Complementary Alternative Therapies for Hypertension: Is It Worth It?

A survey performed in the 1990s in 831 respondents regarding the use of complementary alternative therapies (CAM) for their medical problems demonstrated that 79% perceived that the combination of CAM and their physicians’ treatment was superior to either one alone. The perceived confidence in CAM providers was not substantially different from confidence in medical doctors.¹ Among the 831 respondents who in the past year had used a CAM therapy and seen a medical doctor, 63% to 72% did not disclose at least one type of CAM therapy to the medical doctor. The primary reason for this lack of disclosure being that "It wasn't important for the doctor to know" (61%) or "The doctor never asked" (60%).

More recently a secondary analysis of the 2007 United States National Health Interview Survey (NHIS), reviewed CAM use.² Chiropractic or osteopathic manipulation (8.4%) and massage (8.1%) were most commonly used; acupuncture was used by 1.4% and naturopathy by 0.3% of respondents. Substantial proportions of respondents reported using CAM for wellness and disease prevention and informed their physician of its use. The results of this survey indicate that CAM users present with common cardiovascular risk factors including obesity, hypertension, and other co-morbidities that are priority public health issues. Most physicians, CAM users, and the public, in general, are not aware of the evidence-based data surrounding the use of various CAM procedures, medications, or devices. Thus, there is a clear need to provide the CAM health care professionals, patients, and the medical community evidence-based data to optimize health promotion. Given the public perception, the dissemination of such data during CAM encounters may provide an opportunity to coordinate health promotion and prevention messages with the patients' primary care providers.

Data over the past half century emphasize healthy lifestyle in order to reduce cardiovascular risk. This has not only included well-known recommendations such as reduced salt intake and smoking cessation, but also a focus on weight loss and aerobic exercise. All these methods have proven efficacy for reducing arterial pressure and markedly delaying the development of hypertension in genetically prone individuals, yet people seek a variety of CAM approaches that are unproven or untested to reduce risk ).³

Many well-designed clinical trials document that dietary sodium reduction reduces blood pressure in people with a family history of hypertension regardless of whether they are prehypertensive or hypertensive, and reduces stroke risk.⁴ In addition, limiting sodium intake can enhance the response to most antihypertensive drugs by magnifying their effect and limiting potassium depletion. Conversely, persistent high sodium intake blunts the effects of antihypertensive agents.⁵

Many trials also support the concept that institution of regular aerobic exercise can augment blood pressure reduction, associated with dietary modifications. Although the benefits of sodium restriction, diet, and exercise on blood pressure level are well documented, the effects of these interventions on cardiovascular morbidity and mortality require prolonged adherence, large sample sizes, and long-term follow-up. The best available data do show a trend toward cardiovascular risk reduction, however.^6,7

Several other modalities of alternative therapies have emerged for preventing arterial pressure increases but not all are well tested. The estimates of adults using alternative therapies vary by socioeconomic and educational status as well as availability of selected methodology, although this has not been studied extensively. Most reports suggest that people with higher incomes used these therapies more commonly.¹ However, it is clear from the aforementioned data that non-traditional, non-drug treatments are used by a growing segment of the population for prevention and treatment of hypertension. Moreover, the use of these CAMs has grown at a pace that exceeds the amount of data documenting their efficacy.

The most frequently reported reasons for using CAM are suggestions from friends or colleagues, attempts to avoid potential side effects of pharmacological treatments, or failure of pharmacological treatments to control arterial pressure satisfactorily).¹ Given the diffuse spectrum of treatments, the American Heart Association (AHA) has now published an evidence-based scientific statement outlining the currently available CAMs so that healthcare professionals can make an informed decision about a type of CAM.⁸

The writing group provided a class of recommendation for the implementation of CAM in clinical practice based upon the available level of evidence from the published literature. The grading of the evidence is consistent with what the AHA has previously published, Class I, Level of Evidence A being a useful intervention defended by randomized trials and contrasting to a Class III C recommendation, meaning not useful with no evidence to support and perhaps harm if used. The authors acknowledged consistent gaps in evidence about CAM approaches and clearly state that CAM approaches should be considered adjunctive therapies to conventional treatments for managing high blood pressure.

Although evidence did not unveil any identifiable risks when these treatments are implemented, there is little-to-no evidence from well-designed randomized controlled clinical trials that these approaches reduce cardiovascular events in hypertensive patients. Conversely, some of these alternative approaches were valuable in maintaining blood pressures within an acceptable range (i.e., <140/90 mmHg in normotensive people). Thus, the consensus of the writing group was that it is reasonable for all patients with blood pressure levels higher than 120/80 mm Hg to consider a trial of alternative approaches as adjuvant methods to lower blood pressure.

Among the reviewed approaches, only dynamic aerobic and resistance exercise and device-guided breathing received a class recommendation I A or II A, respectively, for blood pressure--lowering.⁸ Thus, such approaches should be strongly encouraged in hypertensive patients who want additional nonpharmacologic therapy as well as those who want to try and maintain blood pressure below 140/90 mmHg.

Aerobic exercise reduces arterial stiffness and improves endothelial function by increased bioavailability of nitric oxide and improvement of insulin resistance and other metabolic parameters.⁹ However, in the Atherosclerosis Risk in Communities study, self-reported physical activity showed only a weak and inconsistent relationship to reduced arterial stiffness).¹⁰ The magnitude and type of activity was not specified. Thus, these findings reflect limitations in self-report measures of physical activity. This limitation in specificity of the type of exercise is one of several inherent limitations in the literature reviewed by the scientific committee.

Several prerequisites for the quality of data assessment are not always met in many studies. Examples of these data limitations include assessment of adherence to the training program, attention to changes in other lifestyle factors, detailed description of the duration and energy expenditure of each exercise, and dose-response and lack of blinding or automated measurements. Furthermore, only a small number of studies conducted an intention-to-treat analysis, which makes it impossible to quantify the effects of study withdrawals on primary endpoints.

The potential weaknesses, heterogeneity and potential publication bias of the studies on CAM, increase the number of Class II recommendations (i.e., subject to uncertainties). Therefore, the guidance can only be as good as the data; hence, with the exception of the aforementioned recommendations the remaining treatment approaches examined were predominantly Class II with some behavioral therapies, Yoga and Acupuncture being Class III B or C showing no benefit.

The committee presents a very nice algorithm as to what alternative therapies are appropriate and at what stage of hypertension they should be instituted. It is clear that these approaches are appropriate in the very early stage of hypertension prior to treatment and as an adjunct to mono or single pill combination therapy rather than useful in more severe forms of the disease. It should be noted that other forms of CAM for hypertension such as certain roots and herbs from Asia were not discussed, as there are no clinical trial data.