NEW ORLEANS — Premenopausal vasomotor symptoms, particularly night sweats, are a previously unrecognized risk factor for low bone mineral density and enhanced bone turnover in infertile women—and probably in fertile women as well, although this has not yet been confirmed, according to Dr. Lubna Pal of the Albert Einstein College of Medicine, New York.
Her study won the prize paper award from the Society for Reproductive Endocrinology and Infertility at the annual meeting of the American Society for Reproductive Medicine.
Based on these data, “I would advise providers to specifically ask about vasomotor symptoms in premenopausal women and, for those who are symptomatic, to focus on unmasking additional factors that may enhance their fracture risk, such as low body mass; family or personal history of fractures; or smoking,” she said in an interview. “I don't think we are there yet in terms of recommending bone density screening for this population … but these women need to be advised that a further deterioration in their bone density parameters is likely to occur in the postmenopausal period, and measures to optimize skeletal health should be addressed now rather than later.”
The cross-sectional study included 86 premenopausal infertile women aged 42 years or younger without premature ovarian failure or oophorectomy. A questionnaire was used to ask about the presence and frequency of vasomotor symptoms, including hot flashes and night sweats. The study also measured subjects' bone mineral density (BMD) and levels of serum N-telopeptide (NTx), a marker of bone turnover.
A total of 12% of respondents reported one or both vasomotor symptoms, and 21% of respondents had evidence of low BMD, Dr. Pal reported at the meeting.
There was a highly significant correlation between vasomotor symptoms and low BMD, with 62.5% of symptomatic women showing evidence of low BMD, compared with 14% of asymptomatic women (odds ratio 10.18). Similarly, 36% of women with low BMD reported vasomotor symptoms, compared with 5% of those with normal BMD.
After controlling for age, body mass index, menstrual regularity, race, and smoking, the study found that vasomotor symptoms (night sweats and/or hot flashes) were independent predictors of low bone density in the study population. The magnitude of this association was most robust for night sweats, with an adjusted odds ratio (AOR) of 52.47, followed by both symptoms combined (AOR 24.10), and then hot flashes alone (AOR 15.10).
The presence of night sweats was also an independent predictor of bone turnover, with higher levels of serum NTx seen in symptomatic compared with asymptomatic women, she said.
And finally, levels of inhibin B, a marker of ovarian reserve, were also significantly lower in women with night sweats compared with asymptomatic women, “suggesting that declining ovarian reserve may be a unifying physiologic mechanism tying vasomotor symptoms to both increased bone turnover and low bone density in this young population,” she said.
“I anticipate that the association between vasomotor symptoms and low bone density in the premenopause will hold true for fertile women, but I have not yet studied this population,” Dr. Pal said.