Acute effects of nicorandil on glucose tolerance in subjects with borderline fasting blood glucose levels

The acute effect of the anti-ischemic potassium channel opener nicorandil on glucose tolerance and post-challenge insulin levels was investigated in 11 subjects (6 males and 5 females, age 59 +/- 2 years) with borderline fasting blood glucose in a single blinded randomised study. All participants were submitted to two oral glucose tolerance tests in randomised order, once without any premedication and once 30 minutes after oral administration of 20 mg nicorandil. This single dose of nicorandil significantly increased blood glucose levels at 120 minutes (173 +/- 16 vs. 150 +/- 11 mg/dl, p < 0.05 by ANOVA) and 180 minutes (106 +/- 11 vs. 88 +/- 7 mg/dl, p < 0.05 by ANOVA) after ingestion of 75 mg of glucose. Serum insulin levels were not significantly altered. In conclusion we suggest that controlled studies in patients with coronary artery disease should be performed to investigate whether long term treatment with nicorandil increases progression rates from impaired glucose tolerance to type-II diabetes and/or from normal to impaired glucose tolerance with a possibly negative impact on the course of cardiovascular disease in comparison to conventional anti-anginal drugs.