Antihypertensive treatment of patients with diabetes and hypertension

Abstract

Whereas individual research papers about antihypertensive treatment in diabetics might be somewhat confusing, the weight of the evidence strongly suggests that: 1) In patients with type 1 diabetes, it is advantageous to use angiotensin-converting enzyme (ACE) inhibitors as primary treatment. 2) In type 2 diabetics, aggressive blood pressure (BP) lowering is warranted and, the calcium antagonist controversy notwithstanding, all drugs appear to be similarly useful in reducing cardiovascular mortality. Specifically, in the Systolic Hypertension in Europe study, compared with placebo, a calcium antagonist dramatically reduced cardiovascular (CV) events in elderly diabetics. The Hypertension Optimal Treatment study showed that, using a calcium antagonist-based regimen, the degree of BP lowering determines the degree of CV event reduction. Furthermore, the United Kingdom Prospective Diabetes Study (UKPDS) did not find a difference in CV events reduction in patients treated with beta-blockers or with ACE inhibitors. In the UKPDS, the effect of BP lowering on reduction in CV events was more substantial than the degree of CV reduction by blood sugar lowering. 3) Both the CAPtopril Prevention Project (CAPPP) and the Heart Outcomes Prevention Evaluation (HOPE) studies found that treatment with an ACE inhibitor may be useful in reducing the incidence of new-onset type 2 diabetes mellitus. 4) Finally, insulin resistance, a precursor of diabetes mellitus and a strong predictor of future CV disease, is differentially affected by antihypertensive treatment. beta-Blockers and diuretics worsen insulin resistance, whereas alpha-adrenergic blockers and central imidazoline binding agents increase insulin sensitivity. The effect of ACE inhibitors and angiotensin blockers may also positively affect insulin resistance, but the results are not uniformly positive. It stands to reason that the differential effect of various drugs on insulin resistance and primary CV events may be clinically relevant particularly in the course of the long-term prevention of mild hypertension. All current trials investigate the effect of the treatment on secondary prevention of CV events among patients with advanced complicated diabetes and hypertension.