Estudio crítico del HOMA como método de pesquisa de resistencia insulínica en clínica / A critical study of the HOMA test as a screening for insulin resistance

ABSTRACT

Background: The hyperinsulinemic euglycemic clamp is the gold standard to measure directly insulin resistance.Unfortunately, the procedure is technically demanding, expensive and, unsuitable for clinical work. Cliniciansare used to request an HOMA test (Homeostasis Model Assessment) to indirectly assess the presence of insulinresistance given that it is an inexpensive and readily performed test but it has several shortcomings. Aim: To studythe diagnostic performance of the HOMA test as it is done in our country. Material and methods: We selected 32 women aged 32 +/- 2 years and 18 men aged 42 +/- 3 years. Half of them were categorized as insulin resistant by the pancreatic suppression test with octreotide, that is highly correlated with the euglycemic clamp but simpler to perform. Insulin was measured in two different laboratories in Santiago (Barnafi-Krause and Laboratorio deNutrición, Universidad Católica) and HOMA results were calculated using serum fasting insulin and glucose levels.Results: The correlation coefficients between HOMA, calculated using insulin values of both laboratories, and the results of the pancreatic suppression test were 0.45 and 0.55 (p< 0.01). Only six of 25 subjects defined as insulin resistant by the pancreatic suppression test were detected with HOMA. Therefore, the sensitivity of the latter for insulin resistance was 24 percent. However all subjects defined as insulin resistant by HOMA (BK) hadan abnormal pancreatic suppression test. Conclusions: Even though HOMA test was positively correlated with insulin resistance, it had a poor diagnostic sensitivity. Clinicians should be aware that the HOMA test is proneto under-diagnose the presence of insulin resistance.