Objectives: Nonalcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of metabolic syndrome. Insulin resistance (IR) is a key component of metabolic syndrome. The aim was to determine the dietary composition, physical activity, and histologic severity between NAFLD patients with and without metabolic syndrome.
Methods: Ninety-one patients with NAFLD completed the Block Food Frequency Questionnaire and the Paffenbarger Physical Activity Questionnaire. IR was assessed by the homeostasis model assessment (HOMA) index. Metabolic syndrome was defined by the ATP III clinical definition. Nonalcoholic steatohepatitis (NASH) Clinical Network Scoring System was used to determine the histologic severity of NAFLD.
Results: Thirty-one patients (34%) had metabolic syndrome. Patients with metabolic syndrome had a higher HOMA index (7.66 vs 4.45, p = 0.04), and consumed more carbohydrates (51%vs 45%, p = 0.03) and less fat (34%vs 40%, p = 0.01) compared with those without metabolic syndrome; total daily calorie, protein consumption, and physical activity were similar between the two groups. Patients with metabolic syndrome had higher scores for steatosis (2.0 +/- 0.8 vs 1.37 +/- 1, p = 0.02), NASH activity (4.13 +/- 1.4 vs 3.13 +/- 1.7, p = 0.004), and global NASH score (5.9 +/- 1.7 vs 4.4 +/- 2.3, p = 0.0006) compared with those without metabolic syndrome. When controlled for other factors including dietary composition and physical activity, the presence of metabolic syndrome was a significant risk factor for global NASH severity in addition to HOMA index and female gender.
Conclusion: Metabolic syndrome in patients with NAFLD is associated with a diet containing more carbohydrate and less fat and greater histologic severity. The role of a carbohydrate-restricted diet in decreasing the risk for metabolic syndrome and histologic severity should be assessed in patients with NAFLD.