Do Hot Flashes Increase Hip Fracture Risk?

Hot flashes, also known as hot flushes, are a symptom of the changing hormone levels that come with menopause.

According to a new study from the University at Buffalo, women who have moderate to severe hot flashes and night sweats during menopause tend to have higher rates of hip fracture.

Also, those women with these symptoms are likely to have lower bone mineral density than women the same age without menopausal symptoms.

Thousands of women were followed by the study for eight years. Adjustments were made for age, body mass index, and demographic factors.

Researchers found that women who reported moderate to severe hot flashes at enrollment had a considerable reduction in the bone density in the femoral neck region of their hips over time. They were also almost twice as likely to have a hip fracture during the follow-up period.

Hot Flashes and Night Sweats

We knew that during menopause, about 60 percent of women experience vasomotor symptoms (VMS), such as hot flashes and night sweats. They are among the most bothersome symptoms of menopause and can last for many years,” said Jean Wactawski-Wende of the University at Buffalo School of Public Health and Health Professions.

The study involved data from 23,573 clinical trial participants, aged 50 to 79, who were not then using menopausal hormone therapy nor assigned to use it during the trial. Baseline and follow-up bone density examinations were done on 4,867 of these women.

It also was known that osteoporosis, a condition in which bones become structurally weak and more likely to break, afflicts 30 percent of all postmenopausal women in the United States and Europe, and that at least 40 percent of that group will sustain one or more fragility fractures in their remaining lifetime. What we did not know,” says Wactawski-Wende, “was whether VMS are associated with reductions in bone mineral density or increased fracture incidence.”

Wactawski-Wende is a professor in the department of epidemiology and environmental health, as well as the department of obstetrics and gynecology in the UB School of Medicine and Biomedical Sciences.

Women who experience vasomotor menopausal symptoms will lose bone density at a faster rate and nearly double their risk of hip fracture,” she says, “and the serious public health risk this poses is underscored by previous research that found an initial fracture poses an 86 percent risk for a second new fracture.”

Fast and Slow Hot Flashes

Some menopausal women may experience both standard hot flashes and a second type sometimes referred to as “slow hot flashes” or “ember flashes”.

The standard hot flash comes on rapidly, sometimes reaching maximum intensity in as little as a minute. It lasts at full intensity for only a few minutes before gradually fading.

Slow ember flashes appear almost as quickly but are less intense and last for around half an hour. Women who experience them may undergo them year round, rather than primarily in the summer, and ember flashes may linger for years after the more intense hot flashes have passed.

Resources:

Carolyn J. Crandall, Aaron Aragaki, Jane A. Cauley, JoAnn E. Manson, Erin LeBlanc, Robert Wallace, Jean Wactawski-Wende, Andrea LaCroix, Mary Jo O’Sullivan, Mara Vitolins, and Nelson B. Watts
Associations of Menopausal Vasomotor Symptoms with Fracture Incidence
The Journal of Clinical Endocrinology & Metabolism  DOI: http://dx.doi.org/10.1210/jc.2014-3062

Shanafelt, Tait D.; Barton, Debra L.; Adjei, Alex A.; Loprinzi, Charles L. (November 2002).
Pathophysiology and Treatment of Hot Flashes“.
Mayo Clinic Proceedings 77 (11): 1207–1218. doi:10.1016/S0025-6196(11)61811-9