Hypertension and diabetes: should we treat early surrogates? What are the cons?

Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease

The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.

Evidence that prehypertension is a risk factor for Type 2 diabetes

Whether or not blood pressure categories below 140/90 mmHg are associated with incident Type 2 diabetes or cardiovascular disease is subject to debate. Currently, a blood pressure of 120-139/80-89 mmHg is recognized as prehypertension. This article evaluates the association of prehypertension with incident Type 2 diabetes in the San Antonio Heart study. The authors found that prehypertension in the entire cohort was not related to incident Type 2 diabetes in fully adjusted analyses, but that a blood pressure of 130-139/85-89 mmHg was related to incident diabetes. These results, and conclusions of other studies, suggest that the prehypertension category should be divided for diabetes risk assessment.