Glucose: a continuous risk factor for cardiovascular disease.

The glucose level that defines diabetes mellitus is that level above which patients have a high risk of eye, kidney, and neuronal disease. The risk of these complications rises as glucose levels increase, and decreases as therapy brings the glucose level down. Thus, in patients with diabetes, glucose is a continuous, modifiable risk factor for eye, kidney and peripheral nerve disease. Plasma glucose concentrations in the diabetic range are also a continuous risk factor for cardiovascular disease (CVD). Moreover, epidemiological evidence shows that the relationship between plasma glucose concentration and CVD extends well below the glucose level defined for diabetes and even impaired glucose tolerance. This continuous relationship between glucose and CVD exists in all people, not just in those with a defined metabolic disease, and is therefore similar to the relationship between cholesterol or blood pressure and CVD. It may be secondary to either a direct effect of elevated glucose or to some underlying metabolic abnormality that raises both glucose and cardiovascular risk. Whether interventions that lower glucose will also lower the risk of CVD is still unknown; the results of clinical trials are awaited.