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Trial registered on ANZCTR


Registration number
ACTRN12613000816752
Ethics application status
Approved
Date submitted
19/07/2013
Date registered
24/07/2013
Date last updated
26/07/2013
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effects of regular yoga practice in individuals with and without metabolic syndrome
Scientific title
Effects of a 12-week hatha yoga program on metabolic risk factors, physiological stress, health-related physical fitness, and mental health in individuals with and without metabolic syndrome
Secondary ID [1] 282861 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Metabolic syndrome 289673 0
Condition category
Condition code
Metabolic and Endocrine 289991 289991 0 0
Metabolic disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The 12-week hatha yoga program:
This program will consist of 12 weekly classes of one hour duration. All classes will be taught by the same instructor, who has three years of hatha yoga instructing experience. Sixty yogic poses and breathing commonly taught in fitness centres and private yoga studios will be instructed and practiced throughout the program. Modification of some poses will be suggested if subjects have limitations in their flexibility. Props such as mats and blocks will be used.

Adherence will be documented via attendance records recorded by the yoga teacher at each yoga intervention session. Each participant will be required to fill in “Yoga Self-Practice Weekly Record Sheet” which recorded the duration of self-practice. The completed sheets will be collected in the lesson of the following week, except the sheet recorded the twelfth week will be collected in post intervention assessment session. Apart from the yoga program, the yoga participants will be advised to maintain their routine activities and not to begin other exercise or mind-body program during the course of the study.
Intervention code [1] 287557 0
Lifestyle
Comparator / control treatment
No treatment
Control group
Active

Outcomes
Primary outcome [1] 290039 0
In this study, the instruments with established validity and reliability will be used to determine each outcome.

A. Outcomes related to metabolic risk factors:
Outcome 1. Blood pressure:
Blood pressure measurements will be measured in seated position according to the American Heart Association Scientific Statement (Pickering et al., 2005). The average of the second and third systolic and diastolic pressure reading will be used in the analyses.
Timepoint [1] 290039 0
At baseline and post-intervention (12 weeks)
Primary outcome [2] 290064 0
Outcome 2. Waist circumference (WC):
WC will be measured at the nearest 0.5 cm at the shortest point below the lower rib margin and the iliac crest.
Timepoint [2] 290064 0
At baseline and post-intervention (12 weeks)
Primary outcome [3] 290065 0
Outcome 3. Fasting blood glucose (FBG)
FBG will obtained by taking blood samples from subjects and sent the samples to the laboratory for analysis.
Timepoint [3] 290065 0
At baseline and post-intervention (12 weeks)
Secondary outcome [1] 303825 0
Outcome 4. Triglycerides (TG):
TG will obtained by taking blood samples from subjects and sent the samples to the laboratory for analysis.
Timepoint [1] 303825 0
At baseline and post-intervention (12 weeks)
Secondary outcome [2] 303864 0
Outcome 5 High-density lipoprotein cholesterol (HDL-C):
HDL-C will obtained by taking blood samples from subjects and sent the samples to the laboratory for analysis.
Timepoint [2] 303864 0
At baseline and post-intervention (12 weeks)
Secondary outcome [3] 303865 0
B. Physiological stress:
Outcome 6. Cortisol level:
The measurement of salivary cortisol provides a non-invasive and reliable tool for investigation of HPA axis activity. Subjects will be instructed to obtain salivary samples at the same time to control the circadian rhythm (Kirschbaum & Hellhammer, 1989). Samples will be sent to the laboratory for electrochemiluminescence immunoassay. Raw cortisol values will be log transformed to reduce skewness of their distribution.
Timepoint [3] 303865 0
At baseline and post-intervention (12 weeks)
Secondary outcome [4] 303866 0
C. Health-related physical fitness:
C1. Cardiovascular endurance
Outcome 7. Resting heart rate:
Resting heart rate will be measured following a seated ten-minute rest period. The heart rate will be detected by electronic device (Polar Electro, Finland).
Timepoint [4] 303866 0
At baseline and post-intervention (12 weeks)
Secondary outcome [5] 303867 0
Outcome 8. VO2max (Maximum Oxygen Consumption):
The concept of cardiovascular endurance is an individual’s aerobic capacity, and the most reliable and valid measure of aerobic capacity is VO2max (Morrow, Jackson, Disch, & Mood, 2005). Bruce Protocol will be applied in the study. This test consists of several 3-minute stages, where the speed and grade are changed each stage, using the treadmill as a mode (ACSM, 2010).
Timepoint [5] 303867 0
At baseline and post-intervention (12 weeks)
Secondary outcome [6] 303868 0
C2. Muscular endurance:
Outcome 9. Upper body muscular endurance (Push-up test)
The Canadian Standardized Test of Fitness - Push-up will be conducted to measure the muscle endurance of upper-body muscles. The test procedure for the measurement will be according to the descriptions from Canadian Society for Exercise Physiology (Canadian Society for Exercise Physiology, 2003, as cited in ACSM, 2010).
Timepoint [6] 303868 0
At baseline and post-intervention (12 weeks)
Secondary outcome [7] 303869 0
Outcome 10. Abdominal muscle endurance:
The Canadian Standardized Test of Fitness - Curl-up Test will be conducted to measure the muscle endurance of the abdominal muscle groups, respectively. The test procedure for the measurements will be according to the description from Canadian Society for Exercise Physiology (Canadian Society for Exercise Physiology, 2003, as cited in ACSM, 2010).
Timepoint [7] 303869 0
At baseline and post-intervention (12 weeks)
Secondary outcome [8] 303870 0
C3. Flexibility
Outcome 11. Left leg flexibility:
The modified back-saver sit-and-reach test (MBS test) will be used to test of trunk flexion. The MBS test is a comparative better test to measure the low back and hamstring flexibility than other protocols as its similarity of criterion-related validity in women but it has better criterion-related validity in men, more practical as it requires minimal preparation time and equipment. It also eliminates excessive posterior compression of the vertebral disk when performing a single leg reach (Hui & Yuen, 2000).
Timepoint [8] 303870 0
At baseline and post-intervention (12 weeks)
Secondary outcome [9] 303871 0
Outcome 12. Right leg flexibility:
The modified back-saver sit-and-reach test (MBS test) will be used to test of trunk flexion. The MBS test is a comparative better test to measure the low back and hamstring flexibility than other protocols as its similarity of criterion-related validity in women but it has better criterion-related validity in men, more practical as it requires minimal preparation time and equipment. It also eliminates excessive posterior compression of the vertebral disk when performing a single leg reach (Hui & Yuen, 2000).
Timepoint [9] 303871 0
At baseline and post-intervention (12 weeks)
Secondary outcome [10] 303872 0
C4. Body composition:
Outcome 13. Body weight (BW):
BW will be measured in light clothing and without shoes to the nearest 0.5 kg at the start and the end of the program.
Timepoint [10] 303872 0
At baseline and post-intervention (12 weeks)
Secondary outcome [11] 303873 0
Outcome 14. Body mass index
BMI will be calculated as weight in kilograms divided by height in meters squared. (Height will be measured to the nearest 0.5 cm)
Timepoint [11] 303873 0
At baseline and post intervention (12 weeks)
Secondary outcome [12] 303874 0
D. Physical activity level
Outcome 15. IPAQ
The short (7 day) form of the International Physical Activity Questionnaire (IPAQ) (Craig et al., 2003) will be applied to investigate the subjects’ physical activity level. A study was carried out to examine the reliability and validity of IPAQ in 12 countries (Craig et al., 2003). The result showed that IPAQ had reasonable measurement properties for monitoring population levels of physical activity among 18 to 65 years old adults in the diverse sample settings. Spearman’s Rho clustered around 0.8 indicating reliable responses between repeat administrations for all versions of the IPAQ. The short IPAQ has been translated to Chinese and has demonstrated adequate reliability and validity for the measurement of total physical activity in a Chinese population (Macfarlane, Lee, Ho, Chan, & Chan, 2007).
Timepoint [12] 303874 0
At baseline and post-intervention (12 weeks)
Secondary outcome [13] 303875 0
E. Mental health:
Outcome 16. Health related quality of life (HRQOL)
The MOS 36-Item Short-Form Health Survey (SF-36) (Ware, Kosinski, & Gandek, 2000) includes one multi-item assessing each of eight health concepts: 1) physical functioning; 2) role limitations due to physical problems, 3) social functioning, 4) bodily pain, 5) general mental health, 6) role limitations due to emotional problems, 7) vitality, 8) general health perceptions. The internal consistency of the SF-36 ranged from .63 to .96 and the test–retest reliability ranged from .60 to .81 (Ware, Kosinski, & Gandek, 2000).
Timepoint [13] 303875 0
At baseline and post-intervention (12 weeks)
Secondary outcome [14] 303876 0
Outcome 17. Perceived stress:
Perceived Stress Scale (PSS) assesses the degree to which an individual appraises situations in his or her life as stressful (Cohen, & Williamson, 1988). It consists of 10 Likert-type items designed to assess how unpredictable, uncontrollable, and overloaded respondents perceived their lives to be. A lower score is indicative of lower perceived stress and score can range from 0 to 56. The PSS has been shown to be valid, with internal reliability as determined by Cronbach’s a of 0.902 (Smith et al., 2008).
Timepoint [14] 303876 0
At baseline and post-intervention (12 weeks)
Secondary outcome [15] 303877 0
Outcome 18. Depression:
The Centre for Epidemiologic Studies Depression Scale (CES-D) is a 20-item self-report scale to measure depressive symtomatology in the general population. The scale has high internal consistency with Cronbach’s a of 0.85 (Radloff, 1977). It yielded Cronbach’s a of 0.92 in the study of Mitchell et al. (2007).
Timepoint [15] 303877 0
At baseline and post-intervention (12 weeks)
Secondary outcome [16] 303878 0
Outcome 19. Anxiety (STAI):
State-Trait Anxiety Inventory (STAI) is a 40-item self-report scale to evaluate state and trait anxiety (Spielberger, 1983). Cronbach’s a for the state and trait subscales were 0.92 and 0.96, respectively, in the study of Mitchell, Mazzeo, Rausch, and Cooke (2007).
Timepoint [16] 303878 0
At baseline and post-intervention (12 weeks)
Secondary outcome [17] 303879 0
Outcome 20. Self-esteem
Rosenberg Self-Esteem Scale (RSES) (Rosenberg, 1965) consists of 10-items, which examines the global self-esteem of individuals. The original scale is typically replaced with a Likert-type response format using a four-point scale anchored by 1 (Always Disagree) and 4 (Always Agree) (Sheasby, Barlow, Cullen, & Wright, 2000). The reproducibility of the scale is 93%, scalability of items is 73%, and scalability of individuals is 72 % (Rosenberg, 1965). Internal consistencies in the study of Elavsky and McAuley (2007) were good (a ranged from .89 to .92 for baseline and post-intervention assessments, respectively).
Timepoint [17] 303879 0
At baseline and post-intervention (12 weeks)
Secondary outcome [18] 303880 0
Outcome 21. Attendance of the yoga program (for intervention group only)
Timepoint [18] 303880 0
The time of the yoga program
Secondary outcome [19] 303881 0
Outcome 22. Attrition rate of the study
Timepoint [19] 303881 0
The number of participants recruited at baseline and the number of participants dropouts at post-intervention

Eligibility
Key inclusion criteria
For all eligible participants, they should be
1) Chinese national and able to communicate in Cantonese
2) aged 18 or above
3) physically and mentally capable of practicing yoga safely

The current study will include both participants with and without metabolic syndrome. The researcher will categorize the participants into either with metabolic syndrome group or without metabolic syndrome group based on the WC, blood pressure, TG, HDL-C, and FBG at baseline assessment of the participants.

Participants will be categorized participants to metabolic syndrome group if they meet at least three of the revised NCEP-ATP III clinical diagnosis criteria for Asian populations (Grundy et al., 2005):
1) Waist circumference (WC): greater than or equal to 90 cm in men; greater than or equal to 80 cm in women
2) Triglyceride (TG): greater than or equal to 150 mg/dL or on drug treatment for elevated TG
3) High-density lipoprotein cholesterol (HDL-C): less than 40 mg/dL in men, less than 50 mg/dL in women or on drug treatment for reduced HDL-C
4) Systolic blood pressure (SBP): greater than or equal to 130 mmHg or diastolic blood pressure (DBP) greater than or equal to 85 mmHg or on antihypertensive drug treatment in a patient with a history of hypertension
5) Fasting blood glucose (FBG): greater than 110 mg/dL or on drug treatment for elevated glucose

For those who do not meet at least 3 of the above criteria, they will be categorized in a non-metabolic syndrome group.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1) Regular participation of (> 1/week) yoga for last 3 months or concurrent use of yoga, Qigong or meditation
2) Pregnancy or breast feeding
3) Anticipate any planned life stressors (moving, divorce, changing job, etc.), shift work, or transcontinental travel during the intervention
4) Undergo any other concurrent nonpharmacological treatment of MetSyn
5) Chronic illnesses: cancer, kidney disease, cirrhosis, rheumatologic diseases, or chronic inflections
6) Current major psychiatric illnesses, cognitive impairment, or substance abuse
7) Concurrent enrollment in any other studies, experimental therapies, or blinded treatments

Study design
Purpose of the study
Prevention
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis
Statistical analysis:
The statistical analysis will be conducted using SPSS 16.0 software (SPSS Inc, Chicago, Illinois). Sample description will be described; baseline characteristics, retention and program adherence, and all other outcome measures will be analyzed and reported. Paired t test and independent t test will be used to analyze continuous variables. Mann-Whitney test will be used to analyze continuous variables which did not have normal distribution. Chi square test will be employed to compare categorical variables. Statistical significance will be inferred by a two-tailed p value of .05 or less.

Sample size estimation:
Due to lacking of local research experience in running Hatha yoga intervention within the community (Hong Kong), the researcher estimated the attrition rate by referring to three overseas studies with similar study setting which illustrated a 22.0% attrition for a 12-week Hatha yoga program (Moadel et al., 2007), a 15.3% attrition for a 10-week Hatha yoga program (Smith et al., 2007), and a 8.33% attrition for another 10-week program (Booth-LaForce et al., 2007). Because the study intervention duration will last for 12 weeks, a 22.0% attrition rate will be estimated. Based on an earlier study (West et al., 2004), a sample size of 36 participants per group will be required to obtain an 80% power for detection of a difference of 0.08 g/dl in salivary cortisol level between the yoga group (intervention group) and the control group when performing a two-tailed test at a = 0.05. With consideration of 22% attrition rate, the target sample size of the study will be determined to be 46 participants for each group.
Estimation of total sample size = 46 X 4 groups (yoga group with metabolic syndrome + control group with metabolic syndrome + yoga group without metabolic syndrome + control group without metabolic syndrome) = 184 persons

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 5231 0
Hong Kong
State/province [1] 5231 0

Funding & Sponsors
Funding source category [1] 287637 0
University
Name [1] 287637 0
Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong
Address [1] 287637 0
Department of Medicine and Therapeutics, 9/F, Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
Country [1] 287637 0
Hong Kong
Primary sponsor type
University
Name
Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong
Address
Department of Medicine and Therapeutics, 9/F, Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
Country
Hong Kong
Secondary sponsor category [1] 286379 0
None
Name [1] 286379 0
Address [1] 286379 0
Country [1] 286379 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 289608 0
Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Reseaerch Ethics Committee
Ethics committee address [1] 289608 0
Flat 3C, Block B, Staff Quarters, Prince of Wales Hospital, Shatin, Hong Kong
Ethics committee country [1] 289608 0
Hong Kong
Date submitted for ethics approval [1] 289608 0
Approval date [1] 289608 0
27/04/2010
Ethics approval number [1] 289608 0

Summary
Brief summary
Physical inactivity is one of the main causes of major noncommunicable diseases and contributes substantially to the global burden of disease, death and disability. To reverse the trend towards inactivity, it is important to promote physical activities with low participation barrier and numerous benefits to encourage sedentary individuals to become physically active. Yoga has been increasingly popular and practiced as a low-to-moderate intensity physical activity in recent years. Yoga originated in India more than 5000 years ago and its principle is to achieve the integration of body, mind, and spirit. Growing evidence suggests the beneficial effects of Hatha yoga on various ailments, yet potential long-term effects of yoga on health are under-researched. Interpretation of and comparisons across many existing studies are limited by methodological problems. The current study aims to investigate the effects of yoga on physical and mental health in individuals with and without metabolic syndrome.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 41546 0
Prof Jean Woo
Address 41546 0
Department of Medicine & Therapeutics, 9/F., Clinical Sciences Building, Prince of Wales Hospital, Shatin, N.T. Hong Kong SAR
Country 41546 0
Hong Kong
Phone 41546 0
+85226323493
Fax 41546 0
+85226373852
Email 41546 0
jeanwoowong@cuhk.edu.hk
Contact person for public queries
Name 41547 0
Miss Lau Hoi Lam
Address 41547 0
Room 124021, 10/F, Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong SAR
Country 41547 0
Hong Kong
Phone 41547 0
+85290220861
Fax 41547 0
Email 41547 0
lauhlcaren@gmail.com
Contact person for scientific queries
Name 41548 0
Miss Lau Hoi Lam
Address 41548 0
Room 124021, 10/F, Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong SAR
Country 41548 0
Hong Kong
Phone 41548 0
+85290220861
Fax 41548 0
Email 41548 0
lauhlcaren@gmail.com

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary