Research linking estrogen to blood flow indicates there may be a connection between estrogen and the development of Raynaud’s phenomenon. If true, it would explain why the incidence of Raynaud’s among women is significantly (nine times) higher than found among men.
The study titled “G-protein coupled estrogen receptor-mediated non-genomic facilitatory effect of estrogen on cooling-induced reduction of skin blood flow in mice” was conducted by researchers at the University of Shizuoka in Japan. The researchers found that estrogen may be involved in boosting responses to cold and can interact with cell surface receptors to control blood flow through the body. In the study, when mice had higher levels of estrogen circulating through their system, there was an increased sensitivity to cold temperatures and reduced blood flow to their extremities.
The study results are not so straightforward as external cell receptors may be involved. Stimulating one receptor known to interact with estrogen also increased the reduction in blood flow, so it’s still not clear that there’s a direct causal effect between the presence of high levels of estrogen and the development of Raynaud’s, but it may contribute to the condition, and its role certainly deserves further study.
Editors note: We’d heard from a member years back that when she was taken off Premarin following a mild heart attack, her Raynaud’s symptoms became less frequent. She learned that taking unopposed estrogen (i.e., without added progesterone) may contribute to Raynaud’s symptoms. The issue was confirmed in a 1998 study in the New England Journal of Medicine titled “Raynaud’s and Unopposed Estrogen.”