The impact of modifiable risk factors on the long-term outcomes of non-alcoholic fatty liver disease

Background Cardiovascular (CV) disease is the leading cause of mortality in patients with non-alcoholic fatty liver disease (NAFLD). The American Heart Association (AHA) developed 7 CV health metrics (poor, intermediate and ideal health) to improve CV health. Aim To assess population-attributable fractions (PAFs) of CV health metrics to all-cause and CV mortality among NAFLD patients Methods We included adults participants from National Health and Nutrition Examination Survey (NHANES 1988-1994) with clinical and mortality data. NAFLD was defined as the presence of hepatic steatosis on ultrasonography in the absence of other chronic liver diseases and excessive alcohol use. Results A total of 4040 adults with NAFLD and 7515 without were included. NAFLD had fewer ideal health metrics than non-NAFLD (age-standardised prevalence: 20% vs 10% for <= 1 ideal health metric; 5.1% vs 8.7% for >= 6, all P < .001). Following median follow-up of 19.2 years (IQR: 17.5-21.0 years), 1,136 NAFLD subjects (327 CV deaths) and 1600 non-NAFLD subjects (447 CV deaths) died. Increased number of ideal health metrics (all trend P < .0001) equalled lower risk for all-cause and CV mortality. If all NAFLD subjects achieved 7 ideal health metrics, 66% of all-cause deaths and 83% of CV deaths were preventable. Among NAFLD subjects, lack of glycaemic control (adjusted PAF = 28.3% all-cause; 38.1% CV) and hypertension (adjusted PAF of 23% all-cause; 52.8% CV) were the largest mortality contributors. Ideal physical activity level obtainment provided an adjusted PAF = 13.9% all-cause and 13.8% CV mortality. Conclusions Attainment of ideal CV health metrics provides protection against all-cause and CV deaths in NAFLD.