WASHINGTON, DC — Cardiologists and other healthcare professionals have waited years for the updated National Heart, Lung, and Blood Institute (NHLBI)–sponsored guidelines on cholesterol, blood pressure, and obesity management in adults. Today, with the release of (most of) these updates—albeit in a new form—come two new guidance documents, one on assessing CV risk and another tackling one of the most fundamental but frequently overlooked issues: lifestyle.
The 2013 AHA/ACC Guideline on Lifestyle Management to Reduce Cardiovascular Risk, chaired by Dr Robert Eckel (University of Colorado, Anschutz Medical Campus) and Dr John Jakicic (University of Pittsburgh, PA), is published alongside three other sets of ACC/AHA coordinated guidelines in both the Journal of the American College of Cardiology and Circulation. The lifestyle guidelines, as with the other guidelines, are accompanied by a companion document representing the "NHLBI Systematic Review."
Speaking with reporters, Eckel explained that the aim of the lifestyle guidelines was to "reevaluate and update the concept of a healthy lifestyle," with the specific aim of preventing progression to cardiovascular disease in at-risk patients.
As such, the recommendations cover evidence related to dietary patterns, nutrient intake, and levels and types of physical activity that play "a major role in cardiovascular disease prevention and treatment through effects on modifiable CVD risk factors," namely high LDL cholesterol and hypertension, he said.
The lifestyle guidelines, as with the other NHLBI-sponsored documents, were intended for use by primary-care doctors as well as subspecialists, Eckel emphasized. While the full guidelines run 45 pages in length, there are three major findings:
Eat a dietary pattern that is rich in fruit, vegetables, whole grains, fish, low-fat dairy, lean poultry, nuts, legumes, and nontropical vegetable oils consistent with a Mediterranean or DASH-type diet.
Restrict consumption of saturated fats, trans fats, sweets, sugar-sweetened beverages, and sodium.
Engage in aerobic physical activity of moderate to vigorous intensity lasting 40 minutes per session three to four times per week
Of note, the writing group "did not have the time or resources" to investigate other aspects of lifestyle and diet—namely calcium, magnesium, and alcohol intake; cardiorespiratory fitness; single behavioral intervention or multicomponent lifestyle interventions; the addition of lifestyle intervention to pharmacotherapy; and smoking. These may, however, have "potential benefits," Eckel said.
In tables spelling out the specific guidelines, recommendations are broken out according to whether an adult in question has higher-than-desirable lipid profiles or higher-than-desirable blood-pressure levels, although the recommendations for both groups are very similar.
Low-Fat Diets Give Way to Mediterranean
Of particular note, the guidelines emphasize Mediterranean-style dietary patterns over a "low-fat dietary pattern," which is scarcely mentioned in the document, although "low-fat dairy products" are part of the dietary pattern advice. There are no specific recommendations to reduce overall fat consumption, only to reduce the percent of calories consumed from saturated and trans fats.
Also notable are the recommendations on sodium. The general recommendation to "reduce sodium intake" is given a level of evidence A (strong), in the NHLBI grading system or a class IA by the ACC/AHA grading system. By contrast, advice to further restrict sodium intake to 1500 mg/day as "desirable" is given level of evidence B (moderate)/class IIa-B.
Dr Alice Lichtenstein (Tufts University, Boston, MA), a coauthor on the guidelines, noted that mean daily sodium intake in the US is about 3.5 g. "We're all consuming too much sodium . . . and it's absolutely critical to reduce it." However, she continued, "accurately assessing sodium intake is extremely difficult and probably clouds the whole issue, as does the [use of a] specific target.
"What we really need to emphasize is that most of the sodium consumed is consumed as processed foods, so just focusing on a salt shaker on the table is not going to result in the reductions we want to see. Therefore, we really need a concerted effort and a partnership with public-advocacy organizations like the ACC and [the AHA] and the food industry to reduce sodium content in general across the board."
Eckel, also responding to heartwire 's question about sodium targets, said that the working group did review evidence looking at specific sodium targets, "and there is evidence that people who cut back a gram a day do have lower blood pressures."
Keep in mind, he continued, that these lifestyle recommendations are intended for people already identified as having a problem, and in the case of sodium recommendations, that means people with 'prehypertension" or hypertension. "If the question is, does the [sodium intake] level make a difference? Yes, absolutely. . . . Sodium reduction is an important element of successful blood-pressure lowering. What level should be achieved? I think as low as possible is beneficial, but targeted levels are supported moderately by the evidence that exists and should not be the initial message that we give to our patients at risk."
This will be the last time the guidelines per se will be called "NHLBI" guidelines. The NHLBI announced in June 2013 that it was getting out of the guideline-writing business, choosing instead to focus on the "evidence review and synthesis."
Asked why the NHLBI guideline planners originally took the step of adding a "lifestyle document," Eckel, who led the Lifestyle Working Group for the past five years, told heartwire : "We felt from the very beginning that lifestyle could stand alone in addition to being a component of the updated guidelines for cholesterol and BP. Thus, what we've accomplished is in [the] cholesterol [guidelines] and I presume will remain in [the blood-pressure guidelines] once they appear."
Eckel reports consulting for Foodminds; Jakicic reports consulting for Alere Wellbeing, Jenny Craig, and Nestle Nutrition; and Lichtenstein reports no conflicts of interest. Disclosures for the coauthors are listed in the paper.
Heartwire from Medscape © 2013
Cite this: Shelley Wood. New ACC/AHA/NHLBI Guidance on Lifestyle for CVD Prevention - Medscape - Nov 12, 2013.