Study: Obesity's impact on incidence of hot flashes may depend on age

A recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM) found that among women aged 60 and above, heavier women have fewer hot flashes than their leaner counterparts. The inverse association between body size and hot flashes was observed only among the older women.

In the last decade, research on perimenopausal women has shown that heavier women tend to have more hot flashes. As a result of this research, clinicians began to observe obesity as a risk factor for hot flashes. However, according to this new study, after a woman reaches an age where she becomes menopausal and her ovary no longer produces estrogen, it appears that the heavier the woman is, the fewer hot flashes she experiences.

"This study provides a more nuanced understanding of the relationship between body size and hot flashes, emphasizing the important role of age," said the study's lead author, Rebecca Thurston, PhD of the University of Pittsburgh. "Our findings show that the benefit of higher fat levels for hot flashes is not apparent until a woman is about 60 years old."

In this study, researchers examined 52 women who had reported hot flashes and were not on medication impacting hot flashes. Study participants had their body fat percentage, waist circumference and BMI measured and were physiologically assessed for hot flashes by use of a monitor that measured skin conductance. Participants also self-reported hot flashes by using a portable electronic diary.

"Our study showed that higher adiposity, BMI and waist circumference were associated with fewer physiologically-assessed hot flashes among older postmenopausal women with hot flashes," said Thurston.

"Moreover, associations were most pronounced among Caucasian women. This study underscores the importance of considering how age and race may modify the relationship between obesity and hot flashes."