Hypertension: A Heart Broken Factor

The heart is a powerful organ, pumping blood to other parts of your body. Sometimes there is an increase in pressure when the blood pushes against the walls of your arteries. When the pressure is too forceful, will it lead to a broken heart...

There are racial health disparities in the treatment and management of hypertension (read about hypertension treatment). It is crucial to prevent these disparities by implementing a tailored approach to consider the patient’s environment, lifestyle and genetics.

Hypertension is highly prevalent in people of African descent. African Americans tend to develop high blood pressure at a young age.1 Potential determinants of hypertension in the black population include obesity, low levels of plasma renin, higher salt sensitivity, abnormal vascular function, genetic predisposition, and positive family history.2 Individuals tend to retain salt, which appears to be controlled via a renal mechanism.3 On account of a higher capacity to retain salt, hypertension tends to be more severe and uncontrolled. Therefore, a thiazide diuretic as initial therapy is more effective because it inhibits the Na+Cl- co-transporter in the distal convoluted tubule of the kidney, blocking sodium reabsorption, leading to a reduction in arterial pressure.4

Many studies conclude that individuals of African ancestry have enhanced adrenergic vascular reactivity and vasodilatory impairment.5 The proposed mechanism is due to endothelial dysfunction induced by a decrease in nitric oxide bioavailability.6,7 An impairment in the dilation of blood vessels leads to an increase in blood pressure. In the large cohort study, Atherosclerosis Risk in Communities (ARIC), greater carotid arterial stiffness was observed in African Americans, resulting in higher blood pressure in the arteries.8,9 Calcium channel blockers effectively lower the blood pressure by the vasodilation on the smooth muscle layer of resistant arteries, counteracting the vascular dysfunction observed in African Americans. 10

Predisposition to hypertension by low levels of plasma renin (a protein secreted by the kidney that regulates blood pressure) mediates the increase in angiotensin II. As a result of the vasoconstriction stimulated by angiotensin II, inflammation occurs in the kidney.11 Therefore, the suppressed renin-angiotensin system (RAS) in the black population affects their tolerance of specific drug classes. Antihypertensive agents such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are avoided as first-line therapy.

Psychosocial stress is also a primary contributor to uncontrolled hypertension. African Americans may experience social anxiety disproportionately compared to other ethnic backgrounds due to racism in the U.S.12 Furthermore, socioeconomic factors such as unemployment, poverty, and poor access to health care can exacerbate the stress. Consequently, medication non-adherence and improper management increase the risk of complications such as kidney damage and stroke. African American patients represent a high-risk population with a high incidence of cardiovascular diseases (stroke, heart attack) and end-stage renal disease.13 The management of high blood pressure for African Americans is incredibly complex; to find only one underlying factor means to search for a “needle in a haystack.” Without the optimal care and treatment of this disease in the black population, the consequences can be more devastating and harmful, leading to increased morbidity and mortality than other racial groups.

There are multiple obstacles to preventing optimal hypertension treatment in the black population classified by different factors: medication adherence, lifestyle, environment, patients’ support system, proper medical care, and follow-up.13 Therefore, it is recommended to implement a tailored approach to consider their immediate environment and social status. Adequate management of this disease will require a multidisciplinary team and a myriad of measures to enforce medication adherence and lifestyle modifications to effectively lower blood pressure.

The information revealed in this oracle will hopefully rescue those “heartbroken souls.”

References:

1. Ferdinand KC, Townsend R. Hypertension in the US Black population: risk factors, complications, and potential impact of central aortic pressure on effective treatment. Cardiovasc Drugs Ther. 2012; 26: 157-165.

2. Ferdinand KC, Nasser SA. Management of essential hypertension. Cardiol Clin. 2017; 35: 231-246.

3. Brewster LM and Seedat YK. Why do hypertensive patients of African ancestry respond better to calcium blockers and diuretics than to ACE inhibitors and β-adrenergic blockers? A systematic review. BMC Medicine. 2013; 11: 141.

4. Ellison DH. Loffing J. Thiazide effects and adverse effects: insights from molecular genetics. Hypertension. 2009; 54: 196-202.

5. Taherzadeh Z, Brewster LM, van Montfrans GA, VanBavel E. Function and structure of resistance vessels in black and white people. J Clin Hypertens (Greenwich). 2010;12(6):431–8.

6. Mata-Greenwood E, Chen DB. Racial differences in nitric oxide dependent vasorelaxation. Reprod Sci. 2008;15(1):9–25.

7. Vita JA. Nitric oxide and vascular reactivity in African American patients with hypertension. J Card Fail. 2003; 9 (5 Suppl Nitric Oxide): S199–204. discussion S5-9.

8. Din-Dzietham R, Couper D, Evans G, Arnett DK, Jones DW. Arterial stiffness is greater in African Americans than in whites: evidence from the Forsyth County, North Carolina. ARIC Cohort. Am J Hypertens. 2004;17(4):304–13.

9. Hall JL, Duprez DA, Barac A, Rich SS. A review of genetics, arterial stiffness, and blood pressure in African Americans. J Cardiovasc Transl Res. 2012;5(3):302–8.

10. Kahn DF, Duffy SJ, Tomasian D, Holbrook M, Rescorl L, Russell J, Gokce N, Loscalzo J, Vita JA: Effects of black race on forearm resistance vessel function. Hypertension. 2002, 40: 195–201.

11. Price DA, Fisher ND. The renin-angiotensin system in blacks:active, passive, or what? Curr Hypertens Rep. 2003; 5(3): 225–30.

12. Eberly LA, Richterman A, Beckett AG, et al. Identification of racial inequities in access to specialized inpatient heart failure care at an academic medical center. Circ HeartFail. 2019; e006214: 12.

13. Maraboto C. Ferdinand KC. Update on hypertension in African-Americans, Progress in Cardiovascular Diseases. 2020; 63(1): 33–39.

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