Background and aim: In obesity, nonalcoholic fatty liver disease (NAFLD) is mostly associated with insulin resistance (IR). Even a slight increase of liver enzymes highlights the hepatic injury. IR also induces liver fibrosis leading progressively NAFLD to cirrhosis. Angulo et al. (2007) suggested a noninvasive simple scoring system that may predict the risk of fibrosis in NAFLD patients: the NAFLD fibrosis score. The aim was to investigate the values of IR by Homeostasis Model Assessment (HOMA-IR), aspartate transaminase (AST), alanine aminotransferase (ALT), gamma glutamyltranspeptidase (GGT), and the NAFLD Fibrosis Score (FS) in obese and severely obese patients. Material and methods: From Jan. to Nov. 2008, 84 obese patients (age 18-68 y; F 60; BMI 31-54 kg/m2), were consecutively selected after admission to our Gastroenterology Unit for the bariatric therapy assessment. Clinical and laboratory data were collected. IR was calculated by the Homeostasis Model Assessment (HOMA-IR), as fastingserum insulin (µU/ml) × fasting plasma glucose (mmol/l)/22.5; values >2.5 indicate a state of IR. The FS was determined by six variables as previously suggested (>-1.455 = possible liver fibrosis). Patients with HBV(+), HCV(+), alcohol consumption >20g/day, and steatogenic drugs in the history, were excluded. Statistical analyses were performed with SPSS 15.0 software. Results: AST (25.3±13.7 U/l) was higher than normal in 9%; ALT (36.4±22.9 U/l) higher than normal in 36%, GGT (36.9±25.4 U/l) higher than normal in 19%; AST/ALT ratio (0.80±0.33) was > or = 0.80 in 43% of the patients. HOMA-IR (4.08±2.05) was >2.5 in 77% pts. NAFLD Fibrosis score ranged from -3.98 to +2.04 and in 49% it was < -1.455 (the low cutoff score, excluding fibrosis); in 9% pts it was > +0.676 (the high cutoff score = advanced fibrosis); in 42% pts it was “indeterminate” (> -1.455 and < 0.676). HOMA-IR correlated with ALT (r = 0.42, p<0.001). FS did not correlate with HOMA-IR. However all the patients, with FS higher than the low cutoff score, showed HOMA-IR >2.5. Conclusions: Our results confirm the pivotal role of IR in NAFLD. ALT can be really considered a sensitive marker of liver damage in NAFLD. The Fibrosis Score is a simple scoring system that would be able to predict the advanced liver fibrosis. However it needs further investigations to be validated.
THE NAFLD FIBROSIS SCORE, LIVER ENZYMES AND INSULIN RESISTANCE IN A GROUP OF OBESE AND SEVERELY OBESE PATIENTS
RICCI, Giorgio;ALVISI, Vittorio
2009
Abstract
Background and aim: In obesity, nonalcoholic fatty liver disease (NAFLD) is mostly associated with insulin resistance (IR). Even a slight increase of liver enzymes highlights the hepatic injury. IR also induces liver fibrosis leading progressively NAFLD to cirrhosis. Angulo et al. (2007) suggested a noninvasive simple scoring system that may predict the risk of fibrosis in NAFLD patients: the NAFLD fibrosis score. The aim was to investigate the values of IR by Homeostasis Model Assessment (HOMA-IR), aspartate transaminase (AST), alanine aminotransferase (ALT), gamma glutamyltranspeptidase (GGT), and the NAFLD Fibrosis Score (FS) in obese and severely obese patients. Material and methods: From Jan. to Nov. 2008, 84 obese patients (age 18-68 y; F 60; BMI 31-54 kg/m2), were consecutively selected after admission to our Gastroenterology Unit for the bariatric therapy assessment. Clinical and laboratory data were collected. IR was calculated by the Homeostasis Model Assessment (HOMA-IR), as fastingserum insulin (µU/ml) × fasting plasma glucose (mmol/l)/22.5; values >2.5 indicate a state of IR. The FS was determined by six variables as previously suggested (>-1.455 = possible liver fibrosis). Patients with HBV(+), HCV(+), alcohol consumption >20g/day, and steatogenic drugs in the history, were excluded. Statistical analyses were performed with SPSS 15.0 software. Results: AST (25.3±13.7 U/l) was higher than normal in 9%; ALT (36.4±22.9 U/l) higher than normal in 36%, GGT (36.9±25.4 U/l) higher than normal in 19%; AST/ALT ratio (0.80±0.33) was > or = 0.80 in 43% of the patients. HOMA-IR (4.08±2.05) was >2.5 in 77% pts. NAFLD Fibrosis score ranged from -3.98 to +2.04 and in 49% it was < -1.455 (the low cutoff score, excluding fibrosis); in 9% pts it was > +0.676 (the high cutoff score = advanced fibrosis); in 42% pts it was “indeterminate” (> -1.455 and < 0.676). HOMA-IR correlated with ALT (r = 0.42, p<0.001). FS did not correlate with HOMA-IR. However all the patients, with FS higher than the low cutoff score, showed HOMA-IR >2.5. Conclusions: Our results confirm the pivotal role of IR in NAFLD. ALT can be really considered a sensitive marker of liver damage in NAFLD. The Fibrosis Score is a simple scoring system that would be able to predict the advanced liver fibrosis. However it needs further investigations to be validated.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
