Does insulin resistance participate in an impaired glucose tolerance in primary aldosteronism?
It has been reported that glucose intolerance is occasionally found in primary aldosteronism. In this study, we measured insulin sensitivity by the euglycaemic hyperinsulinaemic glucose clamp technique and ability to release insulin by 75 g oral glucose tolerance test (OGTT) in primary aldosteronism. Seven patients with primary aldosteronism (PA) (53.7 +/- 3.4 years; mean +/- SEM) and eight normotensive subjects (NS) (57.5 +/- 2.6 years) were employed in this study. The two-hour euglycemic hyperinsulinaemic glucose clamp technique was performed in seven PA before adrenalectomy, six PA after adrenalectomy and eight NS. The 75 g OGTT was also done in five PA before and after adrenalectomy and eight NS. The mean rate of glucose infusion to maintain euglycemia for the last 30 minutes of the clamp technique was used as an indicator of insulin sensitivity (M-value). The total blood glucose levels during 75 g OGTT (area under the curves) (sigma blood glucose) were significantly higher in PA t