Did you know DNA affects your cardiovascular health?
Healthy hearts - genetic clues to reducing the risk of a heart attack
“Is there a family history of heart disease?” A simple question present in every intake form, whether it is at the walk-in clinic, the hospital, or at your new doctor’s office. You may think the question is odd or out of place. However, family history provides doctors with important information – a clue about your cardiovascular health based on your genes.
Cardiovascular disease is an all-encompassing term that includes all conditions affecting the heart and blood vessels, such as coronary artery disease, angina, heart attack, stroke, and arrhythmia. Cardiovascular disease is the number one cause of death in the US, claiming over 600,000 lives each year. We all know that poor lifestyle choices, (e.g. physical inactivity, unhealthy eating habits, excess alcohol and smoking), increase the risk of heart problems. But there are some of us that also inherit certain genetic variants that increase the risk of a heart attack.
These genetic factors affect the storage, metabolism and transport of lipids (fats), predisposing susceptible individuals to poor cardiovascular health. The predominant fats – triglycerides and cholesterol – are the main culprits behind the risk of cardiovascular disease. Triglycerides (storage lipids) are an essential part of our diet, as they act as a source of energy between meals. However, high levels are associated with poor cardiovascular health. Cholesterol is another type of lipid, which is an essential structural component in all of our cells, and an important molecule for the biosynthesis of steroid hormones.
The link between cholesterol and heart health, is based on how cholesterol is transported, which is via lipoproteins. Two lipoproteins are the most relevant to cardiovascular disease – low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs). LDLs transport cholesterol in the blood and can build up in the walls of blood vessels blocking them. HDLs are the “good” lipoproteins, as they remove cholesterol from cells, taking it to the liver to be excreted. Low “good” HDL-cholesterol levels, or elevated levels of “bad” LDL-cholesterol and triglycerides, increase the chance of a heart attack. In fact, the ratio between triglyceride levels and HDL-cholesterol is one of the best predictors of cardiovascular disease risk.
It is not surprising then that many of the genetic changes linked to cardiac health affect the levels of triglycerides and cholesterol. For example, changes in the lipoprotein lipase (LPL) enzyme reduce the efficiency of triglyceride breakdown, leading to the buildup of these fats in the bloodstream. Similarly, the MMAB (mitochondrial enzyme cob (I) alamin adenosyltransferase) protein normally breaks down cholesterol, but people with variants that produce too much of this protein have lower HDL-cholesterol levels and are at higher risk for cardiovascular disease. In contrast, variants of the CETP (cholesteryl ester transfer) protein can elevate HDL-cholesterol levels and offer protection from heart disease. These are only a few examples of the many genetic changes linking triglycerides and cholesterol to cardiovascular health.
While you have no control over the genes that you inherit, or the genetic risk for disease that is passed on to you, all hope is not lost. Studies show that healthy habits can drastically reduce or even eliminate the genetic risks of heart disease. Thankfully, from activity trackers to calorie counters, we live in an era where the means necessary for healthy living is at our fingertips. Maintaining the health of your heart has never been easier. All that is left is to find out your risk, so you can act to tamp it down.