This blog is the 1st in a series of 5 on the topic of metabolic syndrome risk factors.
High blood pressure (hypertension) is one of the main risk factors for cardiovascular disease as well as one of the five diagnostic criteria for metabolic syndrome, as discussed in the previous blog. Blood pressure has two components: systolic blood pressure - the top number representing the pressure generated when the heart pumps blood to the rest of the body - and, diastolic blood pressure - the bottom number representing the pressure in blood vessels between heartbeats.
High blood pressure is diagnosed when one or both of these numbers are elevated above a certain threshold as outlined below:
Hypertension very often causes no symptoms and is typically diagnosed following routine blood pressure monitoring. Very high blood pressure can sometimes cause headaches, fatigue or visual symptoms, the vast majority of people living with high blood pressure have no symptoms at all. This highlights the importance of getting your blood pressure checked regularly and accurately. An accurate blood pressure reading requires manual measurement, following a few minutes of seated rest, with an appropriately fitted cuff and seated with legs uncrossed, back to the chair and arm at heart level. An average measurement needs to calculated from several daily readings over a period of days.
Despite being typically asymptomatic, hypertension silently damages many of our organs, especially our brains, kidneys and heart, due to the mechanical force it produces when flowing through blood vessels. Healthy arteries are flexible, elastic and strong with a smooth inner lining so as to allow blood to flow seamlessly to all our organs and tissues, supplying them with oxygen and vital nutrients. When blood pressure is chronically increased this leads to damage of this inner arterial wall which in turn limits / disrupts blood flow throughout the subsequent part/s of the body. So if, for example, it is the coronary arteries which are damaged by the high blood pressure, they will have trouble supplying blood to the heart, which can lead to angina, arrhythmia or heart attacks (death of the heart muscle). If this damage occurs within the arteries supplying blood to the brain it may cause a stroke or cognitive impairment.
This sort of damage typically develops over the course of many years due to undiagnosed chronic high blood pressure. Ageing and having a family history of hypertension increases your risk of having high blood pressure. However there are several lifestyle factors which are modifiable and which have a big impact on preventing and/or reducing high blood pressure.
Weight loss has possibly the most profound effect on lowering high blood pressure - an approximate reduction of 1 mmHg with every 1 kg of weight lost.
Exercise - particularly endurance exercise - is also very effective at reducing blood pressure if done consistently. This would typically include doing some sort of aerobic exercise such as brisk walking or cycling for a long duration at an intensity which elevates your heart rate slightly but at which you may still hold a conversation.
Eating a healthy diet, and specifically reducing your salt (sodium) intake, is also conducive to lowering blood pressure. The DASH (Dietary Approaches to Stop Hypertension) diet is an eating plan which helps reduce or prevent hypertension. It focuses on vegetables, fruits, wholegrain, beans, nuts as well as lean protein such as poultry and fish whilst limiting foods which are high in salt, have added sugar or are high in saturated fat. Lowering salt intake is at the centre of this eating plan - choose fresh, whole foods; eat home cooked meals more often; avoid packaged foods; read food labels; experiment with spices and herbs in place added salt.
These three lifestyle changes also impact insulin resistance and help avoid type 2 diabetes which in turn reduces high blood pressure.
Chronic stress and sleep deprivation are all known to drive up blood pressure. Establishing good sleep hygiene and managing our stress levels consistently all help in maintaining a healthy blood pressure.
These lifestyle factors, collectively, have the potential to reduce blood pressure with the same potency as a pharmacological alternative, but without the possibility of side effects. Nevertheless, there are cases in which drugs are necessary to treat hypertension. There are currently four classes of antihypertensive medications:
Calcium channel blockers
Angiotensin-receptor blockers (ARBs)
Angiotensin converting enzyme (ACE) inhibitors
It is estimated that about a third of the global adult population is currently living with high blood pressure. Living a healthy lifestyle may help prevent developing high blood pressure as well as cure elevated blood pressure in certain cases. Drugs may be prescribed on top of this in more severe cases - individuals will respond differently to different combinations of treatments and it is important to monitor regularly as you may also drive your blood pressure too low, which is also undesirable.