Insulin resistance and diabetes in the context of treatment of hypertension.

Diabetes is emerging as a new epidemic world-wide because of the ageing of the population but changes in lifestyle are also contributing. All means to prevent this development should be undertaken. In this context, treatment of hypertension is of importance due to the large number of people treated with antihypertensive drugs, many of which interfere with glucose metabolism. In three prospective cohort studies, treatment with beta-blockers and diuretics has been associated with an increased risk of development of diabetes. Prospective, randomized studies with antihypertensive drugs have demonstrated differences between different classes of drugs regarding effects on insulin sensitivity. Thus, treatment with beta-blockers or high-dose diuretics is associated with impairment in insulin sensitivity, whereas most modern calcium-channel blockers and angiotensin converting enzyme (ACE) inhibitors are neutral. However, there are exceptions within the different classes. Captopril differs from the other ACE inhibitors and results in improvement of insulin sensitivity. The most pronounced improvements have been obtained with alpha1-blockers. In a recent study, the data indicate that also moxonidine, an imidazoline1 receptor agonist, is effective in lowering blood pressure and improving insulin sensitivity in insulin-resistant patients. In populations at high risk for diabetes, it may be justified to select drugs that improve insulin sensitivity when treating hypertension in insulin-resistant individuals.