Nonalcoholic Fatty Liver Disease Alone Is a Better Predictor of Metabolic Syndrome and Insulin Resistance than Existing ATP-III Criteria

Metabolic syndrome is defined as a constellation of certain metabolic abnormalities that render an individual at higher risk for subsequent development of cardiovascular disease (CVD) and diabetes mellitus (DM). The concept and criteria for this syndrome were evolved by the World Health Organization in 1998. This was later modified by National Cholesterol Education Program (NCEP): Adult Treatment Panel III (ATP-III) and International Federation of Diabetes (IDF). The major features of the metabolic syndrome are central obesity, hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hyperglycemia and hypertension.

All the components of this syndrome share insulin resistance (IR) which is the common denominator and is responsible for the vascular and metabolic sequelae. Despite the increase in the prevalence of the components of the metabolic syndrome in obesity, all obese subjects do not develop the syndrome, and on the contrary, even some lean individuals can be insulin resistant. It has been observed that the liver, once fatty, is insulin resistant and overproduces both glucose and VLDL leading to hyperglycemia, hypertriglyceridemia, and low HDL cholesterol concentration. Nonalcoholic fatty liver disease (NAFLD) which is considered as the hepatic manifestation of metabolic syndrome is defined as fat accumulation in the liver exceeding 5% to 10% by weight, as determined from the percentage of fat-laden hepatocytes by light microscopy, absence of significant alcohol abuse (not exceeding 20 g/day) and other viral, toxic and autoimmune etiologies. NAFLD confers upon the patient increased risk for ischemic heart disease and diabetes mellitus. Inclusion of NAFLD as a criterion for metabolic syndrome has been proposed  but has not yet been incorporated into any criteria. Therefore, this study was planned to assess the possibility of NAFLD as a criterion to diagnose metabolic syndrome. Also, the aim of the study was to assess the validity of NAFLD alone and in combination with existing criteria to diagnose individuals with metabolic syndrome.

Inclusion Criteria                                                                                                           

Consecutive outpatients who presented with functional abdominal pain (ROME III criteria), functional dyspepsia (ROME III criteria) and/or irritable bowel syndrome (ROME III criteria) were included in this study. All these patients were in good general health, and with normal findings on medical history, physical examination, blood counts, and ultrasonography (except for fatty liver).