Insulin resistance and metabolic syndrome in patients with NAFLD but without diabetes : effect of a 6 month regime intervention

Background and study aims : Non-alcoholic fatty liver disease (NAFLD) and the metabolic syndrome are two intertwined diseases sharing the same factor in their pathogenesis ; insulin resistance. The aim of the study was to establish a link between glucose tolerance and NAFLD. Patients and methods : Fifty-two non-diabetic NAFLD patients were included in the study. Inclusion criteria were elevated alanine aminotransferase (ALT), hyperechogenic liver detected at ultra- sonography, and exclusion of other causes of liver disease. Hepatobiliary ultrasonography and laboratory tests including biochemical and metabolic profiles were performed; HOMA insulin resistance was calculated. Results : The mean age was 43 years, and 61% were male. More than a two fold increase in alanine aminotransferase levels was seen in 37% of the patients. Serum levels of aspartate aminotrans- ferase, gamma-glutamyl transferase, alkaline phosphatase (ALP) were elevated in 36%, 46%, and 30% of patients respectively. Low HDL-C levels were found in 46% and high LDL-C levels in 25%. Other results of note were elevated lipoprotein-a levels in 40%, impaired fasting glucose in 23%, impaired glucose tolerance in 26%, elevated fasting c-peptide levels in 61%, and elevated fasting serum insulin levels in 11% of patients. In 30% of patients, body mass index was over 30 kg/m2 and 78% had a waist-hip ratio more than 0.9. HOMA insulin resistance was significantly related with elevated ALP levels and hepatomegaly. Following a 6 months treatment with a standard diet, liver enzymes and metabolic parameters both improved. Only 7 patients had persistently high liver enzymes. Conclusions : Basal insulin levels and the oral glucose tolerance test should be an integral part of the evaluation of patients with NAFLD. The association between NAFLD and metabolic syn- drome as well as the benefits of dieting on preventing progression of NAFLD should be stressed. (Acta gastroenterol. belg., 2007, 70, 253-259).