THE ROLE OF MACRONUTRIENTS IN THE PROGRESSION OF NONALCOHOLIC FATTY LIVER DISEASE (NAFLD). PRELIMINARY DATA ON 30 OBESE PATIENTS

Background and aim: In obesity with no history of alcohol abuse, liver steatosis (NAFLD) is associated with a cluster of metabolic alterations, particularly insulin resistance (IR). IR induces advanced liver fibrosis leading progressively NAFLD to cirrhosis, through steatohepatitis (NASH). A noninvasive simple scoring system was recently suggested to identify the risk of fibrosis in NAFLD patients (Angulo et al, 2007). On the other hand nutrient intake affects IR and it plays an important role in NAFLD progression to NASH. We have investigated the possible correlations between the suggested markers of metabolic and liver damage: IR by Homeostasis Model Assessment (HOMA-IR), alanine aminotransferase (ALT), gamma glutamyltranspeptidase (GGT), the NAFLD Fibrosis Score (FS) and the macronutrient (proteins, lipids, carbohydrates) intakes. Material and methods: From May to Sept. 2008, 30 obese patients (F24; age 21-61 y) with BMI 31-54, were consecutively selected after admission to our digestive endoscopy service for the intragastric balloon insertion. Clinical and laboratory data were collected; HOMA-IR (values >2.5 = IR) and FS (> -1.455 =possible fibrosis) were calculated. Patients with HBV(+), HCV(+), alcohol abuse, and steatogenic drugs in the history, were excluded. Dietary habits were obtained by detailed questioning and a computed database determined total energy and macronutrient intakes, according to the standard table of food composition in Italy (ed. 2000). Results:Waistline was higher than normal (F/M<88/102 cm) in F 71% and in M 100%. The investigated values were increased for HOMA-IR, ALT, GGT, FS in 71%, 40%, 15%, 50% of the patients, respectively. Total energy (kcal) intake correlated with HOMA-IR values (r =0.36, p<0.001), ALT (r =0.48, p<0.01), GGT (r =0.38, p<0.05) and FS (r=0.38, p<0.05); protein intakes correlated with ALT (r =0.46, p<0.05), GGT (r =0.38, p<0.05); lipid intakes correlated with HOMA-IR (r=0.58, p<0.01) and ALT (r =0.55, p<0.05); carbohydrate (r =0.50, p<0.01) and simple carbohydrate (r =0.42, p<0.05) intakes correlated with FS. Conclusions: A significant correlation was observed between ALT values and total energy, protein, lipid intakes, confirming the role of sensitive marker in liver damage. As recently suggested (Lê KA, 2008) the intake of carbohydrates, especially simple carbohydrates, enhances the risk of progressive liver fibrosis.