Diabetes and Resistant Hypertension: Microvascular Complications

Resistant hypertension is common among patients with type 2 diabetes, and is strongly associated with microvascular disease.

Resistant hypertension—elevated blood pressure unresponsive to 3 medications from different drug classes—places patients at considerable risk for cardiovascular complications. Several conditions seem to be related to resistant hypertension, including overactive adrenal glands, fluid retention and patient nonadherence. Some experts suggest that resistant hypertension is often severe white coat hypertension. Regardless, it’s a particular problem for patients with type 2 diabetes because their risk for cardiovascular disease is already high, but poorly understood in patients with comorbid resistant hypertension and diabetes.

The Journal of Hypertension has published a cross-sectional analysis complied by a team of Italian investigators that describes resistant hypertension’s correlation with diabetes and associated complications.

Using a cohort from the Renal Insufficiency and Cardiovascular Events (RIACE) study (N=15,773), the researchers identified 2,363 patients who met the criteria for resistant hypertension. It’s worth mentioning that this represented 15% of the entire RIACE population, a study that enrolled only patients with type 2 diabetes mellitus during 2007-2008. This indicates that resistant hypertension is relatively common in patients with type 2 diabetes.

Compared to patients with nonresistant hypertension, patients with resistant hypertension tended to be older and female. They also had significantly larger waist circumferences, and were more likely to have albuminuria and laboratory work indicating some renal impairment. They also had more indicators of retinopathy.

Patients who were treated with antihypertensives and controlled appeared to have a greater risk of macrovascular disease, and especially myocardial infarction.

Previous studies have suggested that association between resistant hypertension and waist circumference probably occurs because adipocytes produce an as-yet unidentified mineralocorticoid-releasing factor that stimulates adrenal production of aldosterone, which may cause or contribute to metabolic syndrome. The investigators indicated that their research’s most significant finding is resistant hypertension’s very strong relationship to microvascular complications.