Health Letter, May 2021
By Azza AbuDagga, M.H.A., Ph.D.
Cardiovascular disease (affecting the heart or blood vessels) is the leading cause of death in the U.S. Each year, it kills more than 800,000 Americans and costs over $300 billion in direct health care costs and lost productivity from premature death.
Unhealthy diet and lack of physical activity, high blood pressure or hypertension, diabetes, elevated lipid levels, smoking, and being overweight or obese are well-known modifiable risk factors for cardiovascular disease.
Recently, the U.S. Preventive Services Task Force (USPSTF) — a volunteer panel of national experts in disease prevention and evidence-based medicine that works independently of the drug and medical device industry — examined the research evidence and issued a statement that recommends the routine provision of intensive behavioral counseling aiming to promote a healthy diet and physical activity to adults who have certain cardiovascular risk factors.
Target population and definitions
In the new recommendation, the USPSTF focused on adults aged 18 or older at increased risk of cardiovascular disease, defined as those with at least one of the following risk factors: hypertension or high blood pressure, elevated lipid levels, or mixed or multiple risk factors. The last category was defined as having metabolic syndrome (high blood pressure, high blood sugar, large waistline and abnormal lipid levels) or having an estimated ten-year cardiovascular risk of 7.5% or higher (as determined by a risk tool, such as the Framingham Risk Score or the Pooled Cohort Equations).
The recommendation did not include adults with diabetes or impaired glucose tolerance, who will be covered in a separate future recommendation.
The USPSTF defined a healthy diet as a balance and variety of foods and beverages that assist an individual in preventing disease, achieving and maintaining a healthy weight or supporting health. This includes increasing consumption of healthy foods (such as fruits, vegetables, whole grains, fat free or low-fat dairy and lean proteins) and decreasing consumption of unhealthy foods (such as those with high sodium levels, saturated or trans fats [hydrogenated vegetable oils] and added sugars).
The USPSTF defined physical activity as bodily activity that enhances or maintains physical fitness and overall health. This includes at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic physical activity (including brisk walking, swimming and running) each week as well as engaging in strengthening activities (including climbing stairs, heavy gardening, push-ups or working with resistance bands) at least twice each week.
The USPSTF commissioned a systematic review of randomized clinical trials that focused on behavioral counseling interventions for promoting a healthy diet and physical activity (with or without a focus on weight loss) in adults at increased risk of cardiovascular disease as defined in the previous section.
The researchers of the systematic review identified 94 trials (which enrolled more than 52,170 subjects collectively) that met the USPSTF criteria.
Of all groups in these trials, 67.5% received counseling interventions that included both healthy diet and physical activity counseling interventions, 27.5% received diet-only counseling and the remaining 5% received physical-activity-only counseling interventions.
The behavioral counseling interventions in these trials usually were intensive, involving a median of 12 contacts (individual or group sessions), of which about six contact hours occurred over six to 18 months. Typically, the counseling sessions involved some one-on-one time with the interventionists, who were nonphysicians (including nurses, registered dietitians, nutritionists, exercise specialists, physical therapists, trained counselors and lifestyle coaches). In addition to providing technical information, these counseling sessions included motivational interviewing and behavioral change techniques, such as goal-setting; self-monitoring; and addressing barriers related to diet, physical activity or weight change.
Importantly, when the researchers pooled data from twelve trials that reported cardiovascular disease events (such as heart attack, stroke or peripheral artery disease), they found a 20% lower risk of these events among subjects who received behavioral counseling interventions compared with those who did not receive these services.
The researchers also found that the intervention groups in 91 trials had small improvements in intermediate health outcomes (including blood pressure, lipid levels, body mass index, weight and waist circumference, and composite cardiovascular risk score) after 12 to 24 months of follow-up.
Of all trials included in the review, only 20 included safety data. Eight of these trials reported no adverse effects for behavioral counseling. Most adverse effects in the remaining trials were minor. Notably, trials focusing on physical activity interventions showed that a few subjects reported minor musculoskeletal injuries and that serious adverse events were rare.
Given the results of the systematic review, the USPSTF concluded with moderate certainty that intensive counseling interventions aimed at promoting a healthy diet and physical activity have a moderate net benefit in adults with an increased risk of cardiovascular disease.
Therefore, it recommended that health care professionals assess their adult patients for increased cardiovascular disease risk. For those with increased risk, the USPSTF recommended that primary health care professionals provide such patients with behavioral counseling for healthy diet and physical activity, refer them to receive this type of counseling in other settings or inform them about media-based information about a healthy diet and physical activity.
Examples of relevant media-based information include the 2020-2025 dietary guidelines for Americans, which were developed by the U.S. Department of Agriculture and U.S. Department of Health and Human Services (HHS), and the 2018 physical activity guidelines for Americans, which were developed by HHS.
If implemented widely, the new USPSTF recommendation has the potential to reduce the risk of cardiovascular disease events among many adults with increased cardiovascular risk factors, who comprise a large segment of Americans.
It also is important for this population to work closely with their health care professionals to monitor and control as necessary their other modifiable cardiovascular risk factors, such as high blood pressure and high cholesterol.