Importance of cardiometabolic risk factors in the association between nonalcoholic fatty liver disease and arterial stiffness in adolescents

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwideand is regarded as the hepatic manifestation of the metabolic syndrome. In adults,NAFLD is a determinant of arterial stiffness and cardiovascular risk, independent of themetabolic syndrome. Our aim was to ascertain if NAFLD is associated with arterial stiffness,independent of cardiometabolic factors in a population-based cohort of adolescents.The 17-year-olds (n 5 964) from an Australian birth cohort had measures of anthropometry,blood pressure, fasting insulin, glucose, lipids, and NAFLD by ultrasound. Two-stepcluster analysis identified youth at high metabolic risk. Measures of arterial stiffness (pulsewave velocity [PWV] and augmentation index corrected for heart rate [AI@75]) wereobtained using applanation tonometry. The overall prevalence of NAFLD was 13.3%. The“high risk” metabolic cluster at age 17 years included 16% males and 19% females. Comparedto “low risk,” the “high risk” cluster participants had greater waist circumference,triglycerides, insulin, systolic blood pressure, and lower high-density lipoprotein (HDL)cholesterol (all P < 0.0001). Those who had NAFLD but were not in the “high risk”metabolic cluster did not have increased PWV or AI@75. However, males and femaleswho had NAFLD in the presence of the metabolic cluster had greater PWV (b 5 0.20,95% confidence interval [CI] 0.01 to 0.38, P 5 0.037). Males who had NAFLD in thepresence of the metabolic cluster had greater AI@75 (b 5 6.3, 95% CI 1.9 to 10.7, P 50.005). Conclusion: NAFLD is only associated with increased arterial stiffness in the presenceof the “high risk” metabolic cluster. This suggests that arterial stiffness related to thepresence of NAFLD is predicated on the presence of an adverse metabolic profile inadolescents. (HEPATOLOGY 2013;58:1306-1314)