title: Examining Mediators and Moderators of Yoga for Women With Breast Cancer Undergoing Radiotherapy.
abstract: Hypothesis This study examines moderators and mediators of a yoga intervention targeting quality-of-life (QOL) outcomes in women with breast cancer receiving radiotherapy.Methods Women undergoing 6 weeks of radiotherapy were randomized to a yoga (YG; n = 53) or stretching (ST; n = 56) intervention or a waitlist control group (WL; n = 54). Depressive symptoms and sleep disturbances were measured at baseline. Mediator (posttraumatic stress symptoms, benefit finding, and cortisol slope) and outcome (36-item Short Form [SF]-36 mental and physical component scales [MCS and PCS]) variables were assessed at baseline, end-of-treatment, and 1-, 3-, and 6-months posttreatment. Results Baseline depressive symptoms (P = .03) and sleep disturbances (P < .01) moderated the Group × Time effect on MCS, but not PCS. Women with high baseline depressive symptoms in YG reported marginally higher 3-month MCS than their counterparts in WL (P = .11). Women with high baseline sleep disturbances in YG reported higher 3-months MCS than their counterparts in WL (P < .01) and higher 6-month MCS than their counterparts in ST (P = .01). YG led to greater benefit finding than ST and WL across the follow-up (P = .01). Three-month benefit finding partially mediated the effect of YG on 6-month PCS. Posttraumatic stress symptoms and cortisol slope did not mediate treatment effect on QOL. Conclusion Yoga may provide the greatest mental-health-related QOL benefits for those experiencing pre-radiotherapy sleep disturbance and depressive symptoms. Yoga may improve physical-health-related QOL by increasing ability to find benefit in the cancer experience.
authors: Center for Innovations in Quality, Effectiveness and Safety, Michael E. DeBakey VA Medical Center, Houston, TX, USA Baylor College of Medicine, Houston, TX, USA VA South Central Mental Illness Research, Education, and Clinical Center, Houston, TX, USA.
authors: Chelsea G
authors: CG
authors: Ratcliff
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Kathrin
authors: K
authors: Milbury
authors: University of Rochester Medical School, Rochester, NY, USA.
authors: Kavita D
authors: KD
authors: Chandwani
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Alejandro
authors: A
authors: Chaoul
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: George
authors: G
authors: Perkins
authors: Swami Vivekananda Yoga Anusandhana Samsthana, Bengaluru, India.
authors: Raghuram
authors: R
authors: Nagarathna
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Robin
authors: R
authors: Haddad
authors: Swami Vivekananda Yoga Anusandhana Samsthana, Bengaluru, India.
authors: Hongasandra Ramarao
authors: HR
authors: Nagendra
authors: Swami Vivekananda Yoga Anusandhana Samsthana, Bengaluru, India.
authors: N V
authors: NV
authors: Raghuram
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Amy
authors: A
authors: Spelman
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Banu
authors: B
authors: Arun
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Qi
authors: Q
authors: Wei
authors: The University of Texas MD Anderson Cancer Center, Houston, TX, USA lcohen@mdanderson.org.
authors: Lorenzo
authors: L
authors: Cohen
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000523:psychology* / Q000532:radiotherapy*; D003863:Depression / Q000378:metabolism / Q000523:psychology; D005221:Fatigue / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D019122:Meditation / Q000523:psychology*; D008875:Middle Aged; D011788:Quality of Life; D012893:Sleep Wake Disorders / Q000378:metabolism / Q000523:psychology; D015013:Yoga / Q000523:psychology*
chemical_list: D006854:Hydrocortisone
keywords: QOL; breast cancer; mediation; moderation; yoga