The hormonal hypothesis of RLS revisited – prevalence of RLS in transsexuals

The hypothesis that RLS is associated with altered levels of hormones receives its major support by the well-documented finding that there is a markedly high incidence of RLS in pregnant women. Up to one third of them experience RLS mostly during the last trimester of pregnancy. During pregnancy prolactin, progesterone and estrogens are at high levels peaking during the third trimester. To explore whether high levels of estrogens are associated with RLS we examined the incidence of RLS in transsexual patients who are treated with high doses of either testosterone or estrogens. Questionnaires including the PSQI and the ESS, as well as questions regarding the four cardinal symptoms of RLS were mailed to 288 transsexual patients registered within the last 5 years at the outpatient clinic for endocrinology at the Max Planck Institute of Psychiatry. From the 288 questionnaires mailed 102 could not be delivered and were returned. To date, 77 persons replied (41% of 186). Sixty-nine persons did take estrogens (n=29) or testosterone (n=40). Twenty-four percent (7 of 29) of persons taking estrogens had all four symptoms of RLS, while the corresponding rate was 10% (4 of 40) for persons taking testosterone. Conclusions: These preliminary data point to a high incidence of RLS in transsexual patients who are taking high doses of estrogens. This supports the hypothesis that estrogens may play a role in the pathophysiology of RLS.