This edition of Educator’s Corner defines and describes yoga and its common components, evaluates the scientific evidence of yoga as an adjunctive treatment modality for diabetes, and provides “practice pearls” for implementing yoga in the clinic and/or in diabetes self-management curricula and programs.
The science of yoga is rooted in traditional Indian medicine. Ancient texts vividly describe clinical features and complications of what modern medicine labels as Type 1 diabetes and Type 2 diabetes.1 In Ayurveda, a component of the traditional Indian medical system, the Sanskrit word for diabetes mellitus is “madhumeha,” which translates as “sweet urine” disease. In these ancient texts, treatment of madhumeha was based on the associated clinical features (i.e., body anthropometrics—thin versus overweight) and typically included meditation (dhyana) and mantra (dharana), breathing exercises (pranayama), dietary regimens (i.e., herbs and spices, various combinations of dietary protein and fat) and physical movement—yoga postures (asanas).2 This ancient or Eastern approach in many ways parallels current allopathic or Western evidenced-based practice of lifestyle modification to include an individualized nutrition prescription, stress management, relaxation response training and positive coping skills, and purposeful movement with a reduction in sedentary behaviors.3 The latter can be accomplished in a ‘two-for-one’: yoga. Is there evidence that yoga, a mindful-coordination of breath with movement, facilitates improvements in biomarkers (glycemic control, hemodynamic response, metabolic indices, and psychosocial parameter) of diabetes health?
Over the last decade or so, there has been an increase in the number of scientific publications 1,5,6,8,9 as well as lay articles11 on the behavioral and biomedical benefits of yoga on various chronic-lifestyle diseases such as cardiovascular disease,5,9,12 anxiety,5,8,9,10 depression,5,8,9,10 post-traumatic stress disorder,5,8,9 disordered eating and eating disorders,13-15 obesity,16 chronic pain,17-20 cancer21, 22 and diabetes.1,6,12,12, 23, 25-28
Despite methodological issues (i.e., limited sample size, lack of blinding and randomization in some studies, sparse analytics in others, heterogeneity, clinical versus statistical significance, and lack of comparators), the preponderance of data nonetheless indicates improved physiological and psychological benefits of yoga in those with diabetes, most notably those with Type 2 diabetes.
Evidence of yoga’s benefits
A pilot study comparing a yoga intervention with a walking control group reported a significant decrease in weight, BMI and waist circumference compared to the walking group. Reductions in fasting blood sugar (FBS), postprandial blood glucose (PPBG), serum insulin, insulin resistance, blood pressure or cholesterol were not observed. The researchers also noted statistically significant improvements in measures of psychological well-being in both groups.23 Interestingly, noted improvements in mood and positive affect, which were greater in the yoga group, are of clinical and empirical interest. One large randomized controlled trial found that increasing positive affect significantly improved physical activity maintenance at one year.24 This suggests a potential positive behavior change advantage for the yoga group versus the walking group.
In a randomized parallel study of a three-month yoga intervention in individuals with Type 2 diabetes, researchers observed significant (p<0.05) reductions in total cholesterol (TC), LDL cholesterol (LDL-c) and triglycerides (TG) with a nonsignificant elevation in HDL cholesterol (HDL-c) in the yoga group versus the control group. The yoga group also had a nonsignificant reduction in BMI and a significant reduction in both weight and waist-to-hip ratio. Interestingly and unfortunately, the control group did not fare so well, showing significant increases in body weight, nonsignificant increases in BMI, TC, LDL-c and TG, and a corresponding decrease in HDL-c.12
Though yoga itself is considered a type of mindfulness in many circles, a recent study compared standard care plus yoga asana combined with mindfulness eating on glycemic parameters in women with gestational diabetes. The results revealed statistically significant (p<0.05) improvements in FBS, PPBG and HbA1c in the intervention group (standard care plus yoga asana and mindfulness eating) versus the control group (standard care alone).25
A more recent paper also evaluated a dual intervention of yoga and peer support on glycemic control, pharmacological adherence and anthropometric measures. This open-label, parallel three-armed randomized controlled trial compared a yoga intervention plus continuation of current pharmacotherapy and nutrition prescription, peer support with continuation of medications and diet, and standard care (oral meds plus basic lifestyle education). Results were mixed: FBS improved in all three groups but did not reach statistical significance, with the yoga group experiencing the greatest improvement. The yoga cohort also experienced a decrease in HbA1c, while the other two cohorts experienced an increase in HbA1c. Again, these differences did not reach statistical significance. Relative to pharmacotherapeutic adherence, all three groups benefitted from their respective interventions, but again, the results did not reach statistical significance. Other metabolic biomarkers (blood pressure, lipidemia and anthropometric measures) were similarly mixed: improvements in diastolic blood pressure and hip circumference in the yoga intervention compared to the other groups were statistically significant, but other markers were variable (i.e., null change or slight change not reaching statistical significance in the direction of yoga and peer support). The researchers concluded that the interventions showed incremental improvements without significant adverse effects, and that longer duration studies with larger sample sizes are needed to ascertain the absolute benefits of the interventions.26
Two recent systematic reviews and meta-analyses of yoga for adults with Type 2 diabetes were likewise inconclusive about the absolute benefits of yoga for improving diabetes outcomes. However, yoga may yield benefits as an adjunct to standard care. Of interest, a review of 17 randomized controlled trials documented beneficial effects of yoga as an adjunctive treatment to standard care (medication, lifestyle education and support) that reached statistical significance (p<0.00001) for FBS, PPBG and HbA1c.27 Furthermore, an incredibly comprehensive review article noted the additive benefits of yoga to standard care on glycemic control (FBS, PPBG, HbA1c, serum insulin), lipids (decreased TC, LDL-c, TG and increased HDL-c) and anthropometric measures (body weight, BMI and waist-to-hip ratio). Although the data were more limited for other health indices, yoga interventions showed potential to lower oxidative stress and blood pressure, enhance pulmonary and autonomic nervous system function, mood, sleep and quality of life, while possibly reducing medication usage.6
Despite methodological issues, quantitative studies have demonstrated physiological improvements with a yoga intervention. Concurrently, these papers and others have proposed the mechanisms by which yoga improves said indices. And although the risk-to-benefit ratio is favorable, one question remains: on a qualitative patient experience level, does it matter? While participants of a yoga study stated, “I could move mountains,” Alexander et al. concluded that maintaining a yoga practice presents challenges similar to adopting other lifestyle changes. Furthermore, they emphasized the necessity of diabetes educators and related clinicians to support the adoption and maintenance of all lifestyle changes.28
So, the next question is, how to bring yoga to the clinic? The sidebar provides seven ideas—one for each day of the week—to bring “Yoga to Life!”
As teachers—be it certified diabetes educators, mid-level practitioners or physicians—we are called upon to teach, inspire and motivate patients to follow our individualized but evidenced-based recommendations. You can be certain that recommending movement in the form of yoga asana will, at least, decrease sedentary behavior and quite possibly improve glycemia, lipidemia, anthropometry, sleep hygiene, mood and positive affect.
Traditionally yoga classes end with the salutation “Namaste.” In Sanskrit, this loosely translates as “the teacher in me salutes the teacher in you.”4
Asana: Sanskrit word meaning “physical posture or pose”4
Dharana: Sanskrit word meaning “focused or intentional concentration”4
Dhyana: Sanskrit word for “meditation”4
Hatha yoga: specific branch or style of yoga that predominantly focuses on the asanas or activity with a secondary focus on dharana and dhyana. In Western cultures, hatha yoga itself encompasses such styles as Ashtanga, Bikram, Iyengar, Kundalini, Viniyoga and Vinyasa. In the U.S., hatha yoga is characteristically but inaccurately considered a gentler or less vigorous style of yoga.4-6
Mantra: syllable, sound (i.e., “OM”), word phrase or affirmation repeated aloud or in one’s conscious thought intended to provide dharana (focus) in preparation for or as part of dhyana (meditation)4
Mindfulness: moment-by-moment nonjudgmental (observational) awareness7
Mudra: hand placement or hand gesture typically used in meditation4
Pranayama: focused breath work such as diaphragmatic (belly breathing) or ujjayi (ocean) breathing or alternate nostril breathing4
Bring yoga to life
1. Write a yoga (a.k.a. movement or exercise) prescription for your patients. Studies show that when “exercise” is written on a prescription pad, patients are more likely to follow through.29-31 Since most yoga classes last 60 to 75 minutes, write “attend 2 yoga classes weekly.” Thus, patients would achieve at least 120 minutes to quite possibly the recommended 150 minutes weekly of movement.29-31
2. Create a list of yoga studios or classes in your service area. Rural communities often offer classes at a YMCA, Jewish community centers, community recreation centers and/or senior living programs/facilities. Patients in suburban and metropolitan areas are likely to have these same locations as well as yoga studios. Many large teaching hospitals often have classes on site.
3. If teaching diabetes self-management training (DSMT) classes, invite a qualified registered yoga teacher (RYT) through Yoga Alliance (yogaalliance.org) to teach pranayama, a guided meditation, or gentle asana sequence as part of the curricula. Depending on the curriculum’s written language, this kinesthetic learning module could fall under either exercise or coping/stress management.
4. Alternatively, if inclusion as part of the DSMT curricula is not feasible, offer yoga and guided meditation as a topic for a support group meeting.
5. Create yoga asana, pranayama and meditation stress management handouts. Be sure to include a list of apps or DVDs.
6. If your lobby or waiting area has closed circuit TV or other educational audio or video, include a module or loop of gentle yoga asana or guided meditation.
7. Take a class or two yourself. Better yet, buy a pass to your local yoga studio. Commit to 150 minutes of classes weekly—the minimum amount of time recommended for health benefits—for the duration of the pass. Not only will you personally reap the benefits of yoga, you may also develop a greater appreciation of the challenge of implementing lifestyle changes.32 Although I believe we as educators and clinicians are a passionate and compassionate group, it is equally humbling and rewarding to walk in another’s shoes, even if only for a moment.
Access additional resources and practical information to enhance the care and treatment of your diabetes patients.