PLASMA AMYLIN IMMUNOREACTIVITY AND INSULIN-RESISTANCE IN INSULIN-RESISTANT RELATIVES OF PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS

To explore the potential relationship between concentrations of circul ating amylin and the insulin resistance observed in first-degree relat ives of patients with non-insulin-dependent-diabetes mellitus (NIDDM), we studied 40 relatives compared to 35 matched controls. Two newly de veloped immunoassays that measure either non-glycosylated or total amy lin were applied. All subjects were examined by an oral glucose tolera nce test (OGTT) and by a hyperinsulinemic euglycemic clamp (insulin in fusion: 0.6 mU/kg/min). Glucose tolerance was normal in all, but insul in-stimulated glucose uptake (Rd) was diminished in the relatives (p < 0.001). Area under the curves (AUCs) during OGTT for plasma glucose ( p < 0.01) and serum insulin (p = 0.08), but not for plasma total and n on-glycosylated amylin, were higher in relatives versus controls. in b oth groups, inverse correlations were found between Rd and AUC for pla sma total and non-glycosylated amylin (p [all] < 0.05). However, in mu ltiple linear regression analyses, plasma total and non-glycosylated a mylin failed to influence Rd independent of serum insulin and family h istory of NIDDM. In conclusion, this study demonstrated inverse correl ations between Rd and circulating concentrations of plasma total and n on-glycosylated amylin in relatives and matched controls. These data, however, do not support the hypothesis that physiological amylin conce ntration are a major importance for the insulin resistance in relative s of NIDDM patients.