An eight-week yoga intervention is associated with improvements in pain, psychological functioning and mindfulness, and changes in cortisol levels in women with fibromyalgia

Journal of Pain Research Dovepress open access to scientific and medical research O r i g i n al R e s e arc h Journal of Pain Research downloaded from https://www.dovepress.com/ by 88.198.20.149 on 17-Oct-2019 For personal use only. Open Access Full Text Article An eight-week yoga intervention is associated with improvements in pain, psychological functioning and mindfulness, and changes in cortisol levels in women with fibromyalgia This article was published in the following Dove Press journal: Journal of Pain Research 25 July 2011 Number of times this article has been viewed Kathryn Curtis Anna Osadchuk Joel Katz Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada Objectives: Fibromyalgia (FM) is a chronic condition characterized by widespread musculoskeletal pain, fatigue, depression, and hypocortisolism. To date, published studies have not investigated the effects of yoga on cortisol in FM. This pilot study used a time series design to evaluate pain, psychological variables, mindfulness, and cortisol in women with FM before and after a yoga intervention. Methods: Participants (n = 22) were recruited from the community to participate in a 75 minute yoga class twice weekly for 8 weeks. Questionnaires concerning pain (intensity, unpleasantness, quality, sum of local areas of pain, catastrophizing, acceptance, disability), anxiety, depression, and mindfulness were administered pre-, mid- and post-intervention. Salivary cortisol samples were collected three times a day for each of two days, pre- and post-intervention. Results: Repeated measures analysis of variance (ANOVA) revealed that mean ± standard deviation (SD) scores improved significantly (p , 0.05) from pre- to post-intervention for continuous pain (pre: 5.18 ± 1.72; post: 4.44 ± 2.03), pain catastrophizing (pre: 25.33 ± 14.77; post: 20.40 ± 17.01), pain acceptance (pre: 60.47 ± 23.43; post: 65.50 ± 22.93), and mindfulness (pre: 120.21 ± 21.80; post: 130.63 ± 20.82). Intention-to-treat analysis showed that median AUC for post-intervention cortisol (263.69) was significantly higher (p , 0.05) than median AUC for pre-intervention levels (189.46). Mediation analysis revealed that mid-intervention mindfulness scores significantly (p , 0.05) mediated the relationship between pre- and post-intervention pain catastrophizing scores. Discussion: The results suggest that a yoga intervention may reduce pain and catastrophizing, increase acceptance and mindfulness, and alter total cortisol levels in women with FM. The changes in mindfulness and cortisol levels may provide preliminary evidence for mechanisms of a yoga program for women with FM. Future studies should use an RCT design with a larger sample size. Keywords: fibromyalgia, pain, cortisol, yoga, psychological variables Introduction Correspondence: Katy Curtis Department of Psychology, BSB 297, York University 4700 Keele Street, Toronto, ON M3J 1P3 Canada Tel +1 647 995 5289 Fax +1 416 736 5814 Email or submit your manuscript | www.dovepress.com Dovepress http://dx.doi.org/10.2147/JPR.S22761 Powered by TCPDF (www.tcpdf.org) Fibromyalgia (FM) is a poorly understood condition that is characterized by widespread musculoskeletal pain and presents with other symptoms such as fatigue, cognitive dysfunction, sleep disturbances, anxiety, depression, gastrointestinal discomfort and stiffness.1 Recent proposed changes to the American College of Rheumatology (ACR) formal diagnostic criteria for FM include implementation of the widespread pain index (WPI) and symptom severity scale (SS), to supplement the previous gold standard of Journal of Pain Research 2011:4 189–201 189 © 2011 Curtis et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. Journal of Pain Research downloaded from https://www.dovepress.com/ by 88.198.20.149 on 17-Oct-2019 For personal use only. Curtis et al a tender point count, along with widespread pain for at least 3 months in at least 3 of the 4 quadrants of the body.2 Female gender, older age, low level of education, low socio-economic status, and divorce have been associated with FM.3 Psychological distress is a major risk factor for long term complaints4 and comorbidity with anxiety and depression is high,3 with rates of 13%–64% and 20%–80%, respectively.5 Moreover, FM patients display generalized hypervigilance,6 characterized by a greater sensitivity to external stimuli in various modalities. Pain catastrophizing and low pain-self efficacy are other psychological factors that prevent healthy adjustment to FM7 and contribute to disability,8 pain, depression and quality of well being.9 Although the neurophysiological underpinnings of this disorder have yet to be elucidated, there is evidence that central sensitization is largely implicated in the extensive and enduring pain and that FM is accompanied by altered hypothalamic pituitary adrenal (HPA) axis and autonomic nervous system (ANS) functioning.3 Cortisol is a steroid hormone that is produced and released by the adrenal gland, and functions as a component of the hypothalamic-pituitary-adrenal (HPA) axis in response to stress or low blood sugar. Healthy HPA axis functioning, as measured by cortisol secretion, entails higher cortisol levels upon waking, a peak approximately 30–40 minutes postwaking (the cortisol awakening response [CAR]) and a decline over the course of the day, when levels reach a trough prior to sleep onset.10 Healthy functioning also involves HPA resilience, which refers to the ability of the HPA system to recover or rebound from stress. The literature on HPA functioning and cortisol levels in FM patients is equivocal.11 A host of variables complicates an accurate portrayal of HPA function, but variations in the methods used to collect cortisol samples, such as time of cortisol measurement (morning, afternoon, evening), number of measurements per day (1–8, or continuous readings), and source (salivary, plasma, serum or urinary) of cortisol, make it particularly difficult to derive a clear picture of HPA activity in FM patients.12 Notwithstanding the variability in cortisol sampling procedures and findings, it is accepted that there is a dysregulation of HPA functioning in patients with FM,11 resulting in alterations in levels of cortisol, corticotropin-releasing hormone, growth hormone and thyroid hormones, which may have secondary effects on pain, fatigue, immune function, mood and sleep.3 Recent research indicates that FM patients exhibit hypocortisolism, particularly as an attenuated CAR.13 Hypocortisolism is characterized by a blunted presentation of cortisol secretion, compromised HPA resilience and a triad 190 Powered by TCPDF (www.tcpdf.org) submit your manuscript | www.dovepress.com Dovepress Dovepress of pain, fatigue and stress sensitivity.14 In support of this idea, women with FM have lower urina (...truncated)