMT was significantly associated with insulin resistance and NAFLD.
CONCLUSIONS: We found significant associations between insulin resistance and NAFLD, and similar risk factors and protective factors for these two inter-related disorders; in this regard the role of CRF and apolipoprotein B to apolipoprotein A-I (ApoB/ApoA-I) ratio in the pediatric age group is underscored.