Strengthening the Case for Global Risk Assessment of Patients With High Blood Pressure

It is widely accepted that chronic high plasma concentrations of glucose and insulin, as a consequence of insulin resistance, is associated with the development of the metabolic syndrome and (in the absence of significant lifestyle modification) progression to type 2 diabetes mellitus. These conditions are frequently accompanied by essential hypertension, due in part to large artery stiffening, which is associated with both hyperglycemia and hyperinsulinemia.1 Current recommendations for the diagnosis and treatment of hypertension give consideration to the global cardiovascular risk of the patient rather than an isolated focus on blood pressure. This approach recognizes that each additional risk factor that is present in the setting of hypertension has a synergistic and compounding adverse effect on cardiovascular outcome.2 Furthermore, insulin resistance itself has also been associated with coronary heart disease in patients with hypertension.3 Certainly then, the presence or absence of insulin resistance among patients suspected of hypertension should be of interest to clinicians. In the current issue of the American Journal of Hypertension, Lima et al.4 screened 126 patients with hypertension for the presence of insulin resistance as well as other cardiovascular risk factors. The modified insulin suppression test was used to determine insulin resistance (steady state plasma glucose >180 mg/dl), and half of all patients were found to meet this criteria, which is a much higher prevalence than previously thought to exist (≤20%). Notably, only 14% of the population were classified as having normal insulin sensitivity (<96 mg/dl). A strength of this study was the use of a validated and dynamic test of insulin resistance, with meaningful cutoff points derived from a large population sample. It is probably for this reason that a higher prevalence was detected when compared to other studies using a less sensitive, but widely used, tool to measure insulin resistance in the fasting state (the homeostasis model assessment of insulin resistance (HOMA-IR)). However, the modified insulin suppression test is invasive, time consuming, and not readily applicable to the clinical environment. It also provides results that markedly differ from other studies that rely on HOMA-IR. What then is the relevance of these findings to the clinical assessment of patients with hypertension? Undoubtedly, the study by Lima et al.4 reveals a high proportion of patients with known or suspected hypertension that have additional cardiovascular risk owing to undetected insulin resistance and, in general, a poor risk profile. Perhaps not unexpectedly, obesity and dyslipidemia (elevated triglyceride, reduced high density–lipoprotein cholesterol) could predict the patients with insulin resistance, and these measures are readily available in most patients under evaluation for hypertension. Further, it is encouraging that antihypertensive therapy (including high use of diuretics) did not appear to have an influence on insulin sensitivity, which is reassuring for clinicians regarding potential impact on glucose homeostasis. Importantly, incident type 2 diabetes may be circumvented through weight loss and regular exercise.5 Accordingly, the work by Lima et al.4 reinforces the need for attention to global risk assessment in patients with high blood pressure, with particular attention to the encouragement of positive lifestyle modification. The authors declared no conflict of interest.