Many women in the menopausal transition experience hot flashes: unpredictable, sometimes disruptive, periods of intense heat in the upper torso, neck and face. Although generations of physicians have prescribed hormones to reduce these symptoms, very little research has focused on the underlying causes of hot flashes.
Three new studies explore the role of genes, obesity and alcohol consumption in contributing to or lessening the intensity and frequency of hot flashes in midlife women. These studies are part of a five-year research effort led by University of Illinois veterinary biosciences professor Jodi Flaws and colleagues at the University of Maryland, Mercy Medical Center in Baltimore and the School of Medicine at Johns Hopkins University.
Physicians have long noted that some factors, such as smoking, increase the likelihood that a woman will experience more or more intense hot flashes than other women. Race also appears to play a role, with African American women at higher risk than others. But the mechanisms that cause some women to suffer from severe (frequent and intense) hot flashes have remained a mystery.
"Even though more than 40 million women experience hot flashes each year," the authors wrote in their paper published in Maturitas, "little is known about the factors that predispose women to hot flashes."
To examine whether genetics might play a role in hot flashes, Flaws and her colleagues conducted a cross-sectional study involving 639 women aged 45 to 54. The researchers looked at individual differences in the genes that code for various hormones. An earlier study by the same team had found that one of these genetic polymorphisms, in an estrogen metabolizing enzyme, cytochrome P450 1B1, was more common in women who reported higher-than-average frequency, intensity and duration of hot flashes.
The new study tied the same genetic polymorphism to lower levels of an androgen known as DHEA-S, and to
Contact: Diana Yates
University of Illinois at Urbana-Champaign