Insulin resistance quantification by fasting insulin plasma values and HOMA index in a non-diabetic population

BACKGROUND: Our goal was to determine the prevalence of insulin resistance (IR) by means of fasting insulin plasma values and the HOMA index, and to a nalyse the relation of these para. meters with other components of the meta bolic syndrome. SUBJECTS AND METHOD: We studied 292 non-diabetic individuals, aged between 20 and 65 years randomly selected from subjects attending an outpatient car e center (Valencia-Spain-metropolitan area). 97 subjects who lacked clinica l and biological criteria of IR were selected. In addition to calculating t he HOMA index, anthropometric parameters, plasma lipids values, fasting glu cose and insulin plasma levels were measured by standard methods in all sub jects. RESULTS: In the subgroup of 97 subjects without clinical and biological cri teria of IR, we established a diagnosis of IR when the fasting plasma insul in value was greater than or equal to 16.7 mU/I or the HOMA index was great er than or equal to3.8. Cut-off points of the percentil 90th of this subgro up were taken into account. In the whole group, the prevalence of IR (HOMA greater than or equal to3.8) was 31.8%, with a higher frequency in men comp ared to women. CONCLUSIONS: In addition to fasting plasma insulin values and HOMA index, t he best clinical and biochemical indicators of IR were fasting plasma gluco se levels, BMI and triglycerides (TG) plasma values. Thus, the odds ratio f or insulin resistance was 5.9 for a glycemia greater than or equal to 110 m g/dl, 2.6% for BMI greater than or equal to 25 kg/m(2) and 2.2 for triglyce rides greater than or equal to 150 mg/dl.