J Korean Soc Hypertens.  2012 Sep;18(3):75-87.

Blood Pressure Variability and Vascular Dysfunction in Essential Hypertension

• Okumura K
• Cheng XW

Abstract

There are several aspects of blood pressure. Clinically, how to best assess blood pressure average and variability is still a matter of the ongoing debate. Besides office blood pressure, we must pay more careful attention focused on hypertension with blood pressure fluctuation. Impaired endothelial function is intimately associated with the development of hypertension and atherosclerosis. In this review, we describe the relation between endothelial dysfunction and hypertension, the effect of gene polymorphism on endothelial dysfunction, the effects of antihypertensive agents and dietary supplementation on impaired endothelial function in hypertension. In order to predict the future atherosclerosis and cardiovascular events in subjects with hypertension, the adequate assessment of endothelial function is one of the most reliable markers. Furthermore, we discuss the close relationship between blood pressure variability and endothelial function. Blood pressure variability during a day or a week is an important, new risk factor for cardiovascular disease and restoring impaired endothelial function might be a target to prevent blood pressure variation and future cardiovascular events.

Keyword

Blood pressure variability; Endothelial dysfunction; Nitric oxide; Nitric oxide synthase type III; Flow-mediated dilation

MeSH Terms

Antihypertensive Agents
Atherosclerosis
Blood Pressure
Cardiovascular Diseases
Dietary Supplements
Hypertension
Nitric Oxide
Nitric Oxide Synthase Type III
Risk Factors
Antihypertensive Agents
Nitric Oxide
Nitric Oxide Synthase Type III

Figure

• 

  Fig. 1 Blood pressure control. Degree of activation, expressed in terms of feedback gain at optimal pressure, of different pressure control mechanisms after a sudden change in arterial pressure. CNS, central nervous system (Modified from Guyton. Circulatory physiology III: arterial pressure and hypertension. Philadelphia, PA: Saunders, 1980, with permission from Saunders).11)

• 

  Fig. 2 Nitric oxide (NO) synthesis and factors affecting bioavailability. NO is synthesized from L-arginine and promotes vasodilation via cyclic guanosine monophosphate (cGMP) production. The production of NO is controlled by a number of stimuli, including shear stress, acetylcholine and bradykinin, and as a consequence, released intracellular calcium induces endothelial NO synthase (eNOS) actvity. L-arginine is converted to L-citrrulline by eNOS with subsequent production of NO. eNOS requires several cofactors, including nicotinamide adenine dinucleotide phosphate (NADPH) and tetrahydrobiopterin (BH4). The bioavailability of produced NO is affected oxidative stress. ROS, reactive oxygen species; FAD, flavine adenine dinucleotide; GTP, guanosine triphosphate.

• 

  Fig. 3 Effect of endothelial nitric oxide synthase polymorphism on endothelial function in the brachial artery in healthy young men (mean age 30.3 years). Endothelial function is expressed by the ratio of flow-mediated dilation (FMD) to flow with glyceryl trinitrate-induced dilation (GTN). SD, standard deviation.

• 

  Fig. 4 Impact of the presence of 894T allele and -786C allele of endothelial nitric oxide synthase polymorphism. Endothelial function is expressed by the ratio of flow-mediated dilation (FMD) to flow with glyceryl trinitrate-induced dilation (GTN). LDL, low density lipoprotein; HMW, high molecular weight; HDL, high density lipoprotein; HOMA-IR, homeostasis model assessment of insulin resistance.

• 

  Fig. 5 Effect of methylenetetrahydrofolate reductase (MTHFR) 677 C > T polymorphism according to the presence of 894T allele of endothelial nitric oxide synthase (eNOS) gene. Flow-mediated dilation (FMD)/glyceryl trinitrate-induced dilation (GTN) is the ratio of FMD to GTN (ref. 41).

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