Cardiovascular Disease Risk Associated With Diabetes

Keeping diabetes under control has many benefits, including cutting the risk for cardiovascular events such as coronary artery disease, myocardial infarction, and congestive heart failure.

Cardiovascular disease (CVD) is considered to be the leading cause of morbidity and mortality in the United States. In 2009, an estimated 785,000 Americans had a new coronary attack, and about 470,000 individuals will have a recurrent attack.^1,2 It is estimated that every 25 seconds, an American will have a coronary event, and about 1 individual every minute will die from a coronary event.^1,2

Over the past 25 years, obesity and diabetes have been implicated as 2 of the leading contributing factors to the development of CVD.³ Data from the American Obesity Association indicate that in the United States an estimated 127 million individuals are classified as overweight and 60 million individuals are classified as obese.³ The growing obesity rate has also contributed to the escalating rate of type 2 diabetes cases, especially among the pediatric population. According to the 2010 American Diabetes Association’s (ADA’s) Standards of Care, CVD is considered to be the major cause of morbidity and mortality among individuals with diabetes—and the largest contributing factor to the direct and indirect costs of diabetes.⁴

Examples of circulatory disorders associated with diabetes include coronary heart disease (CHD), stroke, peripheral arterial disease, cardiomyopathy, and congestive heart failure.⁵ According to the American Diabetes Association, the most common conditions coexisting with type 2 diabetes include hypertension and dyslipidemia, both of which are clear risk factors for CVD, and diabetes itself confers independent risk.⁴

Patients with diabetes are at a much greater risk of developing CVD compared with the general population.⁶ They are 2 to 4 times more likely to develop CVD, because chronic hyperglycemia can cause the arteries to narrow and/or lose elasticity.^7-8 Individuals with diabetes also experience twice as many myocardial infarctions compared with the general population. They have lower survival rates after experiencing a cardiovascular event, especially women, who tend to receive less aggressive treatment.^6,9 Among patients with diabetes older than 65 years, an estimated 68% of deaths are due to CHD and 16% are related to strokes.⁹ Some reports reveal that an estimated 80% of individuals with diabetes will die as a result of CVD.¹⁰

When comparing nondiabetic individuals with those with diabetes, women with diabetes, regardless of menopausal status, are 4 to 6 times more likely to develop CVD compared with men, who are 2 to 3 times more likely to develop CVD.⁷ The American Heart Association considers diabetes to be 1 of 6 major controllable risk factors for CVD.⁷ Evidence suggests that although hyperglycemia contributes to myocardial damage after ischemic events, it is clearly not the only contributing factor. Both pre-diabetes and the presence of metabolic syndrome, even in patients with normal glycemic levels, increase the risk of most types of CVD.¹¹

Many factors increase the risk of CVD in the diabetes patient population. These can include dyslipidemia, hypertension, hypercoagulability, poor glycemic control, smoking, obesity, and lack of physical activity, among others.¹⁰

Understanding the Risk for CVD

Results from a 2002 US survey among diabetes patients reported that an estimated 68% of those surveyed did not consider themselves at risk for CVD.¹¹ Furthermore, only 50% of those surveyed reported that their health care providers discussed the high risk of CVD in diabetes and what measures should be implemented to decrease that risk.¹¹ Fortunately, due to increased awareness, health care professionals now focus on measures to decrease the incidence of CVD, especially among patients with diabetes.¹¹

The majority of efforts for reducing or preventing the incidence of CVD, especially among these patients, typically emphasize the importance of lifestyle modifications. These include diet, smoking cessation, incorporation of exercise regimens, lowering blood pressure, controlling low-density lipoprotein cholesterol, and increasing high-density lipoprotein cholesterol level (Table 1).¹²

Many clinicians agree that risk assessment for the primary prevention of CVD and stroke should include regularly updated family medical history, diet plans, smoking and alcohol use history, exercise regimens, body mass index, blood pressure, waist circumference, and the valuation of fasting serum lipoprotein profile and fasting blood glucose levels. ⁶

The 2010 ADA standards of care recommend that all diabetic patients be screened annually for cardiovascular risk factors, which include hypertension, smoking, a positive family history of premature coronary disease, and the presence of micro- or macroalbuminuria. ⁴ Abnormal risk factors should be treated according to the guidelines as well. ⁴ Patients at increased CHD risk should receive aspirin therapy and a statin, as well as an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy if hypertensive, unless there are contraindications to a particular drug class. ⁴ A full summary of the 2010 ADA standards of care can be found at http://care.diabetesjournals.org/ content/33/Supplement_1/ S11.extract.

Findings published in the September 27, 2010 issue of Archives of Internal Medicine report that intensive lifestyle intervention can produce sustained weight loss and improvements in fitness, glycemic control, and CVD risk factors in individuals with type 2 diabetes. ¹³ Incorporation of a regular exercise regimen has been shown to improve blood glucose control, decrease cardiovascular risk factors, contribute to weight loss, and enable patients to live healthier lives. ^4,6,12 Results from various clinical studies have also shown the efficacy of controlling individual cardiovascular risk factors in preventing or slowing the development of CVD among the diabetes patient population (Table 2). ⁴

Increasing awareness and promoting patient education regarding both CVD and diabetes are essential tools to decreasing the incidence of CVD and achieving better glycemic control. A greater understanding of both the risk factors and preventative measures for reducing CVD among the diabetes patient population enables these patients to make informed decisions regarding their overall health. Patients should be encouraged to discuss their cardiovascular risks and treatment options with their primary health care provider. In addition to counseling patients about their medications, pharmacists can assist diabetes patients by encouraging them to adhere to their medication profile, proper diet, and exercise regimen, as well as maintain tight glycemic control and routine visits with their primary health care provider. An excellent patient resource to assess patient risk factors, entitled ADA’s Diabetes PHD, (Personal Health Decisions) can be found on the ADA Web site at: www.diabetes.org/living-with-diabetes/complications/ diabetes-phd/. PT

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

References

1. Heart disease is the number one cause of death. Centers for Disease Control Web site. www.cdc.gov/features/heartmonth/. Accessed October 8, 2010.

2. Lloyd-Jones D, Adams R, Carnethon M, et al. Heart disease and stroke statistics — 2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2009;119:e21-e181.

3. Smith SC. Multiple risk factors for cardiovascular disease and diabetes mellitus. Am J Med. 2007;120(3 suppl 1):S3-S11.

4. Executive summary: standards of medical care in diabetes — 2010.Diabetes Care. 2010; 33(suppl 1):S4-S10.

5. Buse JB, Ginsberg HN, Bakris GL, et al; American Heart Association; American Diabetes Association.Primary prevention of cardiovascular diseases in people with diabetes mellitus: a scientific statement from the American Heart Association and the American Diabetes Association. Circulation. 2007;115(1):114-126.

6. Pereira R, Franz M. Prevention and treatment of cardiovascular disease in people with diabetes through lifestyle modification: current evidence-based recommendations. Diabetes Spectrum. 2008;21:189-193.

7. Cardiovascular disease and diabetes. American Heart Association Web site. www.americanheart.org/presenter.jhtml?identifier=3044762. Accessed October 12, 2010.

8. Cardiovascular complications. Diabetes Life Web site. www.dlife.com/diabetes/information//complications/heart/cardiovascular-diabetes.html. Accessed October 10, 2010.

9. Pignone M, Alberts MJ, Colwell JA, et al; American Diabetes Association; American Heart Association; American College of Cardiology Foundation. Aspirin for primary prevention of cardiovascular events in people with diabetes. J Am Coll Cardiol. 2010;55(25):2878-2886.

10. Triplitt C, Alvarez C. Best practices for lowering the risk of cardiovascular disease in diabetes. Diabetes Spectrum. 2008;21(3):177-189.

11. Dokken B. The pathophysiology of cardiovascular disease and diabetes: beyond blood pressure and lipids. Diabetes Spectrum.2008;21(3):160-165. http://spectrum.diabetesjournals.org/content/21/3/160.full.pdf html. Accessed October 9, 2010.

12. Boucher J, Hurrell D. Cardiovascular disease and diabetes. Diabetes Spectrum.2008;21(33):154-155.

13. Deedwania PC. Long-term effects of a lifestyle intervention on weight and cardiovascular risk factors in individuals with type 2 diabetes mellitus. Arch Intern Med. 2010;170(17):1575-1577.

14. The link between diabetes and cardiovascular disease. National Diabetes Education Program Web site. http://ndep.nih.gov//media/CVD_FactSheet.pdf. Accessed October 12, 2010.

15. Nathan DM, Cleary PA, Backlund JY, et al. Intensive diabetes treatment and cardiovascular disease in patients with type 1 diabetes. N Engl J Med. 2005%u037E353(25):2643-2653.

16. National Institute of Diabetes and Digestive and Kidney Diseases. National Diabetes Statistics Fact Sheet: General Information and National Estimates on Diabetes in the United States, 2005.Bethesda, MD: US Department of Health and Human Services, National Institutes of Health%u037E 2005.