Trajectories of Response to Acupuncture for Menopausal Vasomotor Symptoms: the Acupuncture in Menopause (AIM) study
Avis et al. · Menopause · 2017
Evidence Level
STRONGOBJECTIVE
Identify different patterns of response to acupuncture for menopausal hot flashes and characteristics that predict each response type
WHO
209 perimenopausal or postmenopausal women aged 45-60 with ≥4 hot flashes per day
DURATION
8-week analysis (up to 20 acupuncture sessions over 6 months)
POINTS
Individualized points based on traditional Chinese medicine diagnosis
🔬 Study Design
Acupuncture
n=170
Up to 20 acupuncture sessions over 6 months
Wait-list
n=39
Usual care for 6 months
📊 Results in numbers
Strong reduction in hot flashes (Group 1)
Moderate reduction (Group 2)
Minimal reduction (Group 3)
Increase in hot flashes (Group 4)
Women with clinically significant response
Percentage highlights
📊 Outcome Comparison
Reduction in hot flashes at 8 weeks
This study showed that acupuncture works differently for each woman with menopausal hot flashes. About 60% of women experienced significant improvement, with some seeing nearly complete relief in just 8 weeks. This means it is worthwhile to try acupuncture, since you could be among those who respond very well to treatment.
Article summary
Plain-language narrative summary
The AIM (Acupuncture in Menopause) study represents an important contribution to understanding how women respond individually to acupuncture for menopausal hot flashes. This pragmatic randomized clinical trial was conducted at two centers in North Carolina between 2011 and 2014, following 209 women aged 45 to 60 who experienced at least 4 hot flashes per day. The study design was innovative in using a 4:1 randomization, with 170 women receiving acupuncture and 39 in the wait-list control group. The protocol allowed up to 20 acupuncture sessions over 6 months, with frequency individually determined by the acupuncturist and the patient.
All four study acupuncturists were licensed with 8 to 33 years of experience and used traditional Chinese medicine diagnoses to individualize treatments. The main differentiator of this research was the use of finite mixture modeling to identify distinct response trajectories, instead of simply reporting group averages. This analysis revealed four distinct response patterns in the first 8 weeks of treatment. Group 1, comprising 11.6% of the sample (19 women), experienced an impressive 85.5% reduction in hot flash frequency.
Group 2, the largest with 47% of participants (79 women), achieved a substantial 46.8% reduction. Group 3, with 37.3% of the women (65 participants), showed only a modest 9.6% reduction. Surprisingly, a small Group 4 with 4.1% of participants (7 women) experienced a 100% increase in hot flashes. In the control group, 79.5% of women reported only a 10% reduction in symptom frequency.
Results showed that approximately 59% of acupuncture-treated women (Groups 1 and 2 combined) achieved a clinically significant reduction of at least 40% in hot flashes by 8 weeks. Importantly, women in Group 3, who initially did not respond well, showed late improvement, reaching a 23.3% reduction by the end of 26 weeks of treatment. The search for predictors of response revealed few significant factors. The number of acupuncture sessions in the first 8 weeks was the strongest predictor, with Group 4 (those who worsened) receiving significantly fewer treatments (mean 5.3 sessions) than the other groups (means between 8.3 and 9.1 sessions).
Traditional Chinese medicine diagnosis was also significant: women with kidney yin deficiency (a condition considered more chronic) were less likely to have a rapid and strong response, whereas those with diagnoses considered more acute responded better in the first weeks. Factors such as age, race, education, menopausal status, prior acupuncture use, treatment expectations, and psychological characteristics showed no significant association with response patterns. Clinical implications are substantial. The study provides robust evidence that acupuncture is effective for hot flashes in a significant majority of women, but with heterogeneous response patterns.
For practitioners, this suggests that women with certain TCM diagnostic characteristics may need more time to respond to treatment. For patients, it offers realistic hope that even those who do not respond initially may benefit with extended treatment.
Strengths
- 1Pragmatic design that simulates real clinical practice
- 2Innovative statistical modeling to identify response patterns
- 3High retention rate (92% at 8 weeks)
- 4Experienced and licensed acupuncturists
- 5Individualized protocol based on TCM
Limitations
- 1Small trajectory groups limited predictor analysis
- 2Analysis period of only 8 weeks
- 3Lack of sham acupuncture placebo group
- 4Few significant predictors identified
Expert Commentary
Prof. Dr. Hong Jin Pai
PhD in Sciences, University of São Paulo
▸ Clinical Relevance
The AIM study makes a methodologically mature contribution to the field of acupuncture in gynecology: instead of simply reporting group means — an approach that masks real clinical heterogeneity — the authors identified four distinct response trajectories in women with menopausal vasomotor symptoms. For clinicians who care for this population, this has direct implications: approximately 59% of patients achieve clinically significant reduction in hot flashes within 8 weeks, positioning acupuncture as a concrete therapeutic option for women who decline or have contraindications to hormone therapy, or for those who want an integrative adjunct approach. The individualized protocol based on traditional Chinese medicine diagnosis, conducted by acupuncturists with 8 to 33 years of experience, gives the design a real-world fidelity that many controlled trials cannot replicate.
▸ Notable Findings
The identification of four response trajectories using finite mixture modeling is the work's most sophisticated finding. Notable is the subgroup of 11.6% of participants who achieved an 85.5% reduction in hot flash frequency in just 8 weeks — a response that rivals first-line pharmacologic interventions. Equally relevant is Group 3, with a modest initial reduction of 9.6%, who progressed to 23.3% by the end of 26 weeks, suggesting that the absence of an early response is not a sufficient criterion for discontinuation. The diagnostic finding is clinically actionable: women with kidney yin deficiency — a pattern associated with chronicity in traditional Chinese medicine — responded more slowly, guiding the calibration of expectations and therapeutic planning. The number of sessions in the first 8 weeks emerged as a relevant predictor, with the worsening subgroup receiving an average of only 5.3 sessions.
▸ From My Experience
At the Pain Center of HC-FMUSP, we periodically treat women referred by gynecologists due to contraindications to or refusal of hormone therapy, and the pattern we have observed over the years is quite consistent with what the AIM study formalizes statistically. I usually notice the first signs of response between the third and fifth session; patients who reach the eighth session without any subjective improvement prompt me to reassess the TCM diagnosis and treatment density. The kidney yin deficiency diagnosis, common in this age group, indeed requires more sessions — generally I work with 12 to 16 sessions to achieve clinical stabilization, with subsequent monthly maintenance. I usually combine treatment with sleep hygiene counseling and, when the picture includes an anxiety component, with autonomic regulation techniques. The best-responder profile in my experience is the patient with more acutely installed climacteric syndrome, less chronicity, and good adherence to initial weekly follow-up — exactly the opposite of the established yin deficiency pattern that the article also identified as a predictor of slower response.
Full original article
Read the full scientific study
Menopause · 2017
DOI: 10.1097/GME.0000000000000735
Access original articleScientific Review
Marcus Yu Bin Pai, MD, PhD
CRM-SP: 158074 | RQE: 65523 · 65524 · 655241
PhD in Health Sciences, University of São Paulo. Board-certified in Pain Medicine, Physical Medicine and Rehabilitation, and Medical Acupuncture. Scientific review and curation of every entry in this library.
Learn more about the author →Medical disclaimer: This content is for educational purposes only and does not replace consultation, diagnosis, or treatment by a qualified professional. Some information may be assisted by artificial intelligence and is subject to inaccuracies. Always consult a physician.
Content reviewed by the medical team at CEIMEC — Integrated Centre for Chinese Medicine Studies, a reference in Medical Acupuncture for over 30 years.
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