Qigong, Parasympathetic Function and Fibromyalgia

Fibromyalgia (FM) is characterized by widespread pain and multiple other symptoms; underlying mechanisms include central sensitization, dysregulation of the stress response system, and autonomic nervous system dysregulation. Alterations in the sympathetic nervous system have been variably implicated, but a reduction in parasympathetic nervous system (PNS) activity is now becoming more clearly implicated. Qigong, a traditional health and wellness practice that is also considered as mindful exercise or meditative movement, has been shown in several controlled and uncontrolled trials to be of marked benefit in FM, with effects that are sustained over time. Several hypotheses have been considered to account for the benefits of qigong practice, including autonomic regulation. The current article proposes that qigong, as a self-practice, leads to enhanced PNS activity, and this underlies benefits in FM and contributes to other health benefits that occur with extended practice. This hypothesis could be tested: (a) by exploring benefits of non-invasive vagal nerve stimulation (this should mimic effects of qigong), (b) by demonstrating that qigong practice produces changes in PNS activity, (c) by demonstrating that other non-pharmacological therapies that have been shown to be of benefit in FM also modulate PNS activity. The hypothesis is amenable to direct testing. Fibromyalgia and the Autonomic Nervous System Fibromyalgia (FM) is a chronic condition involving widespread pain, fatigue and multiple other symptoms, all of which contribute to a diminished quality of life [1,2]. FM is also known as a syndrome, reflecting the prominent involvement of other symptoms in addition to pain. FM was recognized as a clinical entity in the early 1990s with the American College of Rheumatology proposal of classification criteria; these criteria were modified in 2010 [3,4]. There is overlap between FM and several related conditions (e.g. chronic fatigue syndrome or CFS, irritable bowel syndrome or IBS, headache disorders), and a unifying concept has been to consider these as central sensitivity syndromes or CSSs [5-7]. FM is also prevalent in other chronic pain conditions [8]. Mechanisms contributing to FM include: 1) sensitization in central pain pathways, with amplification in pain transmitting mechanisms, reduction in inhibitory pain modulation, and neurotransmitter, neurotrophic and neuroplastic changes; 2) dysregulation of the hypothalamic-pituitary-adrenal axis and the stress response system; 3) genetic factors; 4) psychological and traumatic factors [1,2,9-12]. Autonomic nervous system dysfunction in FM and related conditions (CFS, IBS) was first proposed in the 1990s [13,14], and subsequent studies have continued to provide support for such dysfunction. The autonomic nervous system is a complex adaptive system that regulates vital functions (e.g. blood pressure, heart rate, respiration) and maintains homeostasis; it includes the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS), and these two systems have opposite effects on many bodily functions. The term “autonomic” indicates that the system is not consciously governed, and regulation occurs via multiple feedback mechanisms. More recent reviews of studies assessing SNS function (using heart rate variability (HRV) spectral analysis, sympathetic skin responses, tilt table testing, and other methods) indicate that SNS predominance, together with blunted responses to stressors, is common in FM and CFS [15,16]. With CFS, increased sympathetic activity occurs during the night [15]. On the other hand, reduction in PNS activity, as reflected in decreased high-frequency heart rate variability, also is prominently implicated in FM and is receiving increasing attention [17]. It has been speculated that alterations in the complex adaptive system that the autonomic nervous system represents provides a nonreductionistic and non-linear framework for considering the etiology of FM and explaining diverse symptomology that may not necessarily be explained just by considering central sensitivity [18-20]. In nonlinear systems, there is a complex and dynamic relationship between factors, such that cause and effect are not readily discerned. Qigong and Fibromyalgia Qigong has a long history in China, and many forms have been elaborated in distinct domains (health maintenance, medical qigong, martial qigong, spiritual qigong) [21,22]. The scientific study of medical qigong began in the 1950s, and has increased dramatically over recent decades. Qi means “vital energy” or “life-force energy” and gong means “skill”, and the practice of qigong represents cultivation of a domain of function. Internal qigong refers to self-practice, while external qigong refers to a projected skill delivered by a master proficient in the practice. The core elements of qigong involve movement, breath and mental practices, and it is traditionally regarded as a self-healing mind-body practice. Contemporary terminology for qigong is “mindful exercise” [23] or “meditative movement” [24,25], and such characterizations are helpful for deconstruction, operationization, and considering mechanisms involved. The main focus of considerations in the current article relate to internal qigong as self-practice. Several studies have examined effects of different forms of qigong in FM. When qigong is practiced regularly (30 mins, ≥ 5 days a week, 6-8 weeks), there are consistent improvements in pain, sleep, impact, and Fibromyalgia: Open Access Sawynok J, Fibrom Open Access 2016, 1:2 Review Article Open Access Fibrom Open Access ISSN: Fibrom Open Access Volume 1 • Issue 2 • 1000107 mental and physical function following the practice, and benefits are maintained at 3-6 months follow-up [26-29]. The magnitude of effects is notable, with effect sizes (standard mean differences) of 0.5-1.0 and greater observed over several domains, and these are generally maintained at follow-up [30]. Some earlier qigong studies involved weekly sessions of qigong, but practice requirements in between were not required or not stringent and ambiguous effects were reported [31-33]. There is direct quantitative data indicating that benefit is related to amount of practice, as those who practiced per protocol had more favorable outcomes in all measures compared to those who practiced minimally [28]. This difference in outcomes between practice groups was also manifest in qualitative comments on experiences with the practice [34]. There are several recent systematic reviews and metaanalyses of qigong for FM, either alone [35,36] or along with Tai Chi and yoga [37,38]; these are cautious in their conclusions regarding qigong because not all consider the full range of studies that are available, and even when this has occurred, trials were considered as a cohort without stratification for amount of practice. In addition to randomized controlled trials in which qigong was practiced for a standard regimen, there have also been uncontrolled reports of effects of extended practice of qigong in FM subjects. Thus, there is an extension trial involving qigong practice for at least 1 year [39], and case studies of qigong practiced over even more extended periods (1-3 years) in a community setting [40]. These reports document marked benefits in core FM symptoms (pain, sleep, impact, mental and physical function) as well as other health benefits (e.g. improvement in asthma, sleep apnea, food and chemical tolerance, headaches) as reflected in qualitative comments [30,39,40]. It is important to note that those who undertake extended practice experience initial benefits with the therapeutic regimen, and these benefits motivate the extended practice. Similar initial benefits occurred in those undertaking community-based practice and were a prominent motivator for continued practice [40]. [There is also a report of marked improvements in FM with external qigong with benefits maintained at follow-up 3 months later [41]. However, mechanisms involved in external qigong, by definition, differ from those involved in internal qigong which is the main focus of the current review.] There are now several reports that qigong self-practice is also of benefit in CFS, another condition regarded as a CSS and exhibiting autonomic dysfunction (section 1). These studies involved two different qigong regimens of instruction, and regular practice over 2-4 months; qigong practice resulted in significant improvements in sleep, fatigue and signs of anxiety and depression following the intervention, and at follow-up at 3 months [42-44]. Furthermore, the amount of practice was significantly associated with improvements in sleep, fatigue, anxiety and depression [44]. [There are also case reports of external qigong providing marked benefit in CFS [45].] An emerging body of information indicates qigong is useful for fatigue, anxiety and depression in a range of conditions [25,46,47]. However, there has been limited consideration of the relationship of amount of practice to outcomes in these studies.