IOM Report Calls Hypertension a "Neglected Disease"

Jacquelyn K. Beals, PhD

February 22, 2010

February 22, 2010 — Hypertension is a "neglected disease," according to a report released today by the Institute of Medicine. Despite high blood pressure being the cause of death in 1 of 6 US adults, and the greatest single risk factor for deaths from cardiovascular disease, millions of Americans are developing, living with, and dying from hypertension. The decade from 1995 to 2005 saw a 25% increase in the death rate from high blood pressure.

"We are failing to translate our public health and clinical knowledge into effective prevention, treatment, and control programs," observed the Committee on Public Health Priorities to Reduce and Control Hypertension in the US Population. Their report offers recommendations for changes by individuals, physicians, and policies to prevent and control high blood pressure and associated health problems.

It's time to add hypertension to the list of neglected diseases, David W. Fleming, MD, chair of the Committee on Public Health Priorities to Reduce and Control Hypertension in the US Population, said during a February 22 briefing at the National Academies' Keck Center in Washington, DC.

The committee's recommendations include strengthening collaboration between the Centers for Disease Control and Prevention and related agencies to include hypertension among their lifestyle improvement efforts, monitoring and reducing sodium intake, improving the reporting of hypertension to determine general population and subgroup trends, and improving the quality of care and removing economic barriers to effective antihypertensive treatments.

Down With Sodium, Up With Potassium

The report notes that 87% of adults in the United States ingest more than 2400 mg/day of sodium (1500 mg/day is recommended for individuals middle-aged or older, blacks, or those with hypertension). A strategy recommended to the Division of Heart Disease and Stroke Prevention is the use of potassium/sodium chloride combinations to simultaneously reduce sodium and increase potassium intakes.

Using estimates based on 31 trials of sodium reduction, and data indicating that 87% of the American population consumes excess sodium, the prevalence of hypertension can be expected to decrease 5% to 8% if everyone currently on a high-salt diet decreased their salt intake by about 4.5 g/day.

"Over 8 in 10 Americans eat more salt in their diet than is recommended. And almost everyone consumes too little potassium," said Dr. Fleming. "The Committee recommends that CDC take a strong and active leadership role working with industry to implement strategies to reduce salt in our diet,...promote the intake of potassium-rich fruits and vegetables, and also consider advocating for the greater use of potassium/sodium salt combinations as a means of simultaneously reducing sodium and increasing potassium intake."

The effects of potassium supplementation have varied across studies, but data indicate that if the entire population increased its potassium intake to 4700 mg/day, prevalence of hypertension could be reduced as much as 4% to 7%. The proportion of hypertension currently attributed to low potassium intake is around 17%.

High potassium intake can, however, itself be problematic. Lawrence J. Appel, MD, MPH, a member of the American Society of Hypertension and professor of medicine at John Hopkins University, Baltimore, Maryland, who attended the briefing, told Medscape Cardiology, "In general it appears that diets that are both low in sodium and rich in potassium are the best diets in terms of lowering blood pressure [and] controlling hypertension, [but] there are some caveats. There are patients with kidney disease, but it has to be pretty advanced before you get to problems with potassium. And there are patients with advanced heart failure where you're concerned about it. Typically those are patients that are being cared for and monitored, so...certainly for the general population, but also even for most patients with hypertension who don't have the problems I mentioned, you're not going to get any problems from dietary potassium," Dr. Appel said.

The committee recommends that the Division of Heart Disease and Stroke Prevention and related agencies focus on preventing hypertension by reducing overweight and obesity, increasing physical activity, reducing sodium intake, and increasing intake of fruits, vegetables, and whole grains, especially foods rich in potassium.

Nonadherence as a Clinicians' Problem

The Division of Heart Disease and Stroke Prevention was also urged to identify better ways of analyzing and reporting data on hypertension over time, establishing norms for data collection analysis and reporting of these data, with a particular focus on children, elderly, minorities, and socioeconomic groups for whom fewer data are available.

Of particular interest were the IOM committee's findings on patients' nonadherence to treatment and physicians' nonadherence to guidelines laid out by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Although the JNC advises starting treatment when systolic blood pressure exceeds 140 mm Hg or diastolic blood pressure exceeds 90 mm Hg, many physicians are much less aggressive. Most cases of uncontrolled hypertension were in older adults with mild systolic hypertension and with frequent contact with their physicians and access to healthcare.

"It was quite striking, actually, that clinicians do a pretty good job of controlling diastolic blood pressure. It's systolic blood pressure that they're not aggressively treating, and especially isolated systolic hypertension," said committee member Corinne Husten, MD, MPH, former executive vice president for Program and Policy, Partnership for Prevention, Washington, DC. "There could be a variety of reasons. When I was in medical school we were taught, 'You don't treat a high top number because older people need that head of steam to get the blood through those hardened arteries. And the data since then have shown that's really not true."

Dr. Husten noted that clinicians may also be concerned about the adverse effects of medication in older people, and questions about whether full dosage should be used. It will be important to determine the reasons that physicians are not adhering to current guidelines, she said. No data currently address that issue.

Hypertension as a Sentinel for Healthcare Effectiveness

The IOM report also highlighted the financial barriers to lowering blood pressure. Studies have shown that cost of medications to patients is significantly related to patient adherence, especially evident in patients with low income, chronic illness, and multiple prescriptions. The committee recommendation advocates lowering or eliminating costs of antihypertension drugs under Medicare and Medicaid.

At the policy level, recommendations urge state and local public health agencies to emphasize populationwide approaches and to integrate hypertension prevention into programs to influence obesity prevention, increase physical activity, and encourage healthy diets.

On a more positive note, the IOM committee suggested that hypertension can serve as a "sentinel" for program evaluation in public health treatment of a chronic disease and reduction of healthcare disparities. Hypertension has the "advantages" of being objectively diagnosed and measured, low-cost treatments are available, results can be easily measured and reproduced, and the disease responds rapidly to interventions.

"Here is a place where, as a result of new work that has been done, we now not only think we can make a difference, but we have scientific studies in both the public health arena and in the clinical arena that show we can make a difference," concluded Dr. Fleming.

The full text of the report is available at http://www.nap.edu.

After completion of the Report, Dr. Husten joined the US Food and Drug Administration as senior medical advisor, Center for Tobacco Products (October 2009). Dr. Appel has done clinical research and trials that led to some conclusions of the report and has given invited talks at pharmaceutical companies, but does not feel he has conflicts of interest. One of his National Institutes of Health–sponsored studies received partial support from King-Monarch, which provided medication.

Institute of Medicine. A Population-Based Policy and Systems Change Approach to Prevent and Control Hypertension. Washington, DC: The National Academies Press. February 22, 2010.

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