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Rapid Responses to:
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Electronic letters published:
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif){kind=icon}
Treatment of Vasomotor Symptoms of Menopause with Black Cohosh, Multibotanicals, Soy, Hormonal Thera
Author's Reply
Are conclusions of the HALT-study on herbal remedy really sound?
Untitled
Dosage Low, Conclusions Sweeping
A misguided trial of Cohosh
Interpretation of the "negative" result
why between-subjects design?
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Katherine M Newton, Ph.D Group Health Center for Health Studies, Susan D. Reed, MD, MPH and Andrea LaCroix, Ph.D
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newton.k{at}ghc.org Katherine M Newton, et al.
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We do not agree with Mr. Krueger that a within-subject design would have been preferable. A valid crossover study requires sufficient time for the effects of one drug to "wash out" before treatment on a second drug is begin. The time needed for the effects of herbal treatments to wash out is unknown so a crossover study would be subject to the criticism that the effects of one drug contaminated the effects of the others. Exposing each woman to all treatments would have required 14 months of participation, introducing unnecessary logistical and analytic complexity. This approach would have negated our opportunity to evaluate bone mineral density and to examine adverse events associated with longer duration of therapy. Menopausal symptoms change through time, further complicating the interpretation of crossover studies. Dr. Ge raises one of the principle limitations of many studies of alternative therapies for menopause symptoms, the use of generalized scales to summarize the menopause experience. These scales use a single question or small sets of questions for each outcome (hot flashes, mood, etc). As Dr. Ge observed, changes in scale scores are usually driven by vasomotor symptoms. We believe it is preferable to use validated, outcome- specific instruments (hot flash diaries and sternal skin conductance for vasomotor symptoms, PHQ-9 for depression, etc). Our study was powered to rule out differences between treatment groups greater than 1.5 vasomotor symptoms per day, a change we consider quite small. One cannot conclude that there was a large placebo effect in the HALT study simply because symptoms decrease from baseline to month 3 in the placebo group. Subjects were excluded if they did not have at least 2 symptoms per day. We expected symptoms to decline from baseline to month 3 due to regression to the mean. Also, change in the placebo group was minimal from months 3 to 12 so it is incorrect to claim that there was a placebo effect after month 3. Black cohosh was standardized to 2.5% triterpine glycosides. The doses we used were those most frequently used by naturopathic physicians in Seattle at the time, were consistent with manufacturer recommendations, and are considerably higher than doses currently recommended by many manufacturers (40-80mg). We are unaware of recommendations for doses as high as 1000-1500mg and consider such a practice inadvisable. Dr. Byron may be confusing the dose of dried root with that for standardized extract. Respectfully, Katherine M. Newton, PhD Associate Director for Research Group Health Center for Health Studies 1730 Minor Ave., Ste 1600 Seattle, WA 98101 Phone: 206-287-2973 FAX: 206-287-2871 Email: newton.k@ghc.org Susan D. Reed, MD, MPH Associate Professor of Obstetrics and Gynecology School of Medicine University of Washington Seattle, WA Andrea Z. LaCroix, PhD Professor of Epidemiology Public Health Sciences Division, Fred Hutchinson Cancer Research Center Seattle, WA Conflict of Interest:None declared |
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Katherine M. Newton, PhD Group Health, Susan D. Reed and Andrea Z. LaCroix
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newton.k{at}ghc.org Katherine M. Newton, et al.
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Author’s Reply We would like to reply to two points made in this review. First, is the issues of the select nature of the populations we studies, and resulting generalizability. We do not disagree with this point which applies to virtually any study. However, it is important to note that we made conscious choices to increase the generalizability compared to many of the currently published studies. We included women who were in the menopause transition as well as post-menopausal women, we included women with as few as 2 hot flashes per days vs. the 7 or more per day that is often required, and we included women with and without a uterus. The fact that our results were consistent across these different characteristics is, we believe, a point in favour of generalizability. It should also be clarified that we did not mail 150,000 letters to women with qualifying symptoms. Rather, the mailings went to presumably age-eligible women, but we could not target those with hot flashes specifically. And women received 2-3 mailings over time, so the number of women approached was closer to 60,000. The large number of mailings was necessary because the number of women with qualifying hot flashes who were willing to accept randomization in a clinical trial, and not already taking an alternative therapy or HT, is relatively small. The population base is far superior to studies enrolling women who present for symptoms, who represent just the tip of the iceberg. It is suggested that a better evaluation of compliance with the soy intervention would have been urine or plasma phytoestrogens. We agree, and we will be publishing these results in the future. Respectfully, Katherine M. Newton, PhD Associate Director for Research Group Health Center for Health Studies 1730 Minor Ave., Ste 1600 Seattle, WA 98101 Phone: 206-287-2973 FAX: 206-287-2871 Email: newton.k@ghc.org Susan D. Reed, MD, MPH Associate Professor of Obstetrics and Gynecology School of Medicine University of Washington Seattle, WA Andrea Z. LaCroix, PhD Professor of Epidemiology Public Health Sciences Division, Fred Hutchinson Cancer Research Center Seattle, WA Conflict of Interest:I am the first author of this manuscript. |
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Robert E. Kaeufeler, Medical Doctor Max Zeller Soehne AG
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robert.kaeufeler{at}zellerag.ch Robert E. Kaeufeler
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It is important that the authors’ claim regarding the efficacy of black cohosh be considered in the context of an unusually high placebo response and an unclearly defined black cohosh dose. Even allowing for natural symptom regression over time, the placebo response in this study warrants further scrutiny. There was a consistent reduction in symptoms in the placebo group in the first 6 months (reduction from baseline in all other groups became stable after 3 months) and over a 1-year period only one patient in this group discontinued due to lack of symptom relief. This drop out rate was even proportionally less than among patients in the HRT group. Unusually high placebo responses in clinical trials can mask true drug responses and may be due to flaws in study design or implementation. Changes introduced following the publication of the WHI study led to 16 patients being unblinded and may also have been responsible for marked baseline differences observed among treatment groups, in particular between the HRT group and the others. The validity and clinical relevance of the findings of this study may also be undermined by the dosage and type of black cohosh extract used. Although the authors state that the effects of herbal products may be sensitive to dose and extraction method, they have not addressed these issues in the study. The amount of triterpene glycosides which is discussed constitutes not at all to the active substance of black cohosh and authors have not specified the extract used in the study according to current and international regulatory guidelines and standards [1]. This study therefore does not negate the results of previous studies that have demonstrated the efficacy of black cohosh. The WHI study had previously shown an increased risk of cardiovascular disease and breast cancer in women using HRT [2]. In light of new evidence which suggest that the recent fall in the incidence of breast cancer rates in the United States may be due to a reduction in hormone use [2], black cohosh should continue to be considered an alternative treatment of menopausal symptoms. 1. CPMP/QWP/2819/00 Rev 1 2. Rossouw, J.E., et al., Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial. Jama, 2002. 288(3): p. 321-33. 3. Ravdin, P.M., et al. A sharp decrease in breast cancer incidence in the United States in 2003. in San Antonio Breast Cancer Symposium. 2006. Conflict of Interest:The author is Medical Director of Max Zeller Soehne AG, Switzerland. The company produces its own black cohosh extract Ze 450. |
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yarim gupta, MD mid western univ
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yg567{at}yahoo.com yarim gupta
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Was an excellent article, clearly illustrating the benefits of Black Cohosh, Multibotanicals, Soy, Hormone Therapy in menpause. My congrats to the authors. |
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Jonathan R. Byron, Ph.D. none
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jbyron{at}clearwire.net Jonathan R. Byron
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The dosages used in this study (160 mg daily of black cohosh root or 200 mg daily of black cohosh and other botanicals) are much lower than that taken by many women. Some commonly used supplements contain 500 mg or more of C. racemosa root per capsule, and multiple capsules are taken per day. It is not unusual to see a daily dose that is ten times larger than that used in this experiment. Assuming there is a dose-dependency to previously demonstrated phytoestrogen properties of black cohosh, it is unfortunate that this study only looked at relatively low doses. This study made a sweeping conclusion (that black cohosh "shows little potential as an important therapy for relief of vasomotor symptoms") that may or may not be true, but which is not supported by the study design. Research to evaluate ethnobotanical practices should start with a better understanding of those practices. Conflict of Interest:None declared |
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Gerald Shapiro, MD, M.F.Hom (London) Private medical practitioner, Homeopathic drug pictures - Margaret Tyler
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sybger{at}bezeqint.net Gerald Shapiro, et al.
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Neither black nor blue Cohosh is indicated in any herbal/homeopathic text book for menopausal vasomotor symptoms sothat this trial is of no value in this respect. Unfortunately not one of your auhors is mentioned as being a fully qualified physician as well as a fully qualified and certified homeopath, in which case it would have been a far more useful to have compared homeopathically prepared Sepia,Sulphur,Lachesis or Pulsatilla. The time is really long overdue for orthodox medicine to take a genuine look at the enormous potential for other therapies Conflict of Interest:The misunderstanding of herbal/homeopathic potential |
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Baoming Ge, MD, MClSc China Clinical Trials Coordination Center
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gebaoming{at}126.com Baoming Ge
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Dear Editors I read the paper with interest about the excellent work completed by Dr. Newton and her colleagues. We have just finished a pilot study of a black cohosh ethanol abstract in Beijing and are on the track of a national wide multi-centered RCT. The double-blinded pilot study enrolled 120 Chinese women with climacteric symptoms who were stratified into perimenopausal and postmenopausal arms, according to the standard of STRAW. Each arm was divided into 3 interventional groups, i.e. black cohosh (BC) low dose (1# bid), BC high dose (1# tid) and placebo, with 20 cases in each group. The primary outcome was Kupperman Index (KI) evaluated before the study and at the 2 and 4 weeks after the treatment. We also used menopause rating scale (MRS) as secondary outcome when it was first introduced in China and validified by this study. Although some of the results of this pilot study were "negative" (even there existed difference between BC and placebo groups), similar as shown in Dr. Newton et al's study, we were very careful to accept the null hypothesis, which we believed that the sample size we calculated before the study was not powerful enough to detect the difference. I've noticed in Dr. Newton et al's study that they calculated the sample size based on an assumption that the effect of herbs was halfway of HRT. It is not surprised to see that the black cohosh group failed to show a "P<0.05" when it didn't reach the standard effect size even though the 95% CIs shifted to the left side of zero and inferred a small sample size. Seems Dr. Altman's words ring again beside our ears absence of evidence is not an evidence of absence. I have also noticed that Dr. Newton and her colleagues also admitted that their study result didn't rule out the differences between treatment groups smaller than 1.5 vasomotor symptoms per day. We have never used Wiklund Vasomotor Symptom Subscale in China. But we found an interesting result in our study when we used both KI and MRS as outcomes, of which the KI seemed more "sensitive" to detect the treatment effect than MRS. We postulated that it was possible due the "weight" factor given to the score of vasomotor symptoms in KI which might "amplify" the effect comparing scored by MRS. It is interesting to know if any other researchers find similar phenomena. Our study showed that the BC treatment brought more adverse events than placebo to the participants, mainly headaches. It was also shown in many other studies on BC. I was surprised to find that BC treatment had similar safety profile as placebo in Dr. Newton et al's study. We used a pharmaceutical product with major components specified, provided by a local manufacturer. Dr. Newton didn't mention whether the components contained in the BC product were standardized. We appreciate that Dr. Newton or any other medical professionals with experience of using BC may share information with us. Sincerely Yours Dr. Baoming Ge Reference Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ 1995;311:485 Conflict of Interest:Dr. Ge is the medical director of a CRO, located in Beijing, China. |
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Jonathan P. Krueger none
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jpk{at}rawbw.com Jonathan P. Krueger
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Is there some reason a within-subjects design was not used? It would appear to be suited to the phenomenon, which is reversible and observable within months. Why not have all subjects experience all conditions, say two months per condition, ordered at random for each subject?The power would be better, the results cleaner, and we'd be able to answer a question this study cannot: do some subjects repond reliably, even if the overall response is weak? Conflict of Interest:None declared |
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