Relationships among insulin resistance, type 2 diabetes, essential hypertension, and cardiovascular disease: similarities and differences

Abstract

Insulin resistance plays a major role in the pathogenesis and clinical course of patients with type 2 diabetes (2DM) and essential hypertension. However, the syndromes differ in prevalence of insulin resistance, and associated insulin secretory response. Essentially all patients with type 2 diabetes are insulin resistant, whereas only approximately 50% of those with essential hypertension are insulin resistant. Furthermore, 2DM develops when the pancreatic β-cell can no longer maintain the degree of compensatory hyperinsulinemia needed to prevent hyperglycemia. In contrast, the compensatory hyperinsulinemia that prevents most insulin resistant individuals from developing 2DM acts on normally insulin sensitive tissues in a manner that predisposes to the development of essential hypertension. This review will discuss these similarities and differences in some detail, as well as exploring the relationship among insulin resistance and related metabolic abnormalities in the pathogenesis of cardiovascular disease in patients with 2DM and essential hypertension.

Figure 1

Comparison of the proportion (percent) of untreated and treated patients with essential hypertension in the 3 SSPG categories: <96 mg/dL=most insulin‐sensitive; 96mg/dL–180 mg/dL=intermediate; >180 mg/dL=most insulin‐resistant. Reprinted with permission.²¹

Figure 2

Plasma glucose and insulin concentrations before and after a 75‐g oral glucose challenge in control patients and two groups of patients with essential hypertension with normal or abnormal electrocardiograms (ECGs). Reprinted with permission.³³