Non-alcoholic fatty liver disease with and without metabolic syndrome: Different long-term outcomes

Abstract

Background: Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) are both shown to increase the risk of cardiovascular diseases and type 2 diabetes. However, there is a great overlap between these two diseases. The present study was aimed to examine the cardiovascular and metabolic prognosis of non-alcoholic fatty liver disease with and without metabolic syndrome.

Methods: Middle-aged subjects (n=958) were divided into four subgroups, those with NAFLD and MetS, those with NAFLD or MetS, and healthy controls. The baseline characteristics of the subgroups were analyzed. The follow-up time for cardiovascular events was about 16years. After approximately 21years the cardiac ultrasound and laboratory parameters were re-analyzed and new type 2 diabetes cases were recorded.

Results: Those with both diseases were at the greatest risk for cardiovascular events (p<0.001). Compared to healthy controls, only those with MetS, with or without NAFLD, were at increased risk for the development of type 2 diabetes (p<0.001) and for an increase in left ventricular mass index (p=0.001 and p=0.005, respectively). The cardiovascular and metabolic risk in subjects with NAFLD only was quite similar to that in healthy controls. The I148M variant of the patatin-like phospholipase domain-containing 3 gene (PNPLA3 polymorphism) was most present in those with NAFLD only (p=0.008).

Conclusions: NAFLD with MetS implies a considerable risk for cardiovascular diseases, type 2 diabetes and the increase of left ventricular mass index whereas NAFLD without MetS does not.

Keywords: Cardiovascular diseases; Metabolic syndrome; Non-alcoholic fatty liver disease; Type 2 diabetes.