麻豆传媒

Obese and overweight adults with at least one other cardiovascular risk factor should receive intensive behavioral counseling to promote healthy diet and physical activity for heart disease prevention, according to a U.S. Preventive Services Task Force (USPSTF) preliminary recommendation.

The draft of the grade B recommendation expands on previous guidance from the task force by including a physical activity component and calling for more at-risk adults to receive behavioral interventions.

This draft will be available for public comment on the until June 9.

"Medium- and high-intensity diet and physical activity behavioral counseling in persons with risk factors for [cardiovascular disease] resulted in consistent improvements across a variety of important cardiovascular intermediate health outcomes up to 2 years," the USPSTF members concluded. "High-intensity combined lifestyle counseling reduced diabetes incidence in the longer-term."

Past recommendations included behavioral counseling that focused on diet alone for adults with hyperlipidemia or other known risk factors for cardiovascular disease (CVD). The evidence was previously deemed insufficient to recommend for or against behavioral counseling in the primary care setting to promote physical activity.

"The new recommendations build on the new science and focus on overweight or obese people with various cardiovascular risk factors," said task force member , dean of the College of Public Health at the University of Iowa in Iowa City. "And they include a physical activity component as well as a dietary component."

'Small but Important Changes in Behavior'

The task force reviewed 74 trials, including 71 with information on intermediate health outcomes such as cholesterol, blood pressure, body mass index (BMI), and fasting glucose.

The reviewed evidence demonstrated the effectiveness of intensive counseling to "make small but important changes in health behavior outcomes and selected intermediate clinical outcomes" of overweight and obese people with additional risk factors for CVD, measured after 12 to 24 months, according to the task force report. Specifically:

• Total cholesterol decreased by approximately 3 to 6 mg/dL, and LDL decreased by approximately 1.5 to 5 mg/dL.
• Systolic and diastolic blood pressure decreased by 1 to 3 mm Hg and 1 to 2 mg Hg, respectively.
• Reductions in fasting glucose were approximately 1 to 3 mg/dL.
• Diabetes incidence was reduced by up to 42% in trials reporting outcomes after 3 years.
• Weight decreased by an standardized mean difference of 0.26, or about a 0.5 to 1.5 kg/m² BMI reduction, or approximately 3 kg on average.

Based on self-reported physical activity, the proportion of people who participated in moderate intensity exercise for 150 minutes per week increased from 10% to 25% following counseling.

Key Components of Counseling

Curry told 麻豆传媒 that key components of intensive behavioral counseling include instructional education, an individualized action plan, help with problem solving, and feedback.

Behavioral counseling can include both face-to-face meetings and telephone or electronic contact. In addition to physicians, counseling can be performed by health educators, psychologists, nutritionists, dietitians, exercise professionals, and others in the health field.

For the purposes of the USPSTF analysis, low-intensity interventions were 30 minutes or less, medium-intensity interventions were 31 to 360 minutes, and high-intensity interventions involved over 360 contact minutes.

In the trials considered by the USPSTF, approximately two-thirds of the medium-intensity interventions had 120 minutes or more of contact time; the median number of contacts was five and median duration of intervention was 9 months.

Diet-only and physical activity-only counseling interventions were mostly medium-intensity. High-intensity interventions were those having greater than 360 minutes of contact; the median number of contacts was 16 and median duration of intervention was 12 months.

Specially trained individuals delivered these interventions, including dietitians or nutritionists, physiotherapists or exercise professionals, as well as health educators, nurses, or psychologists.

Counseling interventions generally focused on behavioral change and could include co-interventions. Ten trials explicitly reported medication adjustment or counseling around medication adherence as part of the intervention protocol. In one of these 10 trials, the intervention protocol around medication adjustment focused on withdrawal or tapering off of participants' antihypertensive medications.

"Using qualitative analyses and meta-regressions, we did not find that the intervention's format (e.g., face-to-face, group, individual, phone), the person delivering the counseling, the number of sessions, or the duration of intervention significantly affected the direction or magnitude of benefit," the task force noted.

In terms of intervention delivery, the task force cited two "well-researched interventions:" the (DPP) and PREMIER.

The DPP evaluated whether weight loss through a healthy diet and physical activity could prevent or delay onset of type 2 diabetes. The looked at whether counseling to make comprehensive lifestyle changes could prevent or control high blood pressure.

Both "could be delivered feasibly in the primary care setting or by local community providers," the task force members wrote.

Counseling Had Modest Impact on Health

The task force considered 16 trials that reported the effect of the intervention on patient health outcomes (including CVD events, mortality, quality of life, or depression symptoms). Five of these trials reported cardiovascular events including mortality and four of the five demonstrated no reduction in CVD events or CVD mortality at 6 to 79 months.

CVD event rates were low, however. One trial, the Risk Factor Intervention Study (RIS), demonstrated a reduction in a composite measure of CVD events at 6.6 years of follow-up (relative risk 0.62, 95% CI 0.42 to 0.92). The trial combined a healthy diet and physical activity counseling intervention with medications to manage CVD risk factors in Swedish men. The RIS participants had high rates of smoking, diabetes and previous myocardial infarctions as well as a 20% mortality rate during the trial.

Four trials of combined lifestyle interventions did not appear to improve self-reported depressive symptoms in participants with impaired fasting glucose of glucose tolerance at 6 to 12 months. The results on self-reported quality of life measures were mixed. Three combined lifestyle counseling trials and two physical activity-only counseling trials showed no benefit on self-reported quality of life at 6 to 12 months.

Related Recommendations

The USPSTF also recommended screening patients for obesity, and patients with a BMI of 30 kg/m² or greater should be offered or referred to intensive, multi-component behavioral counseling. The task force also recommends that clinicians selectively initiate behavioral counseling to promote healthful diet and physical activity for adults without increased cardiovascular risk.

Other CVD prevention recommendations include screening for lipid disorders in adults depending on their age and risk factors. The USPSTF also suggested screening for blood pressure in adults, screening for diabetes in patients with elevated blood pressure, and aspirin use when appropriate.

Clinicians are also urged to discuss tobacco use with their patients and provide tobacco cessation interventions to those who smoke cigarettes or use other tobacco products.

The latest review did not include interventions specifically focused on weight loss, which were addressed in the USPSTF's 2012 (B recommendation).

The recommends that clinicians provide counseling interventions to promote healthy diet and physical activity, and the (ACSM) has recommendations to assist health professionals who counsel healthy adults on individualized exercise programs.

ACSM recommends 150 minutes of moderate-intensity exercise per week and 2 to 3 days of resistance, flexibility, and neuromotor exercises per week. The (AAFP) is currently updating its recommendations on diet and physical activity.

The task force did caution that "the applicability of these findings depends largely on the availability of intensive counseling in practice and real-world fidelity and adherence to these interventions."

From the American Heart Association:

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