Epidemiological data on postprandial glycaemia

Abstract

There are few studies on the effects of postprandial hyperglycaemia, and usually it is assumed that its effects are the same as those of post-glucose-load hyperglycaemia, following a standard 75 g oral glucose tolerance test. There is some evidence from a study with blood drawn following ingestion of a standardised "diabetes screening product" or a 75 g oral glucose load, that the glucose concentrations during the 2-hour period of these two tests are highly correlated. There is epidemiological evidence that the 2-hour post-load-glucose is more predictive of cardiovascular mortality than fasting glucose, but it would appear that they are equally predictive of retinopathy. While hyperglycaemia is related with cardiovascular mortality, clinical trials lowering glucose levels in type 2 diabetic patients, have not succeeded in reducing cardiovascular disease rates, in contrast to the beneficial effects on micro-vascular disease. STOP-NIDDM, a clinical trial testing the prevention of type 2 diabetes, used the glucose lowering agent acarbose, a drug which lowers postprandial glucose. There was a beneficial effect on cardiovascular outcomes, however, the number of events was extremely small and the study was not designed to test this effect. Confirmatory studies are required before it is possible to conclude that acarbose is effective in cardiovascular prevention, and that indeed it is the treatment of postprandial glucose which is beneficial. The cardiovascular disease in diabetic patients may be due to the presence of other cardiovascular risk factors associated with diabetes.