Cardiovascular drugs as antidiabetic agents: evidence for the prevention of type 2 diabetes

Prevention of type 2 diabetes mellitus to reduce cardiovascular morbidity and mortality: a review of the evidence

J Clin Hypertens (Greenwich). 2009;11:512-519. (c)2009 Wiley Periodicals, Inc.Cardiovascular disease accounts for the majority of deaths in patients with type 2 diabetes mellitus. Lifestyle interventions aimed at weight loss and increased physical activity and therapy with antidiabetic drugs have proven effective in reducing the risk of new-onset diabetes in high-risk individuals. Substantial evidence also suggests that drugs that inhibit the renin-angiotensin system, namely angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, also prolong the time to onset of clinical diabetes. An open question is whether delay of new-onset diabetes with antidiabetic or antihypertensive agents reduces cardiovascular morbidity and mortality. A large ongoing study is investigating whether therapy with an oral antidiabetic drug or an angiotensin II receptor blocker reduces the incidence of new-onset diabetes and cardiovascular events in high-risk patients.

Antihypertensive medications: benefits of blood pressure lowering and hazards of metabolic effects

Blood pressure reduction is associated with significant reduction in adverse cardiovascular outcomes. Certain blood pressure-lowering drugs have adverse effects on glucose homeostasis, and have been associated with the development of both prediabetes and diabetes during use. There is controversy over the significance of diabetes that develops during treatment with antihypertensives and whether the benefits of blood pressure reduction offset the hazards of dysglycemia that can lead to diabetes. Many treatment guidelines have recently undergone revisions to include consideration for the metabolic effects of antihypertensive drugs, particularly in high-risk populations. This review summarizes the data related to the benefits of blood pressure reduction as well as the adverse metabolic effects and new-onset diabetes associated with some medications.

Prevention of diabetes in hypertensive patients: results and implications from the VALUE trial

A growing number of experimental and clinical studies have provided evidence indicating that pharmacological blockade of the renin–angiotensin system (RAS) by either angiotensin-converting enzyme inhibitors or angiotensin type 1 receptor blockers reduces the incidence of new onset type 2 diabetes in subjects with hypertension and/or cardiovascular disease, independently of antihypertensive and cardiovascular protective effects. The beneficial effects of RAS inhibition on the development of diabetes have been largely attributed to improvements in peripheral insulin sensitivity and glucose metabolism. This review focuses on recent experimental and clinical evidence supporting the role of RAS inhibition in the reduction of new onset type 2 diabetes and the mechanisms that may be involved.

Antihypertensive therapy, new-onset diabetes, and cardiovascular disease

Type 2 diabetes mellitus is a worldwide epidemic with considerable health and economic consequences. Diabetes is an important risk factor for cardiovascular disease, which is the leading cause of death in diabetic patients, and decreasing the incidence of diabetes may potentially reduce the burden of cardiovascular disease. This article discusses the clinical trial evidence for modalities associated with a reduction in the risk of new-onset diabetes, with a focus on the role of antihypertensive agents that block the renin-angiotensin system. Lifestyle interventions and the use of antidiabetic, anti-obesity, and lipid-lowering drugs are also reviewed. An unresolved question is whether decreasing the incidence of new-onset diabetes with non-pharmacologic or pharmacologic intervention will also lower the risk of cardiovascular disease. A large ongoing study is investigating whether the treatment with an oral antidiabetic drug or an angiotensin-receptor blocker will reduce the incidence of new-onset diabetes and cardiovascular disease in patients at high risk for developing diabetes.

Prevalence of abnormal glucose metabolism in atrial fibrillation: a case control study in 75-year old subjects

Background

The prevalence of atrial fibrillation (AF) is increasing world wide and amongst factors that aggravate the risk is diabetes mellitus (DM), also in epidemic development.

However, although DM is a potentially modifiable risk factor for AF, few, if any, studies have explored the prevalence of undiagnosed dysglycaemia among subjects with AF or if duration of AF are related to parameters of glycaemia or dysglycaemia prevalence.

Methods

In this case control study, amongst 75-year old subjects with and without AF, the prevalence of dysglycaemia, i.e., impaired fasting glycaemia, impaired glucose tolerance or DM, according to World Health Organisation criteria was assessed by a 75-g oral glucose tolerance test (OGTT).

Results

Prevalence of undiagnosed DM among the 108 subjects (male/female 73/35, BMI 25.4 ± 3.2) without and the 46 (male/female 34/12, BMI 25.3 ± 3.7) with AF (median AF duration five years) where 3.7% and 13.0%, respectively (p = 0.031, Odds ratio (OR) 3.86 (95% Confidence interval [CI]: 1.01, 16.25)) whereas the overall prevalence of dysglycaemia (prediabetes and DM) where similar (respectively 43.5% and 39.1%, p = 0.46, OR 0.83 [95% CI: 0.41, 1.69]). Patients with AF duration ≥ 5 years had however a higher dysglycaemia prevalence (61.1% [DM 22.2%, prediabetes 38.9%]) as compared to AF duration < 5 years (25% [DM 7.1%, prediabetes 17.9%], p = 0.0014, OR 4.7 [95% CI: 1.30, 16.90]) or no AF (p = 0.17, OR 2.04 [95% CI: 0.73, 5.66]). There was also a significant correlation between the duration of AF and HbA1c (r = 0.408, p = 0.005) and fasting glucose levels (r = 0.353, p = 0.016).

Conclusion

AF is associated with chronic hyperglycaemia amongst 75-year old subjects. Prediabetes and DM should be pro-actively assessed if AF duration ≥ 5 years.