[Methods of measuring hyperinsulinism and insulin resistance]

The author gives an account of methods used for evaluation of hyperinsulinism and insulin resistance such as: hyperinsulinaemic, euglycaemic and hyper- and hypoglycaemic "clamp", minimal model of glucose and insulin kinetics. They evaluate specially indexes used in clinical practice such as: I/G, (insulin/glucose--the so-called insulinogenic index), the G/I index, (the so-called index of insulin resistance) and the index of C-peptide/IRI, basal and during the oral glucose tolerance test. In epidemiological studies of the prevalence of the X syndrome (5H) he recommends to use the G/I index basal and minimal two hours after a glucose load, along with assessment of C-peptide. It is thus possible to estimate not only insulin resistance but also hyperinsulinism and the ratio of distribution-utilization factors in the development of this hyperinsulinism. Hyperinsulinism need not be only hypersecretory but may be also associated with a reduced insulin utilization in the liver and peripheral target tissues. A hyperinsulinaemic response may be observed in four types of glycaemic curves after a glucose load: a in a normal curve, a flat curve, in impaired glucose tolerance and in a diabetic curve. According to the author the limiting value of the I/G index is 0.4 and the limiting value of the G/I index is 6 when the insulinaemia is expressed in mIU/l and the blood sugar level in mg%. The limiting level of insulinaemia after two hours is 63 mIU/l. The ratio of C-peptide: IRI basal is cca 5:1 after a glucose load 2.5:1 when expressed in moles.(ABSTRACT TRUNCATED AT 250 WORDS)