Misclassification of diabetic subjects may account for the increased vascular risk of impaired glucose tolerance: the Islington Diabetes Survey

Durability of glycemic control: a feature of the thiazolidinediones

Type 2 diabetes is a rapidly growing disorder that affects millions of Americans. It usually results from a combination of insulin resistance and a beta-cell secretory defect leading to hyperglycemia and microvascular and macrovascular complications, including cardiovascular disease. With the increasing number of options available for the treatment of type 2 diabetes, it can be difficult to determine which medication to prescribe for each patient. Ideally, an agent that effectively lowers glucose concentrations while also minimizing disease progression should be chosen. The thiazolidinediones (TZDs), a relatively newer class of antidiabetic agents, have been shown to be efficacious in lowering glucose concentrations, maintaining glycemic control, and improving other cardiovascular risk factors. These include reduction of visceral adiposity, alteration of lipoprotein concentrations with a favorable distribution of cholesterol subfractions, and decreasing markers of inflammation and endothelial dysfunction. Overall, the TZDs appear to be a promising therapeutic option for consistent control of glucose levels and may slow the progression of type 2 diabetes.

Risk factors for vascular disease in patients with diabetes

The risks of cardiovascular and cerebrovascular disease in patients with diabetes are greater than those in persons without diabetes. This is due, in part, to the metabolic effects of insulin resistance. Other contributing factors include hyperglycaemia, dyslipidaemia, hypertension, hypercoagulability, homocysteinaemia, smoking, and obesity. Risk factor modification, where possible, can reduce the risk of complications of diabetes and macrovascular disease.

A comparison of the relationships of the glucose tolerance test and the glycated haemoglobin assay with diabetic vascular disease in the community. The Islington Diabetes Survey

We have compared the relationships of fasting and 2 h blood-glucose during a 75 g oral glucose tolerance test, and those of an affinity chromatography assay of glycated haemoglobin, with the presence of vascular complications of diabetes mellitus in 223 subjects without known diabetes aged over 40 years selected from a community screening study population. The subjects included 15 (6.9%) with newly diagnosed diabetes and 52 (24.1%) with impaired glucose tolerance. Employing receiver operating characteristic analysis, the tests were similar in their relationship with three cases of retinopathy, 19 of microalbuminuria and six of peripheral neuropathy. The prevalence of coronary heart disease, defined as angina, myocardial infarction, or electrocardiographic changes of ischaemia, increased linearly across all four quartiles of both 2 h blood glucose and glycated haemoglobin concentration, but using logistic regression analysis, 2 h blood glucose was a better predictor of coronary heart disease than glycated haemoglobin. Receiver operating characteristic analysis also showed that 2 h blood glucose generally performed better than any of four assays of glycated haemoglobin in classifying those subjects with coronary heart disease.