Kiecolt-Glaser, J.K., Bennett, J.M., Andridge, R., Peng, J., Shapiro, C.L., Malarkey, W.B., . . . Glaser, R. (2014). Yoga’s impact on inflammation, mood, and fatigue in breast cancer survivors: A randomized controlled trial. Journal of Clinical Oncology. Advance online publication.
To assess the effects of yoga on inflammation, mood, and fatigue and to test the hypothesis that yoga would decrease inflammation, depressive symptoms, and fatigue in breast cancer survivors
Women were randomly assigned to the intervention group or a wait-list control group. The intervention consisted of two 90-minute Hatha yoga sessions per week for 12 weeks delivered in a group setting. Sessions were audiotaped, and 50% were randomly assessed for differences from predetermined poses to assess fidelity of the intervention. Yoga teachers called anyone who missed a class. Home practice was encouraged, and all practice times were recorded by participants in weekly logs. Data were collected at baseline, immediately after the intervention, and after three months post-treatment.
Single-blinded, randomized, controlled trial
Patients attended a median of 79% of yoga classes and reported an average of 24.69 minutes of practice per day at home and in class over 12 weeks. Immediately after the intervention, there were no differences between the groups in fatigue; however, in the yoga group, fatigue was significantly lower at three months (Cohen’s d = -0.36, p = 0.002). Vitality in the yoga group was significantly higher immediately post-treatment and at three months (p = 0.01). There were no differences between the groups in depressive symptoms. Immediately postintervention, there were no differences between groups in cytokine levels; however, at three months, the yoga group had significantly lower cytokine levels compared to the control group (p < 0.05). Yoga participants reported improved sleep compared to patients in the control group (p = 0.03).
Yoga was associated with reduced fatigue, increased vitality, improved sleep, and reduced cytokine levels. Yoga did not appear to have an effect on depressive symptoms in this study.
The findings of this study demonstrated that yoga practice was effective in reducing fatigue and improving vitality and sleep in this patient population. Nurses can suggest that patients become involved in yoga practice as a way to manage fatigue and sleep disturbance. These findings also suggest that yoga can have an impact on subclinical inflammation, which may be a mechanism that fuels fatigue and the decline of physical function.