Searching for optimal blood pressure targets in type 2 diabetic patients with coronary artery disease

BACKGROUND: Controversies exist regarding the optimal blood pressure (BP) level that is safe and provides cardiovascular protection in patients with type 2 diabetes mellitus (T2DM) and coexistent coronary artery disease. Several new glucose-lowering agents have been found to lower BP as well, making the interaction between BP and T2DM even more complex. METHODS: With the reference to recent literature, this review article describes the potential mechanisms of increased risk of hypertension in T2DM and outlines the possible optimal BP levels based upon recommendations on the management of hypertension by the current guidelines, in combination with our research findings, for type 2 diabetic patients with coronary artery disease. RESULTS: The development of hypertension in T2DM involves multiple processes, including enhanced sympathetic output, inappropriate activation of renin-angiotensin- aldosterone system, endothelial dysfunction induced through insulin resistance, and abnormal sodium handling by the kidney. Both AGE-RAGE axis and adipokine dysregulation activate intracellular signaling pathways, increase oxidative stress, and aggravate vascular inflammation. Pancreatic β-cell specific microRNAs are implicated in gene expression and diabetic complications. Non-pharmacological intervention with lifestyle changes improves BP control, and anti-hypertensive medications with ACEI/ARB, calcium antagonists, β-blockers, diuretics and new hypoglycemic agent SGLT2 inhibitors are effective to decrease mortality and prevent major adverse cardiovascular events. For hypertensive patients with T2DM and stable coronary artery disease, control of BP < 130/80 mmHg but not < 120/70 mmHg is reasonable, whereas for those with chronic total occlusion or acute coronary syndromes, an ideal BP target may be somewhat higher (< 140/90 mmHg). Caution is advised with aggressive lowering of diastolic BP to a critical threshold (< 60 mmHg). CONCLUSIONS: Hypertension and T2DM share certain similar aspects of pathophysiology, and BP control should be individualized to minimize adverse events and maximize benefits especially for patients with T2DM and coronary artery disease.