Effect of Yoga on Objective and Subjective Menopausal Hot Flashes

Hot flashes and/or night sweats are the most common and troubling symptoms associated with
menopause. It is estimated that 64% to 87% of women report experiencing hot flashes for an
average of about 4 years. For many women, these symptoms are frequent and severe enough to
become debilitating and interfere with daily activities. They often occur at night,
disturbing sleep and leading to daytime irritability, fatigue and depressed mood. About
30-40% of menopausal women seek medical help for hot flashes. Relief from hot flashes has
been shown to be the primary reason that women initiate hormone therapy (HT).

HT is currently the gold standard for treatment of vasomotor symptoms. A Cochrane Database
systematic review showed a 75% reduction in hot flash frequency with hormone therapy compared
to placebo.1 However, recent findings from the Women's Health Initiative (WHI) trial indicate
that benefits of HT are outweighed by risks, such as coronary heart disease, stroke,
pulmonary embolism, breast cancer, and probable dementia. The wide publicity of the WHI
results has heightened women's concerns about taking HT and many women have sought
alternative treatments for hot flashes. These alternatives include other pharmaceutical
agents, herbal or dietary remedies, and behavioral therapies. Unfortunately, many of these
agents have a high incidence of side effects or have not been shown to be effective. A recent
NIH conference has called for more research on alternative treatments for hot flashes.

Behavioral interventions involving relaxation and slow deep, abdominal breathing have been
found to be useful for reducing mild- to moderate-intensity hot flashes. Although the
physiological mechanisms for the effectiveness of these interventions are not completely
understood, there is some suggestion that they may help reduce sympathetic activity which is
related to the narrowing of the thermoneutral zone. It is currently thought that hot flashes
are linked to a disruption in thermoregulation and that elevated levels of brain
norepinephrine may be the primary mechanism for altered thermoregulation. Breathing
techniques form the most integral core of any yoga practice which involves the combination of
physical postures (asanas), breathing (pranayama), and deep relaxation (savasana). Despite
suggestions that yoga may be beneficial for the relief of hot flashes, these potential
benefits have not been well-studied.

To date, treatment efficacy for hot flashes has been limited to self-reported, subjective
symptoms. While subjective hot flashes are important from a woman's perspective in her
decision-making with respect to treatment, research has shown that they can be influenced by
mood and reporting biases. Objective measures are not subject to these biases and have the
advantage of providing insight as to whether an intervention has a physiological effect.
However, until recently, reliable objective measures that could be used in an ambulatory
setting were not available. NCCAM has recently funded the development of new technologies to
monitor objective hot flashes in an ambulatory setting, as measured by skin conductance. This
technology greatly enhances our ability to fully evaluate the impact of treatment on both
subjective and objective hot flashes.

The primary goal of this R21 pilot grant is to obtain preliminary data on the efficacy of
Integral Yoga for reducing self-reported menopausal hot flashes. Secondary aims are to
determine the impact of yoga on objective hot flashes and other outcomes and study
feasibility. Our primary hypothesis will be a greater reduction in subjective hot flash
frequency and severity in the yoga group than in two control groups. Secondary outcomes will
include a greater reduction in objective hot flash frequency; a greater decrease in hot flash
interference; and greater improvement in sleep, other symptoms, mood, perceived stress, and
overall quality of life in the yoga group.

Inclusion Criteria:

- At least 2 months since last menses

- Age 45-58 years

- Moderate to severe vasomotor symptoms for at least 4 weeks (at least 4/day on average)

- Self-reported general good health

- Adequate English to understand informed consent form, questionnaires, and converse
with study staff

- Agree not to use pharmaceutical agents for treating hot flashes during the study

Exclusion Criteria:

- Hormone therapy use within 12 weeks prior to study screening, including systemic
estrogen, progestin or androgen therapy

- Selective estrogen receptor modulator (Evista® and Novaldex®) or aromatase inhibitor
use within 6 months

- Cancer at any time

- Untreated thyroid disease

- Initiation of herbal or nutritional supplements for hot flashes within the past 4
weeks

- Significant psychiatric disorder, including regular use of antidepressants or
anxiolytics

- Regular use of clonidine or Bellergal® within the past 12 weeks

- Any past use of yoga for hot flashes

- Yoga or Acupuncture for any reason within the past 3 months