Onyekachi Ifudu
Hypertension is common in Nigerians and indeed in people of African descent wherever they reside. Despite the availability of a wide variety of antihypertensive drugs, poorly controlled hypertension is the single largest risk factor for organ damage. This is not just a consequence of socio-economic deprivation, because even in countries that subsidize medications, hypertension control rates remain poor.
What is Blood Pressure
Blood pressure (BP) is the pressure of the blood against the walls of the arteries when the heart pumps blood into the arteries. Normal BP is below 120/80 mmHg. The top (systolic) is the pressure when the heart contracts to pump blood into the arteries, and the bottom number (diastolic), is the pressure when the heart relaxes between beats. Both numbers are equally important. When BP is high and untreated, it can damage blood vessels in various organs in the body.
What are the types of Hypertension
There are two types of hypertension. Primary hypertension – also known as essential hypertension refers to hypertension that has no known cause. Over 90% of people who have hypertension have primary hypertension.
Secondary hypertension is when there is an identifiable and potentially reversible cause of hypertension. Less than 10% of hypertension is the secondary type and it is more prevalent in younger people. Some of the causes of secondary hypertension include high levels of hormones that control BP, narrowing of arteries that supply blood to the kidneys, side effects of medications like birth control pills and diet pills.
Why is hypertension common in people of African descent – The “thrifty gene” hypothesis
Researchers don’t have a definitive explanation, but it may be due to genetic factors. It has been theorized that people of African descent possess a gene – a thrifty gene for sodium – that enabled their kidneys to excessively reabsorb and conserve sodium in the hot, dry climate of Africa to avoid dehydration.
However, as people migrated out of Africa to cooler climates, they carried this gene with them, resulting in sodium avidity that leads to hypertension especially in societies where salt is abundant in foods.
Also, research shows that there may be a gene that makes people of African descent more salt sensitive. In people who have this gene, as little as half a teaspoon of salt could raise BP by 5 mmHg. Furthermore, even among persons of African descent with normal BP, when given an equivalent amount of salt, their BP rises higher, and their body retains more of the administered salt compared to white persons.
Harmful effects of Hypertension – No organ is spared
Hypertension usually has no symptoms. Organ damage goes on quietly without the individual having any symptoms (silent killer), until a catastrophic event occurs. Hypertension may cause heart failure, stroke, heart attack, kidney failure, abnormal heart rhythm, death, eye disease and erectile dysfunction.
How is Hypertension treated–Drug therapy and Nondrug therapy
Broadly there are two approaches to treat hypertension and both are complementary to each other. Your doctor decides on what drug is ideal for you based on factors like cost, side effects, gender, age and any coexistent conditions like diabetes, heart failure or prostate enlargement.
Nondrug therapy of hypertension (also called lifestyle modification) involves the implementation of the following interventions:
Dietary salt restriction
Maintaining ideal weight
3) Aerobic exercise
4) Reducing alcohol intake
5) DASH (Dietary Approaches to Stop Hypertension) diet – which consists of increased intake of fruits, vegetables, low-fat dairy products combined with salt restriction
6) Smoking cessation, adequate potassium intake, avoidance of nonsteroidal anti-inflammatory drugs
7) Good sleep hygiene
8) Vitamin D supplementation in those with vitamin D deficiency
Treatment of Hypertension – Why are we failing
Proper treatment of hypertension significantly reduces the risk of organ damage. However, proper treatment of hypertension MUST include “nondrug” therapy. Failure to aggressively employ the above-listed “lifestyle modifications” is the most important explanation for why a large proportion of treated hypertensive patients fail to achieve the desired BP.
This is because the ability of antihypertensive drugs to normalize your BP long-term is dependent on strict adherence to the “lifestyle modifications”. For example, even if you achieve normal BP initially by taking multiple BP medications, and you fail to simultaneously reduce salt intake, after a while your BP will begin to rise again.
The effectiveness of nondrug interventions is well established ─ but, the challenge is that doctors don’t emphasize them enough, and many patients lack the discipline to stick to them. Therefore, it becomes rather convenient to just prescribe drugs.
Other measures that will improve hypertension control is to appreciate that in persons with moderate to severe hypertension, no single drug covers for 24 hours – stagger treatment throughout the day to achieve round-the-clock coverage.
Also, in persons with moderate to severe hypertension and in people of African descent, a diuretic (water pill) is essential to enhance salt excretion – especially since the body reflexly begins to retain salt after the initial lowering of BP with drugs.
Common myths in hypertension
“I can’t have hypertension because there is nothing am thinking about or nothing is bothering me”. Thinking or being bothered by something is not the issue – hypertension is very common in people of African descent.
“My BP is not high because I don’t have any symptoms”. In general, there are no symptoms attributable to hypertension – you will have symptoms once it has damaged your organs.
Primary hypertension is a lifelong condition, so most patients will need BP control for life. However, achievement of normal BP by strict adherence to lifestyle modification measures would permit reduction in the number or dose, or infrequently, discontinuation of antihypertensive drugs.
Treating Hypertension – The way forward
Meticulous adherence to lifestyle modifications to control hypertension is not just effective, but also saves money by reducing the number or dose of antihypertensive medications that the individual requires. While individuals are ultimately responsible for adherence to lifestyle modification measures, many countries are implementing policies at the national level to combat hypertension.
Countries that have implemented a hypertension awareness initiative, reduction of salt intake strategy and aerobic exercise by prescription program at a national level, have witnessed a dramatic improvement in BP control, as well as a remarkable reduction in organ damage and deaths from hypertension.
*Dr. Ifudu is board-certified in Internal medicine & Nephrology/Hypertension and is an Adjunct Professor of Medicine at SUNY Downstate, Brooklyn, New York. He graduated from University of Nigeria and Harvard University – did residency training at Columbia University College of Physicians & Surgeons, New York, and fellowship at SUNY Downstate, Brooklyn, New York. A clinician/researcher, Dr. Ifudu is extensively published and has received numerous research grants including support from the National Institutes of Health. He authored a state-of-the-art article in The New England Journal of Medicine on the “Care of Patients Undergoing Hemodialysis”. He has done volunteer work for the National Kidney Foundation in New York, and in 2003 volunteered for six months at the Nephrology unit of the National Hospital, Abuja.
