Your Heart Health: What Family History Tells You
It’s good that you are actively thinking about what steps you can take to prevent history from repeating itself. Although cardiovascular disease (CVD)—the number one killer and a leading cause of premature, permanent disability in the US—may be more common in families with a positive family history of CVD, the outlook is far from hopeless.
Scientists have established that several risk factors—both modifiable (such as diet, physical activity level, and tobacco use) and nonmodifiable (like age and genetics)—play a role in the development of CVD. Moreover, scientists aren’t even sure if the increased risk of developing CVD in someone with a family history of the disease is solely a result of a shared genetic predisposition or if it simply represents a greater exposure to the same harmful environmental influences.
Genetics and Cardiovascular Risk
The Human Genome Project (the scientific undertaking to identify all the genes in human DNA) has sparked enthusiasm for the possibility that doctors might assess specific genes to determine individual disease risk. Examples of genetic influences on cardiovascular risk currently under study include the following:
- Genes that appear to predispose a person to congenital heart disease (heart disease from birth)
- Apolipoproteins B and E (proteins that combine with a lipid that affect blood cholesterol concentrations)
- The angiotensinogen gene variant (an alteration in the hormone angiotensinogen, which is associated with high blood pressure )
- Homocysteine (an amino acid which contributes to atherosclerosis by irritating vascular endothelial cells lining the blood vessels)
- C-reactive protein (a protein that is a marker of inflammation and may predict future cardiovascular risk)
However, while genetic and protein markers may identify enhanced CVD risk (and would allow for targeted prevention) further confirmation is required before widespread clinical use is indicated.
What is known is that CVD occurs more commonly in families with a positive family history of the condition. This means that your risk of CVD is increased if any of your immediate relatives, such as siblings, parents, or children, have or had heart disease, a heart attack , or stroke , especially before age 50. In general, a positive family history is associated with an increase in risk of 2-5 times that of the general population.
How Knowing Your Family History Can Help
Research clearly demonstrates that family history of CVD is an independent predictor of disease. One recent study looking at CVD in families in Utah found that while only 14% of families had a strong positive family history of coronary heart disease (CHD), these same people accounted for 72% of all CHD events (such as heart attack and coronary bypass surgery ).
And, while only 11% of families had a positive family history of stroke, 86% of all early strokes occurred in these families. Since major cardiovascular risks (such as smoking and excessive alcohol consumption ) may be less prevalent in Utah than in other states, these results may not apply throughout the country.
Nonetheless, because family members share not just the same positive family history, but also other modifiable risk factors as well, family history can help doctors capture the underlying complexities of both genetic and environmental (behavioral) influences leading to the appearance of disease.
Perhaps most important, people at risk for CVD because of their genetic makeup can benefit from modifying their behavior. For instance, quitting smoking is projected to decrease CHD to a greater extent in men with a positive family history of CHD compared to men without a positive family history.
And, reducing cholesterol could prevent 44% of all five-year CHD deaths in men and 57% in women in families with a history of hypercholesterolemia (an inherited genetic condition that results in markedly elevated levels of LDL-cholesterol beginning at birth).
Family history is thus an important tool used by doctors to evaluate risk of CVD. In fact, the latest American Heart Association (AHA) guidelines for the prevention of coronary heart disease and stroke recommend that doctors regularly update patients’ family histories.
What to Do If You Think You Might Be at Risk
In the future, as the genetic basis of CVD is unraveled, doctors may be able to diagnose disease based on tests for genetic markers.
In the meantime, while a family history of CVD doesn’t doom you to the same fate, you are at a higher risk. Therefore, modifying certain risk factors for CVD, may help you reduce your risk of disease. These modifiable risk factors include the following:
- Quitting smoking
- Reducing the total fat, trans fat, and saturated fat in your diet
- Increasing fiber in your diet
- Controlling your blood pressure
- Controlling your diabetes
- Exercising regularly
- Maintaining an ideal body weight
- Managing your stress
- Moderating your alcohol intake
- Lowering your total cholesterol, triglycerides, HDL, and LDL levels
Remember, prevention is key. Keep in mind, too, that if you have a family history of CVD, your children are at an increased risk as well. But you can set them on the right path to a healthful lifestyle. Children learn from example. So, if they see you eating right, not smoking, and getting plenty of exercise, they’ll be more likely to follow your lead.
RESOURCES:
American Heart Association
http://www.americanheart.org/
Men’s Health Network
http://www.menshealthnetwork.org/
National Heart, Lung, and Blood Institute
http://www.nhlbi.nih.gov/
CANADIAN RESOURCES:
Canadian Association of Family Physicians
http://www.cfpc.ca/
Canadian Public Health
Health Unit
http://www.phac-aspc.gc.ca/pau-uap/fitness/
References:
Day INM, Wilson DI. Genetics and cardiovascular risk. BMJ. 2001;3232:1409-1412.
Hunt SC, Gwinn M, Adams TD. Family history assessment: strategies for prevention of cardiovascular disease. Am J Prev Med. 2003;24:136-142.
Jomini V, Oppliger-Pasquali S, Wietlisbach V, et al. Contribution of major cardiovascular risk factors to familial premature coronary artery disease: the GENECARD project. J Am Coll Cardiol. 2002;40:676-684.
Khot UN, Khot MB, Bajzer CT, et al. Prevalence of conventional risk factors in patients with coronary heart disease. JAMA. 2003;290:898-904.
Men and cardiovascular diseases. American Heart Association (AHA) website. Available at: http://www.americanheart.org/downloadable/heart . Accessed August 25, 2003.
Olden K, Wilson S. Environmental health and genomics: visions and implications. Nature Reviews: Genetics. 2000;1:149-153.
Pearson, TA, Blair SN, Daniels, SR, et al. AHA guidelines for primary prevention of cardiovascular disease and stroke: 2002 update. Circulation. 2002;106:388.
Preventing heart disease and stroke: addressing the nation’s leading killers. Centers for Disease Control and Prevention (CDC) website. Available at: http://www.cdc.gov/nccdphp/publications/factsheets/Prevention/dhdsp.htm . Accessed April 28, 2009
Women and cardiovascular diseases. American Heart Association (AHA) website. Available at: http://www.americanheart.org/downloadable/heart . Accessed August 25, 2003.
Yoon PW, Scheuner MT, Peterson-Oehlke KL, et al. Can family history be used as a tool for public health and preventive medicine? Genetics in Medicine. 2002;4:304-310.
Last reviewed April 2009 by Marcin Chwistek, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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