Feasibility of yoga as a complementary therapy for patients with type 2 diabetes: The Healthy Active and in Control (HA1C) study

Highlights

• A yoga intervention with US adult diabetics showed high acceptability

• Over 80% of sessions were attended

• Study completion rate was 92%

• Over half of those given yoga continued practice through 6-month follow up

• Improvements were seen in diabetes self-care, distress and quality of life measures

Abstract

Objectives

This study:Healthy Active and in Control (HA1C), examined the feasibility and acceptability of yoga as a complementary therapy for adults with Type-2 Diabetes (T2DM).

Design

A 2-arm randomized clinical trial comparing Iyengar yoga with a supervised walking program.

Setting

Hospital based gym-type facility and conference rooms.

Interventions

Participants were randomized to a 12-week program of either; (1) a twice weekly Iyengar yoga, or (2) a twice-weekly program of standard exercise (SE).

Main Outcome Measures

Primary outcomes assessed feasibility and acceptability, including enrollment rates, attendance, study completion, and participant satisfaction. Secondary outcomes included HbA1c, physical activity, and measures of diabetes-related emotional distress, self-care and quality of life (QOL). Assessments were conducted at baseline, end of treatment, 6-months and 9-months post-enrollment.

Results

Of 175 adults screened for eligibility, 48 (30 women, 18 men) were eligible and enrolled. The most common reasons for ineligibility were orthopedic restrictions, HbA1c levels <6.5 and BMI > 42. Session attendance was high (82% of sessions attended), as was follow-up completion rates (92%). Program satisfaction rated on a 5-point scale, was high among both Yoga (M = 4.63, SD = 0.57) and SE (M = 4.77, SD = 0.52) participants. Overall 44 adverse events (26 Yoga, 18 SE) were reported. Of these, six were deemed “possibly related” (e.g., neck strain, back pain), and 1 “probably related” (ankle pain after treadmill) to the study. Yoga produced significant reductions in HbA1c. Median HbA1c at 6 months was 1.25 units lower for Yoga compared to SE (95% CI: -2.54 -0.04).

Greater improvements in diabetes self-care, quality of life, and emotional distress were seen among Yoga participants than among SE participants. Increases in mindfulness were seen in Yoga but not in SE.

Conclusions

The yoga intervention was highly feasible and acceptable, and produced improvements in blood glucose and psychosocial measures of diabetes management.

Introduction

Diabetes affects more than 29 million American adults and is the seventh leading cause of death in the United States.¹ The American Diabetes Association states that regular physical activity is critical to the management of blood glucose and overall health for individuals with Type 2 diabetes (T2DM).² However, individuals with T2DM typically find compliance with this recommendation difficult.³,⁴ In the United States, there remains a need for effective, acceptable, feasible and empirically validated strategies to promote physical activity among those with T2DM.

Yoga practice involves a physical activity component (postures/asana), and a relaxation component (meditation, shavasana). With its focus on controlling breath, holding postures, and meditation, yoga increases the practitioner’s attention to bodily sensations and present moment experiences, thus contributing to yoga as a mindfulness-based activity.⁵,⁶ Mindfulness may help improve diabetes management by increasing individuals’ ability to recognize emotional stress and to respond with more effective coping strategies.⁷,⁸

Randomized controlled trials (RCT) with healthy adults and those with T2DM have shown a benefit of yoga on stress reduction.9, 10, 11, 12, 13, 14 Since empirical studies show that stress leads to poor food choices,^15,16 yoga may benefit diabetics by improving dietary control. RCTs in non-diabetics have shown improved dietary outcomes after yoga interventions.17, 18, 19, 20

A systematic review of yoga studies among adults with T2DM (found 12 RCTs encompassing 864 patients),²¹ concluded that while overall results showed a significant reduction in HbA1c and fasting blood glucose (FBG), there was significant heterogeneity among studies due to methodological weaknesses. A more recent review (included 8 RCTs with a total of 842 participants) reiterated this same conclusion;²² that while studies of yoga as a method for improving glycemic control have shown promise overall, there is great heterogeneity between studies. Moreover, of the 13 unique studies included in those systematic reviews^21,22 most studies (N = 9) were conducted in India and none in the U.S. There is sufficient evidence to suggest that yoga has the potential to positively impact stress, diet and other self-care tasks that contribute to improved glycemic control; however, this has not yet been tested among individuals with T2DM. Additionally, it is not clear whether a yoga intervention would be both feasible and acceptable to American adults with T2DM.