Angiotensin II enhances insulin sensitivity in healthy volunteers under euglycemic conditions

Abstract

It has been postulated that vasoconstrictors cause insulin resistance. This effect has been documented for epinephrine but not for angiotensin II (Ang II). The aim of this study was to investigate the effect of the latter on insulin sensitivity. In order to study the influence of subpressor doses of Ang II on insulin-mediated glucose uptake under euglycemic conditions, eight healthy volunteers were allocated in random order to sham infusion or infusion of Ang II (first 0.75 ng/kg per min and subsequently 1.5 ng/kg per min). In addition, in seven of the subjects Ang II was infused after 3 days of indomethacin pretreatment (150mg/day). Insulin-mediated glucose uptake (expressed as M value) was measured with the euglycemic clamp technique. Insulin levels were measured enzymatically, plasma renin activity, Ang II, aldosterone and C-peptide levels by radioimmunoassay, blood pressure by Dinamap and muscle blood flow by plethysmography. The M value after sham infusion was 7.81 ± 1.52mg/kg per min and after 1.5 ng/kg Ang II per min was 9.76 ± 1.26mg/kg per min (PConclusions: Ang II increases insulin-mediated glucose uptake: that is, it enhances insulin sensitivity by mechanisms independent of prostaglandins. The observations are of potential relevance to the changes in insulin sensitivity in some forms of hypertension.