Heart health, are you at risk?
I'm excited about developments in our understanding of heart disease, how it develops and new toolkits for prevention and early diagnosis. An increasing proportion of people suffering from heart attacks do not have any of the "traditional" risk factors such as high blood pressure or abnormal cholesterol. For some reason these patients are 50% more likely to die in the first 30 days after their heart attack. Researchers are now looking at the involvement of inflammatory pathways, environmental exposures, autoimmune disease, genetics and diet and trying to identify biochemical markers that predict increased risk. Here are some of the "new" biochemical markers that I pay attention to:
Insulin
Insulin resistance develops when certain nutrients are missing, with excess weight and genetic predisposition. Cells struggle to take up glucose from the bloodstream in the presence of high insulin levels which also acts as a cell growth factor and is pro-inflammatory. This results in damage to the lining of the blood vessels causing vascular disease to develop.
Testing for fasting Insulin and comparing it with sugar levels gives us a good idea of baseline insulin sensitivity, also known as the HOMA index. Another way is to look at what happens to insulin and glucose levels following ingestion of a very sweet drink - a ‘glucose challenge’. This is a more challenging test but it gives us very good information about how the body might respond in real-life situations.
Insulin resistance is one of the earliest markers of metabolic disease and can precede the diagnosis of diabetes and cardiovascular disease by a number of years. It can also lead to the development of Polycystic Ovarian Syndrome due to hormonal changes. For a list of nutrients that are helpful for reducing insulin resistance check this great review. Although the article talks mostly about PCOS, most of the nutrients mentioned in it act through the insulin resistance pathway and include magnesium, chromium, b-vitamins, zinc and vitamin D. Best of all, we have a lot of experience in helping patients reverse insulin resistance through lifestyle, diet, exercise and herbal supplements.
High Sensitivity CRP (hs-CRP)
CRP is a protein produced by the liver in response to inflammation. Elevated levels of hs-CRP are associated with inflammatory processes affecting the blood vessels and increased risk of atherosclerosis (plaques in blood vessels). It is particularly interesting that increases in hs-CRP have been noted in patients who had heart attacks and strokes but had no other traditional risk factors.
Homocysteine
Homocysteine is an amino acid and abnormally increased levels of homocysteine correlate very significantly with cardiovascular risk. Elevated homocysteine levels can cause damage to the walls of arteries, promoting the formation of plaques and blood clots. It has been overlooked for a long time with most people not being aware of the fact that it is actually possible to lower homocysteine by supporting the body's methylation cycle. Homocysteine is usually moved on to become methionine. However, deficiencies in Vitamins B2, B3, B6, B12 and folate, zinc and certain genetic variants such as a slow MTHFR enzyme can slow down homocysteine metabolism. Genetic testing can identify gene variants that slow down biochemical reactions required to clear homocysteine. We can use blood tests to check for levels of homocysteine and nutrients that are essential for homocysteine metabolism. Targeted lifestyle, nutritional and nutraceutical interventions can help overcome these metabolic bottlenecks.
LDL particle size
Low-density lipoprotein (LDL) is often referred to as ‘bad cholesterol’ because high LDL levels have been linked to an increased risk of cardiovascular disease. This is now a quite outdated test because there are actually other subfractions of LDL such as VLDL and these can give a much better prediction of actual risk. In fact not everyone with increased total cholesterol level is in a high risk category especially if the pattern of particle size shows a benign pattern.
LDL particles come in a variety of sizes - you can imagine them as tiny balloons. Some of them are larger, smaler, lighter or denser. Research has shown that the pattern and ratio of these different particles can predict risk. If your cholesterol is very high then medicare may pay for analysing these subfractions, otherwise patients have to pay privately.
Coronary Calcium Score
A coronary (heart) calcium score is an amazing test that uses CT imaging to measure the amount of calcification or "hardening" in the coronary arteries. The score is calculated based on the amount of calcium detected in the arteries - higher scores indicate a greater amount of plaque and a higher risk of cardiovascular events. This test is usually recommended for people who are not symptomatic but are considered at a higher risk due to their age, family history, genetics or have some of the traditional cardiovascular risk factors. The results can guide decisions about lifestyle interventions, medications and further testing. There have been some surprises with patients thought to be at high risk initially actually having a calcium score of 0 which puts them in the lowest risk category where the cardiologist then actually stopped their cholesterol lowering meds.
Genetics
Although there is no single gene that determines the risk of cardiovascular disease, we know of a number of gene variants that can contribute to the risk profile. Some of them include:
Lipoprotein-a (LPA)
Low-density lipoprotein receptor (LDL-R)
Apolipoprotein E (APOE)
Endothelial nitric oxide synthase (eNOS)
Some of these genes are linked to the body’s ability to regulate cholesterol while others are important for the health of blood vessel walls and the maintenance of healthy blood pressure. It is important to remember that, in this case, genetics does not determine the outcome - even when genetics is not on your side there is a lot that we can do to prevent cardiovascular disease.
Being female
The way in which the heart and circulatory system age in women is quite different from what happens in men. Hormone fluctuations have a significant effect, menopause and dropping estrogen levels affect the structure of coronary arteries and heart attacks in women often do not present with classic symptoms we see in men. In fact, women are 50% more likely to be misdiagnosed following a heart attack.
Migraines, hypertension in pregnancy, early menopause and inflammatory and rheumatological conditions are additional risk factors for heart disease in women. There are many things we can do to make sure that women get assessments and treatments better suited to them. ‘A Woman’s Heart’ by Dr Angela Maas is a fascinating book that deep dives into this topic.