Are Hot Flashes Linked to Brittle Bones?

Menopausal symptoms like hot flashes and night sweats could be more than just an inconvenience—they could predict a greater likelihood of brittle bones, according to a new study in the Journal of Clinical Endocrinology & Metabolism.

“Compared with women who did not have hot flashes, women who reported having hot flashes at the beginning of the study had a higher risk of hip fracture during the 8 years of observation,” says lead study author Carolyn J. Crandall, MD, MS, of the David Geffen School of Medicine at the University of California, Los Angeles. “Women who reported hot flashes also had lower bone density than women who did not have hot flashes.”

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According to the researchers, this is the first large cohort study to examine the relationship between menopausal symptoms and bone health in menopausal women. Crandall and her colleagues examined data from 23,573 participants in the Women’s Health Initiative Clinical Trial—women ages 50 to 79 who were not using menopausal hormone therapy.

They also looked at data from 4,867 patients from the trial who participated in a sub-study on bone mineral density. Conducted at 40 clinical centers across the U.S., the study tracked women’s annual visits for an average of 8 years.

Researchers found that those who reported experiencing moderate or severe hot flashes at the start of the study were more likely to sustain a hip fracture during the follow-up period than those who were symptom-free. Moderate to severe menopausal symptoms were also linked to lower bone mass density at the neck and spine during follow-up.

“There may be common links between hot flashes and osteoporosis, such as higher levels of inflammation, or excessive activation of the sympathetic nervous system (the fight-or-flight reaction), but these are only hypotheses that we need to test,” Crandall says.

This research is still in its early stages, because these associations have not been previously reported in a large study of US women followed over many years.  

“While we are figuring out why these links exist, it would be wise for women with hot flashes to pay particular attention to lifestyle behaviors that are beneficial for bone health,” Crandall says. “These include avoiding smoking or excessive alcohol intake, having optimal calcium and vitamin D intake, and getting adequate physical activity.”

Crandall and her colleagues hope to conduct further research to illuminate the connection between bone health and menopausal symptoms. “We will try to study the biological explanations for these findings, which will be critical for us to be able to target the women at the highest risk for preventive measures,” she says.

Colleen Mullarkey


Crandall CJ, Aragaki A, Cauley JA, Manson JE, LeBlanc E, Wallace R, et al. Associations of menopausal vasomotor symptoms with fracture incidence. J Clin Endocrinol Metab. 18 Dec 2014. [Epub ahead of print].