The symptoms of heart disease may well be silent until the problem is severe – your first warning may be angina or even a heart attack. Therefore, you must seek medical advice if your family history suggests you may be at risk.
A family history of heart disease can load the gun, as we say – with the trigger then being pulled by unhealthy lifestyle choices, like a poor diet, lack of exercise and stress. Let’s consider Andy’s case………..
Andy, a 45-year-old gentleman, presented initially with vertigo, was treated in the ENT (Ear, Nose and Throat) department and given exercises to practise before getting out of bed in the morning. Six months later, he started to have palpitations, headaches, and dizziness. As he was concerned about his family history, he measured his blood pressure at home and found it running high.
He went to his GP and was prescribed a low dose of blood pressure pills. Andy also had slightly raised cholesterol levels, which escalated following a stressful business episode. He was prescribed a cholesterol pill, and his LDL (the bad cholesterol) promptly dropped from 160 to 65.
This was happening in a patient who was fit as a fiddle, with a body fat mass of 9% (athletic level) and a VO2 max at 52 (a high level of fitness.) But, because he carried two risk factors (hypertension and high cholesterol) in addition to a strong family history of heart disease, Andy underwent further investigation.
A CT scan showed a high calcium score (a sign of significant heart disease) at 391, and one coronary artery was found blocked by 30%. A carotid scan revealed 45% of the main carotid artery blockage on one side.
My purpose in this blog is to ask you not to ignore a strong family history of heart disease and seek early medical advice. You can have significant heart disease when, like Andy, you are fit or when you have no symptoms at all. As we say, your genes can “load the gun, and then the environment pulls the trigger.” The genetic risk stays dormant until an environmental trigger brings it to the surface.
Having a family history of a condition naturally increases your risk of developing that condition. The tricky question to answer is whether you have a genuine family history of heart disease or whether you are inheriting the unhealthy family lifestyle that leads to such a problem.
A genuine family history means having one member of your family with heart disease at an early age – a man under 55 or a woman under 65.
Studies have confirmed that the inheritability of heart disease is high (occurring in 40 to 60% of patients), indicating that the genetic influence is most significant in patients who present with early-onset cardiovascular events.
Nature or nurture?
Again, you need to find out what you have inherited – is it a specific genetic condition or just the risk of having heart disease? Familial hypercholesterolaemia (high cholesterol) is inherited because of a fault (or mutation) in one of your genes. If one of your parents had the faulty gene, then you have a 50% chance of having it too. If both parents had it (very rare), this would give you 100% certainty of having it.
But, as we have said, family history is more complex than that, as people usually inherit multiple factors – both in their genes and in their upbringing. So, the risk of heart disease increases significantly when hereditary factors in your genetic make-up (a predisposition to heart problems) are combined with unhealthy lifestyle choices – food, lack of exercise – which themselves may be inherited from your parents.
What could you inherit?
To look at this in more detail, you could inherit faulty genes that switch your body to producing the wrong proteins in your blood, such as Lp(a). Or an accumulation of a toxic chemical such as homocysteine or inheriting a specific genetic variant with a single nucleotide (one unit) of the long genetic code been altered such as MTHFR and APOE.
Some people inherit the genetic tendency for their body to build up the high inflammation and oxidative stress (rusting) necessary for the development of atherosclerosis (clogging of arteries), the hallmark of vascular disease.
For example, a high level of homocysteine is a very common risk factor for heart disease and stroke. This can result from genetic factors or nutrient deficiency, or both. The gene involved in this condition is known as MTHFR, which catalyses the activation of folate, necessary for detoxifying homocysteine (the toxic substance) back into a normal amino acid known as methionine. The homocysteine could also be detoxified via a different route controlled by another gene known as CBS, which also breaks the toxic molecule into a very useful molecule known as glutathione, the master antioxidant.
What do we test for?
At the Vitality Clinic, we routinely test the level of homocysteine in every patient presenting with high blood pressure or heart disease. If we find a high level of homocysteine, we run genetic tests looking for the MTHFR variant. We also test for evidence of folate deficiency (another cause of high homocysteine.) This would help the clinical decision on the treatment – prescribing either ordinary folate or the activated form of folate to lower high levels of homocysteine.
We also test for low-grade inflammation using high sensitivity CRP (hs-CRP), another marker of vascular disease. Hs-CRP should be less than 1.0. We also check for blood sugar regulation and insulin resistance, the core of the vascular disease problem.
We also test for the well-known APOE genetic variant, which increases the risk of dementia and vascular disease. This APOE gene has three components, E2, E3 and E4. E3 is the normal one, whilst E4 increases the risk of dementia. However, the risk of heart disease is driven by both E4 (interferes with LDL – the bad guy) and E2, which increases the risk of clots in the circulation. Both are essential components of acute vascular events.
An elevated level of Lp(a) is a known risk factor for cardiovascular disease, increasing the risk of heart attack and stroke. Lp(a) makes the blood thick and increases the risk of thrombosis (clot formation) and should be tested in any patient with a family history of premature cardiovascular disease.
Genetic tests would also be useful to investigate the presence of pro-inflammatory genes such as interleukin-1A (IL-1A), IL-1B, IL-1RN and TNF-A. Check your cellular protective antioxidant barrier such as SOD2.
What pulled Andy’s trigger?
Andy’s lifestyle included a stressful business that required him to travel frequently across the Atlantic. This gave him two strong triggers – stress and aeroplane pollution. He also had an episode of food poisoning four years previously, which was treated with a long course of antibiotics (which can damage the gut microbiome). This continued to give him minor short-lived recurrent episodes of diarrhoea.
Going back to early childhood, Andy admitted to eating too many sweets, which damaged his teeth, later resulting in multiple dental fillings and bleeding gums. This may have added a small element of periodontal disease.
Having a recurrent infection, a long course of antibiotics, environmental toxins and possibly periodontal disease may have generated the perfect storm of factors, which triggered the low-grade inflammation and oxidative stress necessary for the build-up of cholesterol plaques and thus vascular disease.
Why are plaques so dangerous?
Plaques build up along the inner wall of the arteries, eventually clogging them. The plaques accumulate from various elements that circulate in the blood, including calcium, cholesterol, cellular debris and waste. As the plaques continue to accumulate, the arteries narrow and harden.
This clogging (atherosclerosis) does not usually cause any symptoms until a major event occurs, such as a heart attack or a stroke caused by a complete blockage. And it normally requires an arterial blockage of 70% or more to trigger cardiac symptoms, including chest pain (angina), shortness of breath, palpitations, or dizziness.
Most patients with heart disease receive the appropriate swift medical treatment. Those with a higher grade of arterial blockage (70% or more) are usually offered a stent; a small tube placed where the artery has narrowed to maintain adequate blood flow. Some may be offered a coronary artery bypass (heart surgery).
How well do you know your family?
You need to identify any member of your family who had had heart disease, along with their age when they were first diagnosed.
If an immediate male family member (a father or brother) had a heart attack, a stroke, or was diagnosed with heart disease before the age of 55, or an immediate female member (mother or sister) before 65, then you have a family history of premature heart disease. And I am sorry to say that this means that your chances of developing the same condition are higher than normal.
If you do have a strong family history of heart disease, then it would be sensible to seek medical advice before the age of 40 – in other words, before you have any symptoms. This is because heart disease symptoms do not manifest themselves until your disease has significantly progressed. Therefore, early medical advice is literally vital.
Aside from seeking early medical advice in this way, if you do have a family history of heart disease, you should stop smoking, reduce your alcohol intake, stay physically active, eat a healthy balanced diet, keep a healthy weight, and body shape, and manage any high blood pressure, high cholesterol, or diabetes.
Please share your thoughts and ask any questions on this subject, and please do subscribe to the newsletter so that you don’t miss further vital information. Thank you!
Genetics of coronary artery disease
A candidate genetic risk factor for vascular disease: a common mutation in methyl tetra hydrofolate.
Know your risk: family history of heart disease
Genetic of cardiovascular disease: how far are we from personalised CVD risk prediction and management?