Abstract

Reducing cardiovascular risk factors in patients with prediabetes

Author(s): Jean-Louis Chiasson & Sophie Bernard

Type 2 diabetes mellitus is generally preceded by a state that has been termed prediabetes, which is defined as impaired fasting glucose and/or impaired glucose tolerance. The prevalence of prediabetes is as high, if not higher, than that of diabetes in most countries, particularly in developing countries. Prediabetes hyperglycemia is now recognized as an independent risk factor for cardiovascular disease. Furthermore, it is usually associated with other cardiovascular risk factors such as obesity, hypertension and dyslipidemia, all features of the metabolic syndrome. We have very few studies that have evaluated the effects of treatment of those cardiovascular risk factors on cardiovascular events and mortality in the prediabetic population. However, we have a number of prospective randomized intervention trials that have evaluated the effects of treatments of hyperglycemia in the diabetic populations, and the effects of treatments of hypertension and dyslipidemia in diabetic and nondiabetic populations. It has been well demonstrated in those populations that treating hypertension with most antihypertensive drugs and dyslipidemia with statins resulted in a significant reduction in cardiovascular events and mortality. However, it has been more difficult to convincingly show that treating hyperglycemia in patients with diabetes reduced cardiovascular events and mortality. A recent meta-analysis does suggest that intensive glycemic treatment is associated with a reduction in nonfatal myocardial infarction and coronary heart disease but does not seem to affect stroke and all-cause mortality. Observational studies also suggest that treating obesity should be associated with a reduction of cardiovascular disease. Since it is recognized that impaired glucose tolerance has the same cardiovascular risk as newly diagnosed Type 2 diabetes, it is proposed that prediabetes should be screened in high-risk populations and all cardiovascular risk factors should be treated similarly to patients with Type 2 diabetes.