YOGA AND DIABETES: A MULTI-CENTRIC RESEARCH STUDY
Date
2021-01
Journal Title
Journal ISSN
Volume Title
Publisher
SVYASA
Abstract
Type 2 diabetes mellitus (T2DM) is a highly prevalent public health problem and a significant
cause of morbidity and mortality in India. With over 77 million individuals diagnosed with
T2DM, the burden of this disease is already huge. But there are two additional dimensions
which make the potential public health burden of T2DM even greater: (a) studies indicate that
about a third of the cases of diabetes remain undiagnosed and (b) the risk of progression from
prediabetes to diabetes, and the pace of this progression, are both much higher among Indians
as compared to other populations. Thus, there is urgent need to quantify the scale of the problem
– that is, to get a robust estimate of the prevalence of diabetes – so that proper public policy
can be shaped. Equally important is to implement preventative protocols for individuals at
high-risk of progressing to diabetes. Aiming for prevention at prediabetes stage (which is the
stage of increased diabetes risk) may be too late for the Indian population, given the much
quicker progression to diabetes from this stage. It is more efficacious to aim preventative
protocols at an earlier stage, before prediabetes. This points to the need for a simple, widely
implementable, multi-variate risk score for identifying high-risk individuals, potentially even
before the stage of prediabetes. The Indian Diabetes Risk Score (IDRS), which is widely used
in India, needs to be validated at a nationwide level, and potentially improved to consider better
measures of obesity. Once an individual is deemed to be in the high-risk category, there exist
several preventative interventions including (but not limited to) Metformin therapy, increased
physical activity, and dietary control. Another intervention is the ancient technique of Yoga. In
ancient Yoga texts, repeated mention is made of the efficacy of Yogic practices to benefit
diabetes risk factors such as reducing obesity, mitigating effects of chronic stress, fostering an
active lifestyle and encouraging better dietary choices. This is especially the case with the
practices of Haöha Yoga, including techniques that have made Yoga famous the world over:
äsana (physical postures), ñaö-karma (purification practices), präìäyäma (breathing exercises),
etc. A thorough examination of Haöha Yoga Pradépika reveals that these techniques reduce β cell dysfunction and increase insulin sensitivity via multiple pathways, thereby bringing about
diabetes risk reduction and glycemic control. Existing scientific studies provide a
preponderance of evidence to back the claims of Yogic texts. Specifically, we find studies
reporting that (a) Yoga is effective in mitigating diabetes risk factors such as obesity and stress
(b) Yoga effects glycemic control in individuals with diabetes and (c) the mind-body
integrative aspect of Yoga fosters behavioral modifications that help one sustain better
nutritional habits and a more active lifestyle. These findings hint strongly that a Yoga-based
Lifestyle Protocol (YLP) can be a very effective adjunct to both prevention of diabetes and for
glycemic control among individuals with diabetes. While YLP has been studied in smaller
cohorts and/or in controlled circumstances where it is easier to ensure adherence to the
protocol, it has not yet been studied in a large community setting to determine whether it has
the necessary characteristics of simplicity, accessibility, and inexpensiveness so that it can be
applied as a mitigation to a public health problem (diabetes risk reduction and glycemic
control).
AIMS AND OBJECTIVES
The present study seeks to analyze data from Niyantrita Madhumeha Bharata Abhiyaan 2017
(Diabetes Free India Study 2017, hereinafter simply NMB-2017) to (a) improve the screening
characteristics of the Indian Diabetes Risk Score (IDRS) by incorporating a better
anthropometric measure of obesity, so that it can be used in the field to identify individuals
who have a high risk of developing diabetes (b) test the potency of yoga-based lifestyle protocol
(YLP) against diabetes risk reduction among high-risk individuals who are not yet in the prediabetes stage, in a large community setting and (c) test the efficacy of yoga as an adjunct
to standard care for glycemic control among individuals with diabetes.
METHODS
PARTICIPANTS
This study included three separate analyses:
(a) Using a better measure of obesity to increase specificity of IDRS
Using data from a nationwide randomized cluster sample survey (NMB-2017 Phase 2), 7496
adults at high risk for type 2 diabetes (as determined by IDRS ≥ 60) were analyzed. Waist
Circumference (WC), Body Mass Index (BMI), and a composite obesity measure combining
the two (BMIWC) were evaluated using Odds Ratio (OR), and Classification scores (Sensitivity,
Specificity, and Accuracy). These were validated using Indian Diabetes Risk Score (IDRS) by
replacing WC with BMI and BMIWC, and calculating Sensitivity, Specificity, and Accuracy.
(b) YLP for diabetes risk reduction
In a cluster randomized trial (NMB-2017 Phase 2) in 80 clusters from India, participants with
normal HbA1c (< 5.7%) but screened for diabetes risk (IDRS ≥60) were randomly assigned in
a 1:1 ratio to intervention and control groups, n=2316:2134, respectively. The primary outcome
was conversion from normoglycemia to diabetes. Absolute and Relative risk reductions were
estimated based on marginal probabilities.
(c) YLP for glycemic control
In a cluster randomized trial (NMB-2017 Phase 2) in 80 clusters from India, participants with
prior diagnosis of diabetes and/or HbA1c levels in diabetes range (≥ 6.5%) were randomly
assigned in a 1:1 ratio to intervention and control groups, n=1820:1572, respectively. Mean HbA1c reduction was calculated for each group, and independent samples t-test was used to
test significance. Heterogeneity of treatment effects were calculated for subgroups with fair
and poor glycemic control.
DESIGN
NMB-2017 was a pan-national, two-phased study. Phase 1 was a nationwide cross sectional
survey using a multi-level stratified cluster sampling technique with random selection among
urban and rural populations, with the objective of collecting data on diabetes status and diabetes
risk. Phase 2 was a sub-sample of phase-1 participants who were deemed high-risk (as
determined by IDRS ≥ 60) or had a previous diagnosis of diabetes. Phase 2 participants went
through further assessments in the form of blood tests and more detailed questionnaire.
ASSESSMENTS
i. Anthropometric measures (ordinal): Height (in cm), Weight (in kg), and Waist
Circumference (in cm)
ii. Derived measures (ordinal): BMI [Weight(in kg)/Height(in m)2
]
iii. Blood HbA1c levels (in DCCT %) (Ordinal)
iv. Via questionnaire (Categorical): Age, Family history of Diabetes, and levels of physical
activity. Note: The questionnaire collected more information than detailed here (see
Appendix 5), but they were not used in this analysis.
INTERVENTION
Intervention included practice of yoga-based lifestyle modification protocol (YLP) for 9
consecutive days, followed by daily home and weekly supervised practices for 3 months. In
the diabetes risk reduction study, the control-cluster received standard of care advice for
diabetes prevention. In the glycemic control study, the control-cluster received standard care
for T2DM.
RESULTS
Study 1
BMIWC had higher OR (2·300) compared to WC (1·87) and BMI (2·26). WC, BMI, and BMIWC
were all highly Sensitive (0·75, 0·81, 0·70 resp.). But BMIWC had significantly higher
Specificity (0.36) when compared to WC and BMI (0.27 each). IDRSWC, IDRSBMI, and
IDRSBMIWC were all highly Sensitive (0·87, 0·88, 0·82 resp.). But IDRSBMIWC had significantly
higher Specificity (0·39) compared to IDRSWC and IDRSBMI (0·30, 0·31 resp.).
Study 2
Among individuals at high risk for diabetes (as determined by IDRS ≥ 60) but with normal
glycemic levels at baseline, the YLP was found to be significantly effective in halting
progression to diabetes as compared to standard of care (RRR 68.64%, 95% CI 64.73 – 73.48).
Study 3
Among individuals with diabetes, YLP showed a significantly greater reduction in HbA1c
levels (µ=1.31, σ=1.40) compared to control arm (µ=0.45, σ=0.55); t(∞) = 22.68, p < 0.001.
This effect was even more pronounced in individuals with poor glycemic control at baseline,
with the difference in mean reduction of HbA1c levels between yoga and control being
significantly higher (µ=1.61, σ=1.29) compared to individuals with fair glycemic control at
baseline (µ=0.35, σ=0.83); t(∞) = 15.73, p < 0.001.
COLCULSIONS
Both WC and BMI are good predictors of risk for T2DM, but BMIWC is a better predictor, with
higher Specificity; this may indicate that Indians with high values of both central (high WC)and general (BMI> 23) obesity carry higher risk for type 2 diabetes than either one in isolation.
Using BMIWC in IDRS improves its performance on Accuracy and Specificity. Substantive
influence of yoga-based lifestyle intervention was observed against diabetes risk reduction on
the high-risk Indian cohort. Among individuals with diabetes, YLP reduced glycemic levels,
with the effect being more significant in people who had poor glycemic control to begin with.
This might indicate that YLP can be very valuable clinically as an adjunct to standard treatment
for individuals whose serum glucose levels are not responsive to standard care. Overall, our
findings point to the efficacy of YLP as an effective strategy to combat the epidemic of diabetes
from both preventative and treatment perspectives.
Description
Keywords
Yoga, Type 2 Diabetes Mellitus, Diabetes, Body Mass Index, Indian Diabetes Risk Score