Whereas previous scientific statements from the American Heart Association (AHA) have addressed how diet, physical activity, and weight control can help prevent and manage hypertension, a new AHA statement focuses on obesity-related hypertension.
The document, which was published online September 20 in Hypertension, also identifies knowledge gaps and suggests future research directions.
“Given [that] obesity is a major risk factor for hypertension, and hypertension is one of the greatest (if not the greatest) attributable risk factors for most cardiovascular diseases, we thought it was important to focus on weight loss strategies and update what we know about the treatment options that are available to treat obesity hypertension,” writing group chair Michael E. Hall, MD, told Medscape Medical News in an email.
“Medical and surgical strategies may help with long-term weight and blood pressure improvement, in addition to a heart-healthy diet and physical activity,” he noted in a press release from the AHA.
“We often don’t consider medications or metabolic surgery until after there has been target organ damage, such as heart injury or having a stroke.”
However, by acting earlier, “we may be able to prevent these complications,” added Hall, associate division director for cardiovascular diseases at the University of Mississippi Medical Center in Jackson.
“This is not a call for greater use of one specific therapy,” he clarified. “However, we do know that more aggressive treatments including anti-obesity medications or metabolic surgery are underutilized.”
According to Hall, “we treat the secondary problem (ie, the hypertension or diabetes), but we are not treating the root cause [(obesity)] as aggressively.”
“Hopefully this statement will increase awareness that there are several [treatment] options [and] bring attention to this major health issue,” he said.
He added that the most important question, in his mind, is how best to tackle obesity among children and adolescents to lower their risk of hypertension and other associated complications.
The statement is aimed at both primary care providers and specialists.
Diet, Physical Activity Help, but Weight Regain Common
Losing 5% to 10% of body weight can lead to a more than 5-mmHg reduction in systolic blood pressure and a 4-mmHg reduction in diastolic blood pressure, the statement notes. Losing 10 kg may lower systolic blood pressure by 5-20 mmHg.
To manage weight, control hypertension, and reduce the risk of cardiovascular disease, guidelines recommend the Mediterranean diet or the Dietary Approaches to Stop Hypertension (DASH) diet, which both emphasize fruits, vegetables, legumes, nuts, and seeds, with moderate intake of fish, seafood, poultry, and dairy, and low intake of red and processed meats and sweets. The Mediterranean diet also includes olive oil and moderate consumption of (mainly red) wine.
The effect of intermittent fasting on blood pressure control is not clear, the statement notes.
It adds that, typically, 150-225 minutes and 225-420 minutes of physical activity per week can produce weight loss of 2-3 kg or 5-7.5 kg respectively, and 200-300 minutes of physical activity per week is needed to maintain this weight loss.
“Successful weight-loss maintenance over years therefore typically requires high levels of [physical activity] and limited sedentary time, frequent weight monitoring, and high levels of dietary restraint,” and weight regain is common, the authors summarize.
Other Options to Address Obesity, Hypertension
Weight-loss pharmacotherapies and metabolic surgery are other options to treat obesity and lower hypertension.
The statement reports that four drugs are approved by the US Food and Drug Administration (FDA) for long-term weight loss: orlistat (Xenical, Alli), phentermine/topiramate extended release (Qsymia), naltrexone/bupropion (Contrave), and liraglutide 3.0 mg (Saxenda). On June 4, the FDA approved a fifth drug, semaglutide (Wegovy).
The long-term effects of anti-obesity medications on blood pressure are mixed.
However, “prescription rates for these drugs remain low, likely because of limited insurance coverage and low levels of clinical proficiency with treating obesity,” Hall and colleagues write.
Metabolic surgery could be a weight loss option for certain patients, and it is associated with blood pressure lowering.
In the 100-patient Gastric Bypass to Treat Obese Patients With Steady Hypertension (GATEWAY) trial, published in Circulation in 2018, more patients in the Roux-en-Y gastric-bypass group than the control group (84% vs 13%) met the primary outcome of a ≥ 30% reduction in the number of blood pressure-lowering medications at 12 months while maintaining an office blood pressure < 140/90 mmHg.
Unanswered Questions, Future Research Directions
In 2015-2016, an estimated 18.5% of US children and adolescents age 2-19 years had obesity, the statement notes. Children with obesity have a twofold increased risk of incident hypertension, and those with severe obesity have an over fourfold increased risk of this outcome, compared with children who have a healthy weight.
Hall and colleagues emphasize that “as the prevalence of obesity continues to increase, hypertension and associated cardiorenal diseases will also increase unless more effective strategies to prevent and treat obesity are developed.”
They identified 17 unanswered questions (knowledge gaps) that can guide the direction of future research.
What new strategies and science-based guidelines are needed to curb the growing evidence of childhood obesity?
Does intentional weight loss with pharmacotherapy or metabolic surgery in childhood and early adulthood prevent hypertension and subsequent target organ damage in later life?
What is the optimal amount of time that clinicians should allow before recommending more aggressive weight management strategies (ie, anti-obesity medications or metabolic surgery) or hypertension strategies beyond lifestyle changes?
“To me,” Hall said, “addressing childhood obesity hypertension and determining optimal timing of anti-obesity therapies are the most important [issues].”
“Certainly, these therapies (ie, diets, medications, surgeries) have some risks, but we don’t have a clear understanding if their benefits outweigh these risks in younger obese people or whether initiating these therapies before the onset of target organ damage such as heart failure” outweigh the risks.
Hall has reported no relevant financial relationships. Disclosures for the other authors are listed with the article.
Hypertension. Published online September 20, 2021. Full text