Research Article Effect of Yoga on Pain, Brain-Derived Neurotrophic Factor, and Serotonin in Premenopausal Women with Chronic Low Back Pain
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Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2014, Article ID 203173, 7 pages http://dx.doi.org/10.1155/2014/203173 Research Article Effect of Yoga on Pain, Brain-Derived Neurotrophic Factor, and Serotonin in Premenopausal Women with Chronic Low Back Pain Moseon Lee,1 Woongjoon Moon,2 and Jaehee Kim1 1 Graduate School of Alternative Medicine, Kyonggi University, 24 Kyonggidae-ro 9-gil, Seodaemun-gu, Seoul 120-702, Republic of Korea 2 Division of General Studies, Seoil University, Yongmasan-ro 90-gil, Jungnang-gu, Seoul 131-702, Republic of Korea Correspondence should be addressed to Jaehee Kim; [email protected] Received 28 February 2014; Revised 24 June 2014; Accepted 26 June 2014; Published 10 July 2014 Academic Editor: Ke Ren Copyright © 2014 Moseon Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Serotonin and brain-derived neurotrophic factor (BDNF) are known to be modulators of nociception. However, pain- related connection between yoga and those neuromodulators has not been investigated. Therefore, we aimed to evaluate the effect of yoga on pain, BDNF, and serotonin. Methods. Premenopausal women with chronic low back pain practiced yoga three times a week for 12 weeks. At baseline and after 12 weeks, back pain intensity was measured using visual analogue scale (VAS), and serum BDNF and serotonin levels were evaluated. Additionally, back flexibility and level of depression were assessed. Results.After12- week yoga, VAS decreased in the yoga group ( < 0.001), whereas it increased ( < 0.05) in the control group. Back flexibility was improved in the yoga group ( < 0.01). Serum BDNF increased in the yoga group ( < 0.01), whereas it tended to decrease in the control group ( = 0.05). Serum serotonin maintained in the yoga group, while it reduced ( < 0.01) in the control group. The depression level maintained in the yoga group, whereas it tended to increase in the control group( = 0.07). Conclusions.We propose that BDNF may be one of the key factors mediating beneficial effects of yoga on chronic low back pain. 1. Introduction Yoga, one of the most popular mind-body interventions, has been known to improve back pain and functional The most recent systematic review of the global prevalence oflowbackpaininadultsshowedthe1-monthprevalence disability in patients with chronic low back pain [12, 13]. of 23% [1], suggesting that low back pain is a global health It is typically considered that yoga is comprised of phys- problem. Indeed, it has been reported that prevalence of ical postures (asanas), breathing techniques (pranayama), chronic low back pain ranges from 10 to 20% and recently and meditation (dhyana) [14]. Recently, it is suggested that increases [1, 2]. Approximately 90% of low back pain is improvement of physical function and modulation in pain nonspecific, defined as pain symptoms with no specific causes perception pathway may act synergistically [6, 15]although [3]. Overall, most of patients with back pain recover by 4– the underlying mechanisms of the effect of yoga on chronic 12 weeks and the pain tends to become chronic after 12 low back pain still remain unclear [12]. weeks [4, 5]. Chronic low back pain is recognized to have Serotonin (5-hydroxytryptamine [5-HT]) has been rela- multifactorial etiology including mechanical, psychological, tivelywellknowntobeassociatedwithnociceptionmodu- and neurological factors [6]. Therefore, multidisciplinary lating the endogenous analgesic system [16]. Antidepressants treatment approaches seem to be needed [6]. Nonpharma- have been treated for pain relief and reported to have cological therapies such as exercise, acupuncture, massage, antinociceptive effect partly mediated by the serotonergic spinal manipulation, and yoga have been recommended and systems [17, 18]. Recently, antidepressant treatment has been showntobemoderatelyeffectivefortreatingchroniclow reported to reduce pain in nondepressed patients with non- back pain [7–12]. neuropathic chronic low back pain [19]. 2 Evidence-Based Complementary and Alternative Medicine Brain-derived neurotrophic factor (BDNF) which plays gave their written informed consent before participating in important roles in neuroplasticity of central nervous system study. is now known to regulate sensory neurotransmission at spinal and brain levels and to modulate neuropathic and inflamma- 2.2. Subjects. The inclusion criteria were as follows: pre- tory pain in adulthood [20–22]. Over the past decade, animal menopausal women; low back pain lasting more than 3 and human studies have been shown that BDNF is expressed 2 months;nonobese(BMI< 25 kg/m ); no radiating pain; no in nondegenerate and degenerate intervertebral discs and spine surgery; no use of pain medication; and currently herniated disc implicating that BDNF may be associated with no regular exercise or other therapy for back pain. Exclu- low back pain [23–26]. sion criteria included pregnancy, inflammatory disease (e.g., BDNF and serotonin increase with exercise intervention rheumatoid arthritis), infectious disease, spine disorders, and are regarded as mediating beneficial effects of exercise osteoporosis, cancer, cardiovascular disease, or neurological on mental and neurological disorders [20]. Although con- disease. siderable evidences that exercise increases BDNF levels in various disease states have been accumulated [20, 27–29], the detection of changes in BDNF levels as an effector of 2.3. Yoga Program. The 12-week Hatha yoga program was exercise on pain modulation has not been reported [29]. performed for 1 hour, three times a week in a yoga studio. Interestingly, one recent study reported that serum BDNF One experienced yoga instructor taught all yoga classes. increased with 12-week yoga in depression patients [30]. The instructor has a long-term experience in teaching yoga Moreover, serotonin has been proposed as one of neuromod- therapy to individuals with low back pain. Yoga program ulators mediating the effect of yoga [31, 32]. Given previous consistedofasetof10-minutewarm-up(breathingand findings, we hypothesized that yoga could change BDNF and stretching), 40-minute yoga poses with appropriate aware- serotonin levels and changes in those neuromodulators of ness of breathing, and 10-minute relaxation and meditation. pain could be concomitant with improvements in pain and TheHathayogaposesusedinthisstudywereadaptedfrom physical function in patients with chronic low back pain. previous studies [13, 35]. The yoga program was divided into three 4-week segments. Twelve poses were selected To the best of our knowledge, the effect of yoga on any from 24 postures for each segment. Subjects were gradually pain modulator including BDNF and serotonin in patients progressed from simple poses to more challenging poses with low back pain has not yet been investigated. Accordingly, with each subsequent segment. No props were used. Some in this study we investigated effects of 12-week yoga interven- yoga poses were modified for people with low back pain. tion on pain, back flexibility, depression, and serum BDNF Participants were recommended to decrease the range of and serotonin levels in premenopausal women with chronic motion or fold their knees not to go over their physical limits. low back pain. Plow pose and shoulder-stand pose were replaced with bridge pose when they had difficulties. Each segment included the 2. Methods following poses: 2.1. Study Design. Forty-three premenopausal women with (1) weeks 1–4: seated forward bend (Paschimottanasana), chronic low back pain were recruited with a local flyer in half-spinal twist pose (Ardha Matsyendrasana), cow the Dongtan city in Gyeonggi-do and Seoul city, Republic face pose (Gomukhasana), cobra pose (Bhujan- of Korea. Twenty-three women in an experimental group gasana), heron pose (Krauncasana), fish pose (Mat- underwent a 12-week group-based yoga program. Twenty syasana), tree pose (Vrksasana), cat and cow pose women in a control group who were matched to the exper- (Marjariasana), locust pose (Salabhasana), standing imental group by age and body mass index (BMI) were forward bend (Uttanasana), triangle pose (Utthita untreated.AgeandBMIwerematchedintwogroupssince Trikonasana), and butterfly pose (Baddha Konasana); serum level of BDNF is age- and weight-dependent [33]. In addition, because benefits of exercise on BDNF were reported (2) weeks 5–8: tree pose (Vrksasana), cat and cow pose to depend on the presence of estrogen [34], we have excluded (Marjariasana), locust pose (Salabhasana), standing postmenopausal women from the study. forward bend (Uttanasana), triangle pose (Utthita At baseline and after 12 weeks, back pain intensity, back Trikonasana), butterfly pose (Baddha Konasana), flexibility, depression, and serum BDNF and serotonin levels half-moon pose (Ardha Chandrasana), bridge pose were measured in both groups. Data from subjects who did (Setu Bandhasana), bow pose (Dhanurasana), knee not complete less than 70% of yoga sessions and dropped out together twist (Jathara Parivartanasana), downward- due to personal reasons were excluded from data analysis. facing dog (Adho Mukha Svanasana), and plow pose Finally, data from fourteen women in the yoga group and (Halasana); eleven women in the control group were analyzed. Attrition (3) weeks 9–12: half-moon pose (Ardha Chandrasana), rate in the yoga