The study also found that women taking Cenestin experienced an improvement in sleep latency and total sleep time, falling asleep faster and sleeping for a longer period of time.

"When estrogen levels in a woman's body decrease, their difficulties with sleep increase," said Dr. Scharf, whose data was presented at the 15th Annual Meeting of the North American Menopause Society in Washington, D.C. "Not only does the menopausal woman have to deal with symptoms like hot flashes, but she also has to manage potential increased irritability, depression and loss of well-being resulting from poor sleep."

Menopausal Sleep Disturbances Common

"This pilot study is encouraging because it showed that when menopausal women took an estrogen therapy like Cenestin, the number of night sweats and hot flashes they experienced was reduced and they seemed to sleep better," said Dr. Scharf.

More than 1.5 million women each year enter menopause in the United States alone. Sleep disruptions are common among menopausal women, with more than one third of menopausal/post-menopausal women reporting nocturnal hot flashes as a reason for sleep difficulty.

Dr. Scharf's pilot study examined the effect of Cenestin on sleep in post-menopausal women experiencing nocturnal diaphoresis (excessive sweating) and hot flashes. Dr. Scharf explained that Cenestin was chosen for the study since it is derived from plant sources; he felt that women may be more comfortable taking a plant-derived conjugated estrogen that is indicated for the treatment of moderate-to-severe vasomotor symptoms (hot flashes and night sweats) and vulvar and vaginal atrophy (vaginal itching and dryness) associated with menopause.

The pilot study enrolled 19 post-menopausal females between 45 and 60 years of age who experienced an average of two incidences of night sweats and/or hot flashes per night. The women, who were post-menopausal for at least six months -- or two months if menopause was induced by the surgical removal of the uterus -- received a baseline screening including a physical exam, medical and sleep history, and completed a two-week diary reporting sleep quality, sleepiness and hot flashes.

79% Reduction in Hot Flashes

After a baseline of three nights taking placebo, participants were randomized to either 0.625 mg of Cenestin (n=9) or placebo (n=10) once daily for a six-week period. They were monitored at a sleep center at the start of the trial, and again during the final three days of treatment, using standard monitoring methods to track sleep stages, eye movement, total sleep time, wake time and the number of times they awoke during the night. Galvanic skin responses -- an electrical skin conductance from the palms, face or scalp -- measured sweat gland activity.

Results showed a 79% reduction in the number of hot flashes in the Cenestin group. The mean reduction in galvanic skin responses was also significant, with a 57 percent reduction for the group that received Cenestin.

It was noted that patients taking Cenestin had a noticeable clinically significant difference in several sleep monitoring methods, suggesting an improvement in overall sleep quality and supportive of previous conclusions showing the efficacy of hormone therapy in improving sleep efficiency and wakenings.