Should we do an oral glucose tolerance test in hypertensive men with normal tasting blood-glucose?

The objective of this study was to examine, using the new WHO criteria for diabetes mellitus, whether insulin and glucose before and after an oral glucose tolerance test would predict cardiovascular mortality in hypertensive men with normal fasting blood glucose. A standard oral glucose challenge was performed after an overnight fast in 113 hypertensive men with either hypercholesterolaemia or smoking. These patients were recruited from an on-going risk factor intervention study. The mean observation time was 6.3 years, During follow-up there were 10 cardiovascular deaths. The Cox regression analyses showed an independent and significant association (P < 0.05) between blood glucose 120 min after the glucose ingestion and cardiovascular death during follow-up. Fasting glucose, fasting insulin and insulin 120 min after glucose ingestion was not related to cardiovascular death during follow-up. In conclusion, this is the first study using the current definition of diabetes mellitus showing that hyperglycaemia following an oral glucose load is an independent risk factor for cardiovascular death in hypertensive men with a normal fasting glucose. In this type of hypertensive patient with normal fasting glucose, an oral glucose tolerance test may help to identify subjects at high cardiovascular risk.