UBC Reports | Vol. 50 | No. 4| Apr.
Plant-based Hormone Offers New Hope for Hot Flushes
UBC study tests safer replacement for estrogen
By Hilary Thomson
Imagine that your heart starts pounding, your skin temperature
suddenly spikes and you break out in a sweat that wakes you
up at night and forces you to fling off clothing during the
Now imagine these embarrassing and sometimes debilitating
personal heat waves persisting for years.
This is the world of night sweats and hot flushes -- the
characteristic mid-life change experienced by about 75 per
cent of women in perimenopause and the early years after menopause.
In the first study of its kind, UBC researchers are testing
a manufactured hormone that might provide safe and effective
relief for tens of thousands of women troubled by these symptoms.
Christine Hitchcock, a researcher at the Centre for Menstrual
Cycle and Ovulation Research (CeMCOR), is testing the effectiveness
of Prometrium®, the commercial name for a plant-based
manufactured hormone that is chemically identical to the progesterone
produced by the body. Approximately 60 women will use a placebo
or Prometrium® for four months to determine if the drug
can control hot flushes as well as improve blood vessel function
and help prevent heart attack.
Betty-anne Dempsey is a participant in the trial. The 51-year-old
had been on hormone replacement therapy (HRT) for hot flushes
that were leaving her sleep-deprived. She stopped using HRT
because of a family history of heart disease and had tried
herbal remedies without success.
“I got involved with the study because I want some
relief but I also want to make sure I’m well,”
she says. “Participating in the study gives me more
insight into my own health.”
Until recently, hot flushes were treated with estrogen.
Many women stopped estrogen therapy, however, after the results
of the Women’s Health Initiative Study announced in
July 2002 that estrogen with low dose progestin (a synthetic
form of progesterone) increased risk of pulmonary embolism,
heart attack, stroke and breast cancer.
“The importance of safe and effective therapy becomes
even more clear as the dust settles from the trials of menopausal
hormone therapy. Early studies suggested that progestins were
effective in hot flush control but this is the first study
to test natural oral progesterone for these symptoms,”
says principal investigator Jerilyn C. Prior, a professor
of endocrinology who is scientific director of CeMCOR, a part
of UBC’s Dept. of Medicine and the Vancouver Coastal
Health Research Institute (VCHRI).
In addition to learning about the drug’s effect on
hot flushes, Hitchcock and Prior will examine its effects
on cholesterol, blood pressure, blood sugar and weight gain.
They are particularly interested in blood vessel function
and will use a forearm blood flow test that can predict risk
of cardiovascular disease. Participants will also keep a daily
menopause diary to record the incidence and severity of flushes
and sweats as well as other experiences such as insomnia,
depression and fluid retention.
“We want to be able to give women a choice and a more
targeted therapy for hot flushes. Also, this study will provide
important information about the effects of progesterone alone
on cardiovascular health,” says Hitchcock.
Scientists do not know the exact mechanism of hot flushes.
They believe that flushes originate in the hypothalamus --
the area of the brain that integrates stressors. Somehow,
the body registers that its core temperature is too hot. It
produces the flushes to get hot blood away from the core and
move it to the skin’s surface to cool down.
The average age of onset for hot flushes is 48. They can
be triggered by warm environments, hot or spicy food, alcohol,
caffeine or stress. An individual flush usually lasts from
a few seconds to 30 minutes or an hour and may happen a few
times a day or once a week. The phenomenon can continue for
four to nine years surrounding the time of the last menstrual
Men who have been castrated because of testicular cancer or
those receiving hormone therapy for prostate cancer may also
experience flushes and sweats.
For more information on hot flushes, visit the CeMCOR website
To learn more about the trial, click on ‘get involved’.
The study has been initiated by researchers and is not sponsored
by a drug company.
CeMCOR distributes information directly to women about changes
through the life cycle, from adolescence to menopause.
VCHRI is a joint venture between UBC and Vancouver Coastal
Health that promotes development of new researchers and research