Between 30 percent and 90 percent of cancer survivors experience some degree of sleep quality disturbance after treatment, and these sleep problems may last for months or even years.
For the study, participants who attended 75-minute yoga sessions twice a week for a month were able to cut back on using their sleep medications by 21 percent, compared with patients in standard care, who actually increased their use of these medications by 5 percent per week.
Both groups showed noticeable improvements in sleep quality; however, the yoga group showed significant improvements in sleep latency (amount of time it takes to fall asleep), sleep duration, sleep efficiency, sleep disturbances, subjective sleep quality and daytime dysfunction during the intervention period.
“Despite the ubiquity of impaired sleep and its negative consequences, sleep problems are both underdiagnosed and undertreated in post-treatment cancer survivors,” the researchers said.
The yoga program, developed specifically for former cancer patients, included elements of Hatha yoga and restorative yoga, stressing mindful breathing, meditation and gentle stretching.
Patients in the standard care group received follow-up treatment provided by their oncologist as appropriate for the individual diagnosis. Participants in the control condition were also offered the four-week yoga program for free after completing all study requirements.
The study involved a total of 410 cancer survivors with moderate to severe sleep disturbance issues occurring two to 24 months after primary treatment. Nearly all (96 percent) the patients were women, 75 percent had been treated for breast cancer, and their median age was 54.
All the participants received standard post-treatment care, but half also attended the twice-a-week, 75-minute yoga sessions for four weeks, delivered in community-based sites, which included yoga centers, community centers and community oncology centers.
Sleep quality was evaluated at the beginning of the study using the Pittsburgh Sleep Quality Index (PSQI). Participants in both groups had average baseline global sleep quality scores of 9.0 on the PSQI, which indicated clinically recognized sleep disturbance.
Participants in the yoga group showed statistically significant improvements in sleep quality between the pre- and post-intervention period; the control group did not.
Furthermore, 90 percent of the yoga intervention group who completed the study said they found the program helpful for improving sleep quality, and 63 percent said they would highly recommend it to other cancer survivors.
Research limitations included a large number of study dropouts, with fully evaluable data unavailable for 22 percent of the participants. The researchers noted that most patients withdrew from the study for reasons unrelated to the yoga intervention.
Furthermore, the study population was homogeneous, including mostly female breast cancer survivors who were white (93 percent), married (72 percent) and had some college education (82 percent). Only 24 (6 percent) of the study participants were African-American and just eight of these were a part of the yoga intervention group.
“These were the people who volunteered for the study,” said Karen Mustian, Ph.D., M.P.H., of the University of Rochester Medical Center (URMC) in Rochester, N.Y., adding that innovative strategies may be needed to interest men and nonwhite female cancer survivors in yoga programs.
Mustian added that that not all styles of yoga may be suitable for cancer survivors. Highly aerobic forms of yoga, and some hybrid versions including “hot yoga” and “spin yoga” may not be appropriate.
“We really can’t speak to the safety of these more vigorous yoga practices,” she said. “The message to patients is to look for a well-qualified instructor who is teaching gentle Hatha yoga or restorative yoga.”
Source: Journal of Clinical Oncology