Stress Reduction (Part 2)
Interventions in Diabetes
In part 1 I briefly discussed the role of chronic psychological stress in health and disease, and its specific relevance in diabetes and heart disease. In this month’s article, I will review some of the clinical research evidence that exists for various stress reduction approaches, and how each might impact risk factors in diabetes. Next month, I will review the research for stress reduction in high blood pressure, or hypertension.
...there are two goals for stress reduction: reduction of stressors and improvement of our response.
As mentioned in last month’s article, there are two goals for stress reduction: reduction of stressors and improvement of our response. A critical first step is the internal evaluation of which stressors are real versus perceived? Which stressors do you have control over now vs. which to accept for now? What resources do you have available- personal and in the community- to help? What obstacles to you need to overcome- or reduce- the stressors in your life? After this critical internal appraisal, experimenting with stress reduction techniques that fit into your lifestyle, philosophy and fitness level (in the case of movement therapies) adds an additional resource to your stress reduction toolbox!
Improving response to stress can come from a variety of approaches- including counseling therapies and breathing exercises with and without a movement component. Once learned, stress reduction techniques belong to us for life- whether a meditative therapy or a movement therapy! Nearly all techniques lend themselves to home practice, and can be practiced alone or in a group settings depending on your preference.Techniques for stress reduction without a full-body movement component that have been studied in diabetes include stress management training, biofeedback training, and progressive muscle relaxation. Techniques that also include a movement component include yoga, Tai Chi and Qigong. Many of these practices have become popular and classes are readily available at local gyms, sports clubs, community centers and YMCA facilities.
Once learned, stress reduction techniques belong to us for life...
What does the research say about stress reduction in diabetes?
Progressive muscle relaxation is a technique of systematically flexing/contracting and then relaxing your muscles, starting at your toes and feet and working your way up all the way to your eyes and scalp!
Two of the earliest clinical trials of stress reduction interventions in type 2 diabetes were performed by Jablon et al. and Surwit et al. in 1997 and 2002 respectively. Jablon et al. evaluated progressive muscle relaxation and biofeedback training in 20 adults with type 2 diabetes. 1 Although no improvement was noted in blood glucose in their study, participants did experience reduced stress and anxiety scores following the intervention. (Progressive muscle relaxation is a technique of systematically flexing/contracting and then relaxing your muscles, starting at your toes and feet and working your way up all the way to your eyes and scalp! A typical practice would involve lying down, and beginning by curling your toes, flex and hold the contraction 10 seconds, then fully relax your toes. Move up to your lower legs- contracting for 10 seconds, and then relaxing, and so on. The process continues until you wrinkle up your face and forehead! This technique is excellent for reducing muscular “holding” of stress and is a great practice before sleep!)
Further early clinical trial research was performed by Surwit et al. in 2002 in which they randomly assigned patients to group diabetes sessions with and without stress management training. After 1 year, the group that received stress management training had HbA1c levels 0.5% lower than those who did not receive the stress management training, suggesting the therapies were effective, and the results were persistent.2
Specific Therapies - Tai Chi
One of the most studied stress reduction therapies in type 2 diabetes is Tai Chi, a movement based therapy originating in China.
One of the most studied stress reduction therapies in type 2 diabetes is Tai Chi, a movement based therapy originating in China. Tai Chi was technically a martial art (like karate) but without the punching and kicking. Instead, Tai Chi focuses on long, fluid, flowing movements linked together with breathing exercises into sequences of movements, called forms. Tai Chi is claimed to increase the flow of “Chi”, or “Qi”, (literally breath) the purported energetic vital force within us all!
Tai Chi has been evaluated in at least six clinical trials in type 2 diabetes, producing highly variable findings. Early uncontrolled clinical studies suggested modest improvements in fasting blood sugar and increases in insulin sensitivity 3, however clinical trials that were exercise-controlled for longer duration (16 weeks vs. 8 weeks) failed to show any improvement in insulin sensitivity or HbA1c. 4, 5 In these two neutral studies, Tai Chi was practiced twice a week for sixteen weeks.
Apparently this intensity or duration of practice was not enough to improve metabolic function (and thus did not reduce blood sugar) as subsequent clinical trials of more intensive Tai Chi practice of either increased frequency or longer duration have suggested benefit. Zhang et al. conducted a clinical trial of Tai Chi practiced one hour per day, five days per week for over three months and demonstrated significant reductions in fasting blood sugar, increased insulin and lower triglyceride levels. 6 An additional recent study of Tai Chi practiced twice per week for six months also showed reduced HbA1c, fasting blood sugar and improved quality of life. 7
Specific Therapies - Yoga
Very few clinical studies of yoga in type 2 diabetes have been published in recent years in the United States
Often portrayed as a serene-looking form twisted precariously into unbelievable postures on pristine remote beaches, yoga is a fundamentally a breathing practice (and difficult in the sand). Many types of yoga also include a movement-based practice, with different styles requiring varying degrees of physical fitness. Selecting the best type for you should include trying several different styles; more strenuous styles can require conditioning and should be worked toward slowly in order to prevent injury and frustration!
Very few clinical studies of yoga in type 2 diabetes have been published in recent years in the United States (my unconfirmed understanding is the Indian literature has a long history of reports documenting the benefits of yoga in diabetes). Singh et al. published an uncontrolled clinical trial of 30-40 minutes of yoga per day for 40 days and demonstrated 50 mg/dl average reduction in fasting blood sugar, a 1.2% reduction in HbA1c and a 16 mmHg reduction in systolic blood pressure, i.e. the “top number”. 8 The uncontrolled nature of this clinical study demands caution when interpreting these results, but the degree of observed improvement was much greater than what would be expected to occur spontaneously and thus I think it is safe to say some of the observed benefits where due to the yoga practice.
The second clinical trial by Skoro-Kondza et al. was an attempt to evaluate yoga therapies in a group community center. Unfortunately, low participation in this study, in part due to physical limitation and reduced conditioning, preventing evaluating the program in any meaningful manner in their study. 9 These findings reinforce the need for caution in choosing a yoga practice matched to your level of fitness and fitness goals.
Specific Therapies - Qigong
Qigong has a more medical orientation and can include specific visualization exercises reported to improve bodily function.
Similar in origin to Tai Chi, Qigong is another breathing practice with a movement component. There are some distinct differences between Tai Chi and Qigong. Qigong is reportedly easier to learn than Tai Chi because Tai Chi emphasizes long repeated forms of many breathing and movement positions, whereas Qigong tends to frequently repeat fewer, smaller movements. Also, historically, Qigong has a more medical orientation and can include specific visualization exercises reported to improve bodily function. In some cases, Qigong also involves massage or hands-on therapies, including some styles that recommend self-massage along with the visualization practices.
Two small, controlled, clinical trials have been performed evaluating Qigong in type 2 diabetes, including one at Bastyr University in Seattle, WA. An early controlled trial was published in 2002 by Tsujiuchi et al. in which 26 participant were randomized to Qigong or a waiting list. After four months, the Qigong group had an average HbA1c reduction of 0.8%, improved insulin secretion and reduced anxiety.10 In our recent clinical trial, Dr. Guan-Cheng Sun randomized participants into either a resistance training program, Qigong or no treatment. Qigong was practiced an hour per week in a group plus an hour per week at home. After 12 weeks, we observed significant reductions in fasting blood sugar, but not HbA1c, in the Qigong group compared to the other groups; we also observed a trend for improved insulin sensitivity, although this result was not statistically significant.11
Do These Different Approaches Have Different Effects?
Stress reduction is a practice and thus takes discipline and a degree of intensity of practice to be beneficial metabolically, i.e. to change your blood sugar.
Clearly practices like yoga, Tai Chi and Qigong are very similar, so how does one chose? Are there greater benefits from one vs. another? Is the practice going to be effective- for YOU?
One commonality is clear from the literature. Stress reduction is a practice and thus takes discipline and a degree of intensity of practice to be beneficial metabolically, i.e. to change your blood sugar. The clinical trials of short duration or with less frequent or less intense practice were less likely to show beneficial results. This suggests, although it cannot be known for sure, that the physical exercise component of these practices seems to be important, rather than only the stress reduction. However, our own trial of Qigong may be an exception to this statement, as our resistance exercise control exerted more energy and burned more calories but still had less metabolic benefit than our Qigong group.
We don’t really know how if these practices are different from one another and I have long advocated for a clinical trial to really compare one to another. Generally, I would recommend yoga for patients who are reasonable fit and flexible because yoga builds lean muscle mass and improves balance and posture. A seasoned yoga instructor can tailor a class to any physical limitation. Tai chi and Qigong can be done at nearly any degree of physical fitness, and thus are better options for those less physically conditioned.
“Stress” is a very individualized experience, and therefore finding an individualized practice to reduce our stress is critical to success.
“Stress” is a very individualized experience, and therefore finding an individualized practice to reduce our stress is critical to success. Creating time for a disciplined stress reduction practice can be challenging, yet there are effective approaches available for all states of physical fitness, and that are adaptable to home or community practice. Even seated versions of many stress reduction activities are available. For many, finding a Tai Chi or Qigong group leads to greater community participation and social networking- adding extra benefit! Most importantly, learning stress reduction techniques, whether strictly meditative practices or a practice with movement combined, provides you with a lifelong skill to process and move beyond stressors that can impact your long- term health and quality of life!
In part 3, I will specifically review the evidence for various stress reduction techniques, including details on biofeedback, for lowering blood pressure- so stay tuned!
Ryan Bradley, ND, MPH is a naturopathic doctor, clinical researcher and epidemiologist in San Diego, CA. He is an Associate Professor and Assistant Director of Research at the National University of Natural Medicine in Portland, OR and an Assistant Professor in the Department of Family Medicine and Public Health at the University of California, San Diego.
Where Can I find Out More Information?
More information can be found for each of these approaches at the following websites:
Medical Research on Tai Chi and Qigong: www.worldtaichiday.org/WTCQDHlthBenft.html
The Qigong Institute: www.qigonginstitute.org/main_page/main_page.php
The Institute of Qigong (Seattle): www.qigongseattle.org/index.html
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2. Surwit RS, van Tilburg MA, Zucker N, et al. Stress management improves long-term glycemic control in type 2 diabetes. Diabetes Care. Jan 2002;25(1):30-34.
3. Wang JH. Effects of Tai Chi exercise on patients with type 2 diabetes. Med Sport Sci. 2008;52:230-238.
4. Tsang T, Orr R, Lam P, Comino E, Singh MF. Effects of Tai Chi on glucose homeostasis and insulin sensitivity in older adults with type 2 diabetes: a randomised double-blind sham-exercise-controlled trial. Age Ageing. Jan 2008;37(1):64-71.
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