For the randomized study, 227 women with stage I-III breast cancer undergoing chemotherapy at MD Anderson were randomized to one of three groups: a Tibetan yoga program, a simple-stretching program, or a waitlist control group receiving usual care. Participants in the Tibetan yoga program and the stretching program attended four 75-90 minute classes during their chemotherapy treatment.
Participants in the Tibetan yoga program were taught one-on-one by a trained instructor, with each class focusing on controlled breathing, visualization, meditation and postures. Patients were encouraged to practice daily, at home outside of class.
Prior to starting the interventions, participants completed baseline questionnaires and wore an actigraphy watch, which monitors rest and activity cycles, 24 hours a day for seven days to assess sleep quality. Follow-up assessments were conducted one week after the end of intervention and three, six, and 12 months later.
Sleep disturbances and fatigue were assessed using the self-reported Pittsburgh Sleep Quality Index and the Brief Fatigue inventory. Participants also wore actigraphs 24 hours a day for seven days at each study time point to measure sleep.
There were no statistically significant group differences in total sleep disturbances or fatigue levels over time, but participants in the Tibetan yoga group reported fewer daily disturbances one week post-treatment than either of the other groups.
Additionally, long-term sleep benefits emerged over time for those who practiced Tibetan yoga at least two times a week. Compared to those who practiced less often, these patients reported fewer daily disturbances three months post-treatment, as well as better sleep quality and efficiency at six months post-treatment. These patients also reported fewer daily disturbances three months and better sleep efficiency six months relative to the usual care control group.
“Previous research has established that yoga effectively reduces sleep disturbances for cancer patients, but have not included active control groups or long-term follow-up,” said Cohen. “This study hoped to address previous study limitations.”