Insulin resistance index (HOMA-IR) in the differentiation of patients with non-alcoholic fatty liver disease and healthy individuals.
BACKGROUND
Due to its good correlation to glycemic clamp, HOMA-IR has been widely utilized as insulin resistance index in clinical and epidemiological studies involving non-alcoholic fatty liver disease carriers. However, values used for this parameter have shown large variability.


OBJECTIVE
To identify the HOMA-IR cut value that best distinguishes non-diabetic non-alcoholic fatty liver disease patients from a control group.


METHODS
One hundred sixteen non-alcoholic fatty liver disease patients were studied, diagnosed by clinical, biochemical, and liver image or biopsy criteria, and 88 healthy individuals, without any liver disease and testing for oral glucose tolerance within normality. These groups did not differ in age and gender. All were submitted to oral glucose tolerance test and blood samples were collected for glucose and insulin measurements by immunofluorometric method. HOMA-IR was calculated according to the formula: fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5.


RESULTS
NAFLD patients showed higher insulin, glycemia, and HOMA-IR values than control group, even when excluding glucose intolerant and diabetes mellitus patients by their glycemic curves. HOMA-IR 75th percentile for control group was 1.78 and the best area under the curve index was obtained for HOMA-IR values of 2.0 [AUC= 0.840 (0.781-0.899 CI 95%), sensitivity (Se): 85%, specificity (Sp): 83%] while value 2.5 showed best specificity without important loss in sensitivity [AUC=0,831 (0.773-0.888) Se = 72%, Sp = 94%].


CONCLUSIONS
HOMA-IR values above or equal to 2.0 or 2.5 show enhanced diagnostic value in distinguishing non-alcoholic fatty liver disease carriers from control group individuals.
Salgado
Ana Lúcia Farias de Azevedo
AL
Departamento de Medicina, Disciplina de Gastroenterologia , Universidade Federal de São Paulo, SP, Brazil.
Carvalho
Luciana de
Ld
Oliveira
Ana Claudia
AC
Santos
Virgínia Nascimento dos
VN
Vieira
Jose Gilberto
JG
Parise
Edison Roberto
ER
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005215:Fasting / Q000097:blood; D005234:Fatty Liver / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D015200:Fluoroimmunoassay; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D012016:Reference Values
D001786:Blood Glucose