Lifestyle: Hypertension epidemic: Silent global killer

A research paper published in 2014 by Williams et al titled “Silent Crisis; Epidemic Hypertension in Rural Ghana” indicated that one out of two (50.9%) adults living in a developing country like Ghana have hypertension and more than one quarter (25.8%) of those diagnosed previously were not on treatment for hypertension. This is alarming and on this background that this article is written to create awareness and sensitization. In the United States, about 85 million adults representing 1 out of 3 adults have high blood pressure and only about half of these adults have their condition well managed (1).

In 2000, 972 million people had hypertension globally, in 2010 more than 1.3billion people were living with hypertension representing about 5.3% of the world population, the number is estimated to double by 2025 if no intervention is put in place. Nearly two-thirds of hypertensives live in low and middle-income countries like Ghana, resulting in a huge economic burden (2).

Hypertension is a global health crisis due to its high incidence and prevalence rate and it is a primary modifiable risk factor for stroke, myocardial infarction, vascular diseases and chronic kidney diseases and a major cause of preventable premature death. A WHO report in 2002 identified hypertension as the third-ranked factor for disability-adjusted life and now the leading causes of death worldwide, but many people with hypertension are not diagnosed and not on treatment (3).

Definition and Classification

Hypertension also referred to as Systemic Arterial Hypertension is defined as blood pressure higher than 130/80 mmHg according to the new guidelines issued by the American Heart Association (AHA) in November 2017 (4).

Normal: Less than 120/80 mmHg

Elevated: Systolic between 120 -129 and diastolic less than 80

Stage 1: Systolic between 130-139 or diastolic 80-89

Stage 2: Systolic more than 140 and diastolic more than 90

Hypertension may be classified as primary, which may have an environmental or genetic aetiology or secondary which has various etiological causes such as renal, vascular, and endocrine. Primary also referred to as essential hypertension accounts for 90-95% 0f adult cases and secondary hypertension accounts for 2-10% of the cases. Isolated hypertension is more prevalent in the elderly population as diastolic blood pressures mostly plateau in the 5th and 6th decades and gradually declines. Severe cases of hypertension i.e. BP higher than 180/ 120 mmHg can also be classified as Hypertensive Urgency or Emergency if there is evidence of end-organ damage. Hypertensive disorders during pregnancy have high morbidity and mortality on both mother and unborn baby and can be further classified as chronic hypertension, preeclampsia, eclampsia and preeclampsia superimposed on chronic hypertension (3).

Diagnosis

Hypertension can be diagnosed after accurate measurement of the patients’ blood pressure on three separate occasions with the average of 2 taken on each of the visits and taking a detailed history and physical examination with evaluation of

End-organ damage (eg, heart, brain, kidneys and eye)

Cardiovascular risk factors

Any evidence of secondary cause of hypertension

Cardiovascular Risk Factors

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7) has identified the following as a major cardiovascular risk factors

Hypertension

Sedentary lifestyle

Tobacco use, mostly cigarette abuse

Obesity (BMI>30kg/m2)

Age greater than 55years for men or 65years for women

Elevated LDL Cholesterol or Total cholesterol or low HDL cholesterol

Estimated glomerular filtration rate less than 60 mL/min

Microalbuminuria

Family history of premature cardiovascular disease

Complication and Target Organ Damage

The common end-organ damage associated with hypertension includes Heart (Left Ventricular hypertrophy, myocardial infarction, coronary artery diseases, and heart failure), Brain (Stroke, Transient Ischemic attacks, and dementia), Chronic Kidney Disease, Peripheral Arterial Disease, Retinopathy etc.

Hypertensive Heart Diseases

Prolonged and uncontrolled high BP can cause changes in the heart muscles, coronary vessels and the conduction system of the heart. This can cause heart diseases such as left ventricular failure, coronary artery disease, arrhythmias, selective systolic or diastolic malfunctions, angina and myocardial infarctions, cardiac arrhythmia mostly atrial fibrillation, and congestive cardiac failure collectively called hypertensive heart diseases (3).

Hypertension and Cerebrovascular disease

Hypertension is the highest risk factor for ischemic strokes and intracranial haemorrhage, prolonged and uncontrolled hypertension can cause hemorrhagic and atheroembolic strokes or even encephalopathy. BP recording of more than 160/100 mmHg is associated with a high incidence of stroke. There is strong evidence linking uncontrolled hypertension with declined cognitive function and dementia

Hypertension and CKD

Hypertension has been closely associated with CKD with intertwined causative effect on each other. A prolonged and uncontrolled hypertension worsens kidney functions whiles kidney diseases are associated with high blood pressure. Cohort studies consisting of 3612 adults with CKD reviewed 86% prevalence of self-reported HTN as against 29% in a general population. Other studies have shown poor BP control in advance CKD (5).

Hypertension and Vascular Diseases

Peripheral Vascular disease PVD has a high incidence of hospitalization in the USA (9.6%) representing about 63000 hospital admission every year. It is a cause of significant morbidity and mortality. Hypertension is a significant risk factor for all vascular diseases. 2-5% of patient presenting with hypertension had intermittent claudication.

Hypertension also contributes to the pathogenesis of atherosclerosis by hardening and thickening of the vessel which is the basic underlying pathological process of PVD. This can also lead to aneurysms. A ruptured aneurysm is an emergency and has a high mortality (6).

Hypertension and Retinopathy

Retinopathy is considered one of the indicators of target organ damage. Poorly controlled systemic hypertension causes damage to the retinal microcirculation, so that recognition of hypertensive retinopathy maybe important in the assessment of cardiovascular risk in hypertensive patients (7).

Hypertension and Metabolic syndrome

Metabolic syndrome is complex and multifactorial and it consists of hypertension, obesity, insulin resistance and dyslipidemia. The constellation of these factors mediates changes leading to high blood pressure. Of these factors, obesity may play a vital role in creating the environment for hypertension in metabolic syndrome (8)

Management of hypertension

Many guidelines exist for the management of hypertension. Most associations which include JNC, American Diabetes Association ADA and American Heart Association/ American Stroke Association AHA/ASA recommends lifestyle modifications the first step in managing hypertension. JNC 7 lifestyle modification includes the following

Weight loss (result in a 5-10mmHg reduction for every 10kg lost)

Limiting alcohol intake to not more than 2 units for men and 1 unit for women

Reduced Salt intake to 6g of sodium per day

Maintain adequate intake of dietary potassium (90mmol/day)

Adequate intake of dietary calcium and magnesium for general health

Stop smoking

Aerobic Exercise at least 30 minutes daily

For your medical treatment kindly see a doctor.

Reference

1.SLR. High blood pressure, also known as hypertension, has become a global crisis | | Blogs | CDC [Internet]. [cited 2018 Oct 19]. Available from: https://blogs.cdc.gov/global/2015/05/15/world-htn-day-high-blood-pressure-also-known-as-hypertension-has-become-a-global-crisis/

2.WHO | A global brief on hypertension [Internet]. WHO. [cited 2018 Oct 19]. Available from: http://www.who.int/cardiovascular_diseases/publications/global_brief_hypertension/en/

3.Hypertension: Practice Essentials, Background, Pathophysiology. 2018 Sep 16 [cited 2018 Oct 19]; Available from: https://emedicine.medscape.com/article/241381-overview

4.Flack JM, Calhoun D, Schiffrin EL. The New ACC/AHA Hypertension Guidelines for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Am J Hypertens. 2018 Jan 12;31(2):133–5.

5.Judd E, Calhoun DA. Management of hypertension in CKD: beyond the guidelines. Adv Chronic Kidney Dis. 2015 Mar;22(2):116–22.

6.Makin A, Lip GY, Silverman S, Beevers DG. Peripheral vascular disease and hypertension: a forgotten association? J Hum Hypertens. 2001 Jul;15(7):447–54.

7.Grosso A, Veglio F, Porta M, Grignolo FM, Wong TY. Hypertensive retinopathy revisited: some answers, more questions. Br J Ophthalmol. 2005 Dec;89(12):1646–54.

8.Mulè G, Calcaterra I, Nardi E, Cerasola G, Cottone S. Metabolic syndrome in hypertensive patients: An unholy alliance. World J Cardiol. 2014 Sep 26;6(9):890–907.