Background: Nonalcoholic fatty liver disease (NAFLD) has been linked to cardiovascular disease (CVD) but it is largely unknown if such a relationship between NAFLD and CVD risk relates to severity of liver disease or if it is independent. We aimed to study the severity of NAFLD in a well characterized non-obese population and to compare this to prevalence of CVD risk factors and Framingham risk score.
Methods: This study included 30,172 subjects. Based on the presence or absence of steatosis on ultrasound and serum alanine aminotransferase (ALT), subjects were divided into controls, an increased serum ALT group without steatosis and a group with presumed nonalcoholic fatty liver disease (NAFLD), which included a steatosis alone group and a group with presumed nonalcoholic steatohepatitis (NASH) with steatosis and an elevated ALT.
Results: The odds ratio for 10-year risk by total Framingham risk scores > or =10% was 5.3 times higher in NASH groups. The prevalence of diabetes, hypertension, elevated CRP and metabolic syndrome were all increased up to 15-fold over controls, independent of age, BMI, smoking and exercise habits. Overall CVD risk was significantly greater in NASH than in either steatosis or raised ALT alone.
Conclusion: Young, non-obese subjects with NAFLD are at significantly increased CVD risk, especially those with NASH. As well as specific therapy for liver disease, a diagnosis of NAFLD should lead to targeted risk assessment and risk factor modification.