Published in UAB Insight, Fall 2006
Lifestyle Interventions Can Reduce Hypertension
ABSTRACT: A national study confirms that people with hypertension can substantially reduce blood pressure with multiple lifestyle changes.
CME OBJECTIVE: The reader will understand how to encourage people to incorporate selective lifestyle changes that can affect blood pressure and other cardiovascular risk factors.
Jamy D. Ard, MD, no conflicts of interest
Although millions remain undiagnosed, more than 30% of the US population suffers from hypertension, defined as blood pressure >140/90 mm Hg. Medical management can control hypertension, yet the American Heart Association reports two thirds of Americans fail to take any or all of their prescribed medicines, including those for blood pressure control.
“Combining targeted behavioral interventions can dramatically improve blood pressure control, reduce risk for chronic disease, and delay or eliminate the need for antihypertensive medications,” says UAB nutrition scientist Jamy D. Ard, MD, who worked with a team of researchers on the 18-month follow-up to the Lifestyle Interventions for Blood Pressure Control (PREMIER) study, funded by the National Heart, Lung, and Blood Institute (NHLBI).
PREMIER determined the blood pressure-lowering effects of 2 lifestyle intervention programs compared with advice alone. Investigators randomized 810 men and women who were generally healthy but had higher-than-optimal blood pressure to 1 of 3 groups. Participants received either advice only; comprehensive lifestyle intervention, including an intensive behavioral program to reduce salt and alcohol intake, increase physical activity, and encourage weight control or weight loss; or comprehensive lifestyle intervention plus the Dietary Approaches to Stop Hypertension (DASH) eating plan.
Previous studies revealed DASH promotes blood pressure reduction to a level similar to treatment with antihypertensive medication. When participants combined DASH with reduced sodium intake, beneficial effects on blood pressure emerged as early as 4 weeks and extended to all individuals in the study, regardless of age, gender, or ethnicity (Ann Inter Med. 2001;135:1019-1028). Combining DASH with reduced sodium intake may be particularly important for sodium-sensitive groups, including African Americans and seniors, Ard adds.
PREMIER researchers found patients could comply with multiple lifestyle modifications, and all 3 groups showed a reduction in hypertension. Reduction was greater, however, in the intervention groups and most significant in the intervention-plus-DASH cohort. At study entry, 37% of participants had elevated blood pressure. At 6 months, hypertension rates in the advice-only group dropped about 5%, but fell 22% in the intervention group that included the DASH diet.
Ard and others investigated if continued monitoring and counseling could extend combined lifestyle and health improvements seen in PREMIER beyond the initial 6 months. Those in intervention groups (who attended 18 counseling sessions in the first 6 months) participated in monthly group sessions supplemented with 3 individual counseling sessions. They kept food diaries, monitored dietary calorie and sodium intakes, and recorded minutes of physical activity. Self-monitoring and group sessions provided feedback, reinforcement, problem solving, and support. More than 60% of PREMIER participants in intervention groups who had elevated blood pressure at study entry had successfully controlled their blood pressure at 18 months.
“Patients who continued with behavioral counseling, increased physical activity, and the DASH diet maintained their reductions in mean blood pressure over 18 months. This study shows people at risk for hypertension and cardiovascular disease can make multiple lifestyle changes to accrue substantial benefit,” he says. “We now have evidence that lifestyle changes can effectively control blood pressure and reduce heart disease risk. With rising insurance costs, Americans are constantly asked to pay more for health care and prescriptions. There is a significant financial incentive for patients to take small steps that may eliminate some of the medicines they take to control blood pressure.”
Maintaining Weight
As director of UAB’s Risk Reduction Clinic, which provides evidence-based care for people with diseases affected by weight and nutrition, Ard is well-versed in the difficulties faced by patients struggling with their weight.
“The DASH eating plan offers a wide variety of foods and can be easily adapted to fit taste preferences,” Ard emphasizes. “It improves cholesterol profiles, lowers diabetes risk, and, as the PREMIER study shows, substantially benefits blood pressure. DASH focuses on high-fiber foods, including fruits and vegetables, and low-fat dairy products. When many patients are first evaluated at the Risk Reduction Clinic, they report eating very little, yet fail to lose weight. While a majority may eat smaller-than-average meals, they are choosing high-calorie items with low nutritional content.”
He advises physicians whose patients attempt lifestyle changes to offer consistent support, but also request accountability. “Ask patients to record everything they eat and every physical activity they perform, and take a moment at their follow-up visit to review the log. Encouraging people to self-monitor is the first step in making them self-aware.”
Patients who are newly diagnosed with hypertension, diabetes, or other conditions that demand lifestyle changes affecting an entire family may benefit from early referral to a nutritionist. However, Ard says, those who have been effectively managed with drugs and want to attempt lifestyle changes to avoid additional medications may benefit more from their primary physician’s continuous support.
Once lifestyle modifications become routine, less intense monitoring is required, but physicians should continue to encourage patients to record activities and focus on overall health more than immediate results, such as weight loss.
“Maintaining weight is as important, and potentially easier to focus on, than losing weight,” Ard says. PREMIER data showed 75% of the 5% to 6% weight loss from baseline to 6 months was preserved at 18 months.
“These modest improvements should be viewed in the context of public health goals that emphasize preventing weight gain and increasing healthy food choices,” he says. “Participants who followed DASH ate more fiber and less saturated fat, reduced sodium intake, and boosted their nutrition. Future data will help further define predictors of success.”
The NHLBI Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) revised clinical guidelines in 2003, emphasizing the benefits of DASH and combining lifestyle changes, but suggesting most patients would require 2 medications to control hypertension. “Maintaining a healthy lifestyle that includes the DASH dietary pattern can have additional benefits on cholesterol and quality of life, even for patients who take multiple medications to achieve adequate blood pressure control. Those who successfully implement lifestyle changes may eventually be able to discontinue one or more drugs,” Ard says.
High Risk for Hypertension
Ard’s next step is focusing on multiple lifestyle modifications to control hypertension in African Americans, who comprised only 34% of the original PREMIER study. He is principal investigator for UAB’s arm of the NHLBI-funded Altering Diet in African American Populations to Treat Hypertension (ADAPT) trial. Other ADAPT collaborators include researchers from Tuskegee University and the Mineral District Medical Society, a group that promotes elimination of health disparities. The 6-month ADAPT study incorporates the DASH plan, but accounts for cultural food preferences. Participants learn to shop for and cook healthy alternatives, such as low-fat sweet potatoes instead of candied yams or smoked turkey in place of pork seasonings, and to incorporate convenience foods into everyday meals. Researchers will measure changes in blood pressure, weight, nutritional intake, insulin, glucose, and lipid levels to identify outcomes.
African Americans are at greater risk for hypertension and related end-stage renal disease. A recent study also found they are 2 to 3 times more likely than whites to have left ventricular hypertrophy, which results from poorly controlled blood pressure and may lead to arrhythmias, ischemic heart disease, congestive heart failure, and sudden cardiac death (Hypertension. 2005;46:124-129).
“This study can help physicians educate patients about changes in diet and physical activity that can help them take control of their blood pressure and health,” says Ard. “We want to make this information available in a format that makes it easy to incorporate these changes into everyday lives.”
Lifestyle Recommendations
| Modification |
Recommendation |
Average Systolic
BP Reduction |
| Weight reduction |
Maintain normal body weight (body mass index 18.5-24.9).
|
5-20 mm Hg/10 kg |
| DASH eating plan |
Adopt a diet rich in fruits, vegetables, and low-fat dairy products with reduced saturated and total fat.
|
8-14 mm Hg |
Dietary sodium
reduction
|
Reduce daily sodium intake to 1.5 g. |
2-8 mm Hg |
| Physical activity |
Regular aerobic physical activity at least 30 minutes a day.
|
4-9 mm Hg |
Moderation of alcohol consumption*
|
Men: limit to ≤2 drinks/day.
Women and lighter weight persons: limit to ≤1 drinks/day.
|
2-4 mm Hg |
| * 1 drink = 12 oz beer, 5 oz wine, 1.5 oz 80-proof whiskey (Modified from NHLBI, JNC 7, 2003) |
For more information
Dr. Jamy Ard
1.800.UAB.MIST
mist@uabmc.edu