Healio
Healio
August 13, 2010
6 min read
Save

Viewpoint: Cardiovascular risk management in type 2 diabetes, screening and education

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Endocrine Today interviews Kathleen M. Dungan, MD, Assistant Professor of Medicine, Division of Endocrinology, Diabetes, & Metabolism, at Ohio State University in Columbus, Ohio. Part 2 of a 2-part series. Read Part 1 of the interview with Dr. Dungan here.

When trying to reduce the risk for cardiovascular events in your patients, do you take a different approach to diet in a patient with type 2 diabetes than in a patient with cardiovascular disease?

For both CVD and type 2 diabetes, the main focus of a particular diet should be caloric restriction for the purposes of weight loss, not the macronutrient composition of the diet per se. Adjusting the macronutrient composition has not been shown to be superior to caloric restriction alone in terms of sustained weight loss. Individual palatability may be important for a person to achieve sustained weight loss. However, patients could benefit from macronutrient restriction for reasons other than weight loss. Patients with diabetes may require some limitations on carbohydrate intake in order to preserve effective glycemic control, but this can be individualized. Likewise, patients with CVD are at increased risk for impaired fasting or postload glucose, and such patients may also benefit from carbohydrate limitation. Unfortunately, focused efforts to lower postprandial glucose have not consistently been shown to improve CV outcomes.

Second, patients with significant hyperlipidemia may find it difficult to follow a low-carbohydrate diet because the macronutrient composition of the low-carbohydrate foods may be high in cholesterol. Furthermore, low-carbohydrate diets tend to be high in protein, which is not desirable in patients with advanced renal disease. Patients should individualize their diets within the constraints of their caloric requirement. Recommendations for patients with type 2 diabetes who have dyslipidemia include:

Kathleen M. Dungan, MD
Kathleen M. Dungan
  • Reduce saturated and trans-fats. Trans-fats are doubly dangerous; they raise LDL cholesterol and lower HDL cholesterol.
  • Increase the intake of monounsaturated fats and omega-3 fatty acids. These fats may have important cardioprotective effects. Monounsaturated fats are found in certain nuts and olive oil, and omega-3 fatty acids are found in fatty fishes such as salmon. All fats still contain calories, so the general approach should be to substitute good fats for bad (saturated and trans) fats.
  • Increase viscous fiber and fiber intake in general. Good sources of fiber include whole grain breads and cereals and many fruits and vegetables. Among other benefits, fiber tends to lower cholesterol and limit postprandial glucose excursions.
  • Increase the consumption of fruits and vegetables for their macronutrient and micronutrient benefits. These foods are generally less calorie dense, and contain important micronutrients and fiber. A wide variety of (preferably fresh) fruits and vegetables is advised.
  • Reduce intake of sodium and optimize potassium intake (the latter determined on an individual basis) in patients with hypertension. This is particularly important for management of patients with hypertension, renal disease, or heart failure. Patients should be instructed to pay attention to processed foods such as canned soups and frozen prepared meals, which may contain high amounts of “hidden” sodium.

How can physicians educate their patients about the relationship between type 2 diabetes and CVD?

Physicians should encourage their patients to take a global view of their health and not just focus on their glucose. Often, patients forget about their blood pressure and their weight. Emphasizing “bigger picture” thinking can be helpful to physicians and patients, especially when many patients take multiple medications, not only to regulate blood glucose but also to control blood pressure, lipid levels and other health problems.

When patients participate in a comprehensive weight loss program (rather than simply dieting), they experience more long-term success. All patients are different, and comprehensive weight loss management programs take into account factors that may prevent patients from losing weight, including psychological barriers, eating disorders, and exercise limitations.

What are the differences in care regarding CV risk management in patients with and without type 2 diabetes?

The main difference is that patients who do not have type 2 diabetes currently have lower blood pressure goals and lipid goals than patients with type 2 diabetes. The current blood pressure target reported by the American Diabetes Association (ADA) and the Seventh Report of the Joint National Committee on Prevalence, Detection, Evaluation, and Treatment of High Blood Pressure is less than 130/80 mm Hg and is based largely upon epidemiologic evidence. The recent ACCORD blood pressure study results did not demonstrate superiority of very tight (systolic pressure <120 mm Hg) blood pressure control compared with standard therapy (target systolic pressure <140 mm Hg). However, it is unclear whether the current guidelines will change based upon this study.

Current lipid targets were established through the Adult Treatment Program III guidelines of the National Cholesterol Education Program (NCEP) and the ADA. People who do not have diabetes, the primary lipid target is LDL cholesterol, individualized according to CV risk. People with known CVD or CV risk equivalent generally have a target LDL of less than 100 mg/dL. Patients with diabetes have similar treatment goals as those with CVD because they have very high risk. According to the ADA, an option is to lower the target to less than 70 mg/dL in those at very high risk (eg, those with diabetes and CVD). As an alternative, the ADA suggests that an LDL reduction of 30% to 40% may be more appropriate for some individuals (eg, those with difficulty reaching the target or those who are minimally above target at baseline).

An ADA-American College of Cardiology consensus panel also recognizes the potential utility for apolipoprotein B measurement, which more comprehensively measures all atherogenic lipoprotein particles (target Apo B <80 mg/dL if the LDL target is <70 mg/dL and <90 mg/dL if the LDL target is <100 mg/dL). Non-HDL target of 30 mg/dL higher than the patient’s LDL target may be an appropriate secondary target for those patients with modest triglyceride elevation (200-499 mg/dL). Other secondary targets include HDL (>40 mg/dL in men and >50 mg/dL in women) and triglyceride (<150 mg/dL). In the presence of severe hypertriglyceridemia (>500 mg/dL), however, triglycerides become the primary target in order to prevent pancreatitis. Currently, the guidelines do not offer specific recommendations on the use of detailed lipoprotein panels, but additional updates from the NCEP are expected in 2011. The ADA recognizes the complexity of dyslipidemia in patients with diabetes, in which CV risk is not adequately captured by LDL alone. As a result, the ADA recommends statin therapy in any patient with type 2 diabetes older than age 40 years who has additional CV risk factors, regardless of LDL level. There is limited evidence for patients with type 1 diabetes and for patients younger than 40 years of age for nontargeted statin therapy.

Among patients with type 2 diabetes, which subpopulations have increased risks for CVD? How can physicians specifically target these populations in their care methods?

All patients with diabetes are generally considered to be in that "CV risk equivalent" category (see Part 1 of this interview), but even within that category, some patients are at heightened risk. Although some recent data are conflicting, patients with type 2 diabetes who do not have CVD are generally regarded as having about the same risk for a CV event as patients with known CVD who do not have diabetes. This increase in risk begins well before a patient is ever diagnosed with diabetes, since prediabetes itself is associated with CVD. Among patients with CVD, those with diabetes have an even higher risk for a subsequent CV event than those who do not have diabetes. Other risk factors include age, hypertension, dyslipidemia, family history and a history of smoking.

Another factor that is not widely recognized is microalbuminuria. Patients who have diabetic nephropathy have a greater CV risk than patients who do not have nephropathy, possibly due to similarities in pathophysiology.

The most important factor in preventing CV events is early management. Physicians should specifically target these at-risk populations by screening early for diabetes and components of the metabolic syndrome. By the time diabetes is diagnosed, it may be too late to prevent CVD associated with type 2 diabetes. Appropriate and early screening procedures can ensure that associated risks are more aggressively managed.

Should all populations be screened for type 2 diabetes?

According to the ADA, screening should begin at age 45 years or younger in patients who are overweight with additional risk factors. The risk factors for diabetes include age, weight (ie, obesity), physical inactivity, hypertension, low HDL, high triglyceride level, hypertension, polycystic ovarian syndrome, history of impaired fasting or postload glucose or HbA1c greater than 5.7%, CVD, history of gestational diabetes and specific ethnicities (eg, African Americans and Native Americans have nearly a 50% projected lifetime incidence of developing type 2 diabetes). However, the U.S. Preventive Services Task Force only recommended screening asymptomatic adults with blood pressure >135/80 mm Hg and otherwise stated that the current evidence is insufficient to assess the balance of benefits and harms of routine screening. The Centers for Disease Control and Prevention recently released a statement that discouraged nontargeted screening but indicated that “periodic screening of high-risk individuals as part of ongoing medical care may be warranted, understanding that evidence in support of this is incomplete. Clearly, more research needs to be done.

Screening should take place at least every 3 years, and patients who have prediabetes or exhibit several risk factors should consider annual screening. This is something most physicians know, but it is important that they ensure that their patients are aware. Most endocrinologists do not see these patients until they are either admitted to the hospital or they are on insulin therapy and have had diabetes for years. Therefore, education in the primary care realm is imperative.

Is it appropriate to routinely screen for diabetes in adolescents?

According to the ADA, adolescents should be screened beginning at age 10 or earlier in case of earlier puberty if they are overweight and have additional risk factors. Because increased weight and other risk factors are so common, many patients will need to be screened on a fairly regular basis, even in their teens.

For more information:

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.