U.S.
Food and Drug Administration
FDA Consumer magazine
May-June 2002
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Middle-aged Americans face a 90 percent chance of developing high blood pressure at some time during the rest of their lives, according to a new study supported by the National Heart, Lung, and Blood Institute (NHLBI).
However, the study also had some good news for Americans: The risk of developing severe degrees of high blood pressure has decreased in the past 25 years, due in part to improved treatment.
"Ninety percent is a staggering statistic and cause for concern," says Health and Human Services Secretary Tommy G. Thompson. "This finding should energize Americans to take steps to protect themselves against high blood pressure."
"Americans have to better understand their risk of developing high blood pressure," agreed NHLBI Director Claude Lenfant, M.D. "They cannot adopt a wait-and-see approach. If they do, chances are they will find themselves with high blood pressure and that puts them at increased risk for heart disease and stroke."
According to Lenfant, high blood pressure is easily diagnosed and can be prevented by adopting certain lifestyle measures--don't smoke, follow a healthy eating plan that includes foods lower in salt and other sources of sodium, maintain a healthy weight, be physically active, and if you drink alcoholic beverages, do so in moderation. For those who already have high blood pressure, it's important that they properly control it with these lifestyle measures and medication.
The study, based on data from the NHLBI's landmark Framingham Heart Study (FHS), appears in the Feb. 27, 2002, issue of the Journal of the American Medical Association. The National Institute of Neurological Disorders and Stroke also contributed support to the research.
High blood pressure, or hypertension, is a measure of the force of blood within blood vessels. It is recorded as two numbers--the systolic (the force of the blood as the heart beats) over the diastolic (the force of the blood as the heart relaxes between beats). The diagnosis of hypertension occurs if either or both are high--140/90 mm Hg or above.
"Lifetime risk" estimates the chance that someone at a given age will develop a particular disease during his or her remaining years of life. The FHS began in 1948 with 5,209 participants without cardiovascular disease who were ages 28 to 62. Participants underwent medical examinations every 2 years. The hypertension study includes 1,298 of the original participants--those who had not developed hypertension by 1975. Researchers calculated lifetime risk for two ages, 55 and 65.
Additionally, the researchers compared lifetime risk from two time periods, 1952-1975 and 1976-1998. They examined the results to see if any trends emerged in participants' risk for developing hypertension. Calculations were based on the current U.S. life expectancies for 55- and 65-year-olds, which are 80 and 85 years, respectively.
The investigators found that the lifetime risk of developing hypertension was about 90 percent for men and women at both ages. Further, more than half of the participants age 55 and about two-thirds of those age 65 went on to develop hypertension within 10 years. Both men and women had a nearly 60 percent chance of being prescribed blood pressure-lowering drugs.
Ramachandran Vasan, M.D., associate professor of medicine at Boston University School of Medicine and a coauthor of the study, cautions that the study was not ethnically diverse. He stresses that the lifetime risk of developing hypertension varies among individuals and depends on the presence of risk factors.
NHLBI information on cardiovascular disease and an interactive Web page, "Your Guide to Lowering High Blood Pressure," can be found online at www.nhlbi.nih.gov/hbp/.
An extract of the herb St. John's wort was found to be no more effective for treating major depression of moderate severity than a placebo in a recent government study.
The randomized, double-blind trial compared the use of a standardized extract of St. John's wort (Hypericum perforatum) to a placebo containing an inactive substance for treating major depression of moderate severity. The multi-site trial, involving 340 people, also compared the FDA-approved antidepressant drug Zoloft (sertraline) to a placebo as a way to measure how sensitive the trial was to detecting antidepressant effects.
"Many Americans use dietary supplements like St. John's wort for depression without consulting a physician," says principal investigator Jonathan R.T. Davidson, M.D., professor of psychiatry and director of the anxiety and traumatic stress program at Duke University Medical Center. "We felt there was a need to conduct a trial that could help us determine where St. John's wort fits in the overall management of depression."
The trial, funded jointly by the National Center for Complementary and Alternative Medicine (NCCAM), the National Institute of Mental Health (NIMH), and the Office of Dietary Supplements (ODS), all components of the National Institutes of Health, was launched in response to growing use of St. John's wort in the United States and a need for more definitive data on its use for different types of depression. The results were published in the April 10, 2002, issue of the Journal of the American Medical Association.
Although several smaller European studies have suggested that St. John's wort is useful in treating mild to moderately severe depression, experts who reviewed those studies concluded that they had limitations, and that more rigorous trials were needed before firm conclusions could be drawn. Thus, the NCCAM and its partners launched one of the first large-scale, multi-site clinical trials of St. John's wort in the United States.
"Our commitment is to apply exacting scientific methods to studying popular complementary and alternative medicine practices and to publish the results of such studies in critical peer-reviewed journals, so that the public and practitioners can make the most informed decisions about them," says Stephen E. Straus, M.D., NCCAM director. "This study represents one of our first 'down payments' on this commitment."
According to the NIMH, major depression affects approximately 9.9 million American adults age 18 and older in a given year and is a leading cause of disability in the United States. A person experiencing a major depressive episode, according to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), suffers from a depressed mood or loss of interest in normal activities that lasts most of the day nearly every day for at least two weeks. This mood can last longer if untreated. Other than depressed mood or loss of interest, symptoms include at least four of the following: significant weight loss or gain, sleep disturbances, agitation or unusual slowness, fatigue or loss of energy, feelings of worthlessness or guilt, lack of concentration, or recurrent thoughts of death or suicide.
Study participants' initial diagnosis and severity of depression were confirmed using three primary measures: the DSM-IV depression criteria, the Hamilton Depression Scale (HAM-D), and the Global Assessment of Functioning Scale (GAF). Participants who met DSM-IV criteria for major depression, who had initial HAM-D scores of 20 or higher, and who had at least moderately severe major depression according to the GAF, were recruited from 12 academic or community psychiatric research clinics across the country.
The study was conducted in two phases. The first 8-week phase, or acute phase, measured the number of people whose depression responded to treatment with St. John's wort (from 900 milligrams to 1500 milligrams per day), sertraline (50 milligrams to 100 milligrams per day), or placebo; this phase was the primary focus of the study. A second, or continuation, phase offered patients who had responded to their initial treatment another 18 weeks of therapy, which enabled researchers to gather data on longer-term use of the treatments. The preparation of St. John's wort used in this study is one sold and produced in Europe and used in many earlier, smaller depression trials.
"Overall, we found that patients taking either St. John's wort or placebo had similar rates of response according to scales commonly used for measuring depression," says Davidson. "And, although sertraline produced no greater effect than placebo on the primary measures, it fared better than placebo on the Clinical Global Impressions-Improvement scale and produced results consistent with its known benefits."
For additional information about this study, please consult "Questions and Answers: A Trial of St. John's Wort (Hypericum perforatum) for the Treatment of Major Depression," on the Internet.
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