Tai Ji Quan as an exercise modality to prevent and manage cardiovascular disease:A review

Ruth E.Taylor-Piliae

College of Nursing,University of Arizona,Tucson,AZ 85721-0203,USA

Tai Ji Quan as an exercise modality to prevent and manage cardiovascular disease:A review

Ruth E.Taylor-Piliae

College of Nursing,University of Arizona,Tucson,AZ 85721-0203,USA

Background:Regular exercise is beneficial for adults with cardiovascular disease(CVD)and CVD risk factors.Tai Ji Quan is popular among older adults and may offer additional exercise options.The present article aims to review the scientific literature published with in the past decade on Tai Ji Quan as an exercise modality to prevent and manage CVD.

Methods:An electronic literature search of four databases(PubMed,CINAHL,PsycINFO,and AMED)was conducted from April2003 through March 2013.Studies that examined Tai Ji Quan,were published in English,and specified a targetstudy population of participants with a known CVD condition(e.g.,coronary artery disease,chronic heart failure,or stroke)or studies conducted among participants with a CVD risk factor (e.g.,hypertension,dyslipidemia,or impaired glucose metabolism)were included.

Results:A total of 20 studies met the inclusion criteria:11 randomized clinical trials,seven quasi-experimental studies and two cross-sectional studies.The effect of Tai Ji Quan was examined on more than 20 different study variables among persons with coronary artery disease(n=5 studies),chronic heart failure(n=5 studies),stroke(n=4 studies),and CVD risk factors(n=6 studies).These studies were conducted primarily in Asia(n=9,45%)or the United States(n=8,40%).Overall,participants enrolled in Tai Ji Quan had better outcomes,though m ixed results were reported.

Conclusion:Collectively,these studies indicate that Tai Ji Quan is a safe form of exercise to prevent and manage CVD.Further research is needed with more rigorous study designs,larger sample sizes,adequate Tai Ji Quan exercise doses,and carefully chosen outcome measures that assess the mechanisms as well as the effects of Tai Ji Quan,before widespread recommendations can be made.

CopyrightⒸ2014,Shanghai University of Sport.Production and hosting by Elsevier B.V.All rights reserved.

Cardiovascular disease;Chronic heart failure;Coronary artery disease;Dyslipidemia;Hypertension;Impaired glucose metabolism;Stroke;Tai Ji Quan

1.Introduction

Cardiovascular disease(CVD)is the leading cause of mortality worldwide1and includes several disorders of the heart and blood vessels,such as coronary artery disease, chronic heart failure,and stroke.2In 2008,an estimated 17.3 million people died from CVD,representing 30%of all deaths worldwide.1Of the estimated 83.6 million adults from all genders and races/ethnicities who have one or more type of CVD in the United States,greater than 50%(42.2 million)are 60 years of age and older.2

Additionally,CVD is a leading cause of disabilities in the United States and affects the ability to perform daily self-care activities,such as dressing and bathing;or those necessary for fundamental functioning,such as doing housework or shopping for groceries.2Numerous studies conducted during the past 5 decades have established that regular exercise is beneficial for adult men and women and leads to lower rates of CVD and lower all-cause mortality.3—5

Regular exercise has beneficial effects on many establishedrisk factors for CVD including hypertension, dyslipidemia,and impaired glucose metabolism. For example, it promotesweight reduction, helps reduce hypertension and can improvedyslipidemia by lowering total and low-density lipoproteincholesterol levels and raising high-density lipoproteincholesterol levels. Among persons with impaired glucosemetabolism, regular exercise can aid the ability to use insulinto control blood glucose levels. Although the effect of anexercise program on any single risk factor may generally besmall, the effect of regular exercise on overall CVD risk can bemore pronounced.3—5

Among individuals with CVD, improvements in exercisecapacity and activities that promote balance, muscular strengthand endurance, and flexibility are important to incorporate intoa regular exercise program to reduce disability, aid rehabilitation,and promote recovery from acute cardiovascular events.3—7Even among older adults, appropriate exerciseinterventions can reverse functional limitations and declines inphysical performance that are associated with CVD.3,7Community-based exercise programs suitable for personswith coronary artery disease, chronic heart failure, and strokeare needed to encourage regular participation, particularlyamong adults who have little or no prior exercise experience.8,9

Tai Ji Quan is an appropriate moderate-intensity exercisethat is low-cost, low-tech, low-impact and appeals to adults ofall ages, including older adults with chronic illnesses.10—12Itoffers additional benefits to traditional cardiac and strokerehabilitation programs by combining physical movementswith mental concentration and relaxation.13,14During Tai JiQuan, the slow, rhythmic movements are linked together in acontinuous sequence, while body weight is shifted from leg toleg.15This challenges the balance control system to maintainits center within a changing base of support and enhancesbetter balance, a vital aspect of physical functioning, enablingindividuals to safely perform their usual activities of dailyliving. In addition, individuals are taught to be mindful of whattheir bodies are doing and how it feels while performing Tai JiQuan.15

Tai Ji Quan may offer additional exercise options for personswith CVD following acute cardiovascular events, serve asan adjunct to formal cardiac or stroke rehabilitation programs,become part of a maintenance program for persons with CVD,or act as a means of CVD prevention among persons withCVD risk factors.14,16To date, the majority of Tai Ji Quanresearch studies conducted have examined its effect on physicalperformance measures, such as balance control, amonghealthy community-dwelling adults.17,18Since CVD is theleading cause of mortality worldwide, the objective of thisreview was to assess the scientific literature published withinthe past decade on Tai Ji Quan as an exercise modality toprevent and manage CVD.

2.Methods

An electronic literature search of PubMed was conductedfrom April 2003 through March 2013 using MESH terms “taiji” and “cardiovascular disease”. Additional electronic literaturesearches of CINAHL, PsycINFO, and AMED were conductedfrom April 2003 through March 2013 using searchterms “tai chi” and “cardiovascular disease”. Available humanclinical studies that examined Tai Ji Quan as an exercisemodality, were published in English, and specified a targetstudy population of participants with a known CVD condition(e.g.,coronary artery disease,chronic heart failure,or stroke) or studies conducted among participants with a CVD risk factor(e.g.,hypertension,dyslipidemia,or impaired glucose metabolism)were included.Studies that examined cardiovascular outcomes in healthy individuals were notincluded (e.g.,normal baseline blood pressure).

Abstracts of all research studies were reviewed to determineif participants were assigned to a Tai Ji Quan interventionor if a Tai Ji Quan exercise group was compared withanother group. After eliminating editorials, reviews papers,and duplicate citations, studies were examined in-depth todetermine if they met the inclusion criteria.

3.Results

A total of 20 studies comprising 11 randomized clinicaltrials, seven quasi-experimental studies and two crosssectionalstudies, met the inclusion criteria (Table 1). Therewere a total of 1182 participants (44% women), who ranged inage from 51 to 77 years old. Study sample sizes ranged from18 to 207 participants per study. Tai Ji Quan as an exercisemodality to prevent and manage CVD was examined on avariety of study variables (i.e., more than 20) among personswith coronary artery disease (n=5studies),19—23chronic heart failure(n=5studies),11,24—27stroke(n=4studies),28—31and CVD risk factors(n=6studies).32—39These studies were conducted primarily in Asia (n= 9, 45%)19—22,29,30,36,38,39or the United States (n= 8, 40%).11,23,24,26,27,31—35

Across all studies there were a total of 587 persons enrolledin Tai Ji Quan exercise. The Yang style of Tai Ji Quan was theprincipal style used (75%,n=15),followed by the Wu style (10%,n=2),and combined or unspecified styles(15%,n=3).The Tai Ji Quan interventions ranged from121-h sessions over12weeks29,30to1561-h sessions over52 weeks36,38with participants learning between5and108postures. The main control condition was usual care (n=8),19—22,25,27,31,38followed by other exercise classes,such as stretching,balance training,cardiac rehabilitation exercise, or resistance training(n=5),23,28—30,36sedentary comparisons or wait-list control groups(n=4),32,36,37,39or group-based education(n=3).11,24,26Overall,attrition in these studies was low,and ranged from0to27%:only two studies had attrition rates higher than20%.21,38

3.1.Tai Ji Quan and coronary artery/heart disease

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A total of four quasi-experimental studies and one crosssectional study examined Tai Ji Quan among persons with coronary artery disease(Table1).19—23Study participantsranged in age 60—70 years old,had coronary artery disease confirmed by coronary angiography and/or were attending cardiac rehabilitation.The effects of Tai Ji Quan on CVD risk factors,cardiac health behaviors,autonomic nervous system function,exercise capacity,and physical,cognitive,and psychosocial functioning compared to usual care/cardiac rehabilitation were examined.Overall,participants enrolled in Tai Ji Quan had significantly better outcomes compared to usual care/cardiac rehabilitation.However,of the two studies19,22that examined the effects of Tai Ji Quan on the autonomic nervous system only one found a significant between-group difference.22

3.2.Tai Ji Quan and chronic heart failure

There were four random ized clinical trials11,24,25,27and a secondary analysis of data from one random ized clinical trial26conducted among persons with chronic heart failure(Table 1). Study participants were aged between 59 and 69 years old, with left ventricular ejection fractions between 23%and 35%, and New York Heart Association symptom classes between 1 and 4.The effects of Tai Ji Quan on exercise capacity,quality of life(QoL),serum biomarkers,autonomic nervous system function,mood,sleep stability,psychosocial functioning,and physical activity level compared to usual care or education controls were examined.Following the Tai Ji Quan intervention,participants had significantly better QoL,lower B-type Natriuretic Peptide,better mood and sleep stability,higher exercise self-efficacy,and walked farther compared to those in the control conditions(p＜0.05).There were no significant differences between Tai Ji Quan and control groups on exercise capacity,autonomic nervous system function,and physical activity level.

3.3.Tai Ji Quan and stroke

Four randomized clinical trials examining the effects of Tai Ji Quan compared to other exercise or usual care groups(Table 1)were conducted among stroke survivors.28—31Study participants ranged in age 55—77 years old,with 46%—56% having right-sided hemiparesis,and were on average 27—55 months post-stroke when enrolling in these studies.Outcome variables included balance,gait speed,mobility,QoL,sleep quality,cognitive function,and the safety and feasibility of a Tai Ji Quan intervention.Tai Ji Quan for stroke survivors was reported to be safe and feasible with high study satisfaction, very high intervention adherence,and study retention.31Two studies28,29examined the effects of Tai Ji Quan on balance and reported mixed results,with only one finding a significant between-group difference.29Simiarly,of the two studies28,30that examined the effects of Tai Ji Quan on QoL only one found a significant between-group difference.28There was no significant difference between Tai Ji Quan and the control conditions(balance training,stretching,or resistance training) on gait speed,mobility,sleep quality,or cognitive function.28—30

3.4.Tai Ji Quan and CVD risk factors

A total of two random ized clinical trials,two quasiexperimental studies,one cross-over and one cross-sectional study exam ined Tai Ji Quan use in persons with CVD risk factors(Table 1).32—39Study participants with at least one CVD risk factor(e.g.,hypertension,dyslipidemia,or impaired glucose metabolism)enrolled in these studies and were aged 51—66 years old.Tai Ji Quan as an exercise modality to prevent CVD was examined on a variety of study variables including aerobic endurance or exercise capacity,physical functioning,psychosocial status,blood pressure,lipid profiles, glucose metabolism,body weight or percent body fat,and inflammatory markers.The two randomized clinical trials reported non-significant differences between groups on all study variables,36,37while the quasi-experimental,cross-over and cross-sectional studies reported that those in Tai Ji Quan had improved aerobic endurance/exercise capacity,balance, strength,flexibility,mood,social support,exercise self efficacy,lipid profile and glucose metabolism,and lowered blood pressure,body weight and stress(p＜0.05,includes with in and between group differences).32—35,38,39

4.Discussion

Numerous studies conducted during the past5 decades have clearly established the benefits of regular exercise for adult men and women with CVD and CVD risk factors.3—7Despite the popularity of Tai Ji Quan as an exercise modality among older adults,little research has been conducted in the past decade on the potential benefits of Tai Ji Quan exercise to prevent and manage CVD.16,40,41

Since the phenotype and treatment goals for coronary artery disease,chronic heart failure,stroke,and CVD risk factors are different,the extant Tai Ji Quan research literature involves a variety of study variables,making comparisons across studies difficult.The effect of Tai Ji Quan on aerobic endurance/exercise capacity or QoL was most frequently examined(40%of studies).Overall,participants enrolled in Tai Ji Quan had better outcomes,though m ixed results were reported.

Only 55%of the studies in this review were randomized clinical trials(RCTs).However,all of the studies(n=9) conducted among persons with chronic heart failure and stroke survivors were RCTs,while the other two randomized clinical trials reviewed focused on those with CVD risk factors. Although coronary artery disease is more prevalent than chronic heart failure or stroke,no randomized clinical trials involving Tai Ji Quan in this population were found.2In addition,the majority of studies in this review were likely underpowered to detect statistically significant and/or clinically meaningful differences over time between groups as only 20%of these studies enrolled≥100 participants.Finally,the Tai Ji Quan exercise dose(i.e.,frequency,intensity,time,and type)varied greatly among these studies,and likely affected the reported study outcomes,further limiting generalizability of the reported results.

Collectively,these studies indicate that Tai Ji Quan is a safe form of exercise to prevent and manage CVD.No serious adverse findings were reported,even among these higher risk participants with CVD.It is readily apparent that further research examining the effects of Tai Ji Quan as an exercise modality to preventand manage CVD is needed.Specifically, more rigorous randomized clinical trials with larger sample sizes,adequate Tai Ji Quan exercise dose,and carefully chosen outcome measures are necessary before widespread recommendations can be made.

To date several possible mechanisms by which Tai Ji Quan may prevent and manage CVD conditions or risk factors have been examined.For example,researchers at the University of California-Irvine reported that a short period of Tai Ji Quan increased blood flow(assessed with laser Doppler flow metry) and body energy levels in the form of heat,light,and electrical charge(measured with infrared thermography,single photon counting system and a gas discharge visualization device, respectively).These changes are thought to contribute to overall cardiovascular health by improving the delivery of oxygen and nutrient-rich blood throughout the body and maximizing metabolic by-product removal.42,43In addition, daily practice of Tai Ji Quan may foster brain plasticity or neuron connections,which are especially important for both physiological and psychological recovery among stroke survivors.42—44Continued research exam ining these and other potential mechanisms of Tai Ji Quan’s effect on CVD is recommended.

4.1.Future directions for research and practice

Tai Ji Quan is a multi-component exercise that simultaneously teaches people physical movements and relaxed breathing and focused attention,and is unlike other types of exercise regimes for persons with CVD.16,44As it integrates multiple therapeutic components,it is thought to have synergistic therapeutic effects.44,45For example,falling is a serious public health problem especially among older adults with a chronic illness.46Tai Ji Quan has been reported to reduce the risk of falling47—50and this finding is likely the result of several therapeutic components,including better balance,leg strength,gait,proprioception,neuromuscular control and mindfulness,and less fearof falling.51—55To date,the majority of Tai Ji Quan research studies have used single-factor(e.g., physical function)cause-and-effect reductionist models, though a whole-systems approach may be better suited to this area of scientific inquiry.45Future research should consider using complexity theory to study the effects of Tai Ji Quan on CVD by examining how important cardiovascular factors(e.g., autonomic nervous system function,exercise capacity,QoL, and serum biomarkers)interact with one another in non-linear ways,change over time,or differ among persons with the same CVD condition.

Tai Ji Quan can be readily incorporated into existing cardiac and stroke rehabilitation programs or implemented in community-based settings(e.g.,churches,libraries,senior centers).16,23It is a cost-effective and affordable form of exercise that does not require any special equipment or clothing.Since Tai Ji Quan is generally taught in groups,it is important to first identify an experienced Tai Ji Quan instructor,who is comfortable teaching adults with a chronic illness.In addition,the instructor should be able to accommodate individual health concerns and various levels of prior exercise experience.However,for some persons with CVD, medical clearance from their healthcare provider may be needed before they begin Tai Ji Quan.When beginning a regular program of Tai Ji Quan,one of the shorter forms of Tai Ji Quan is often recommended,especially for those with a chronic illness or who are deconditioned.56

4.2.Limitations

This review has several potential limitations.First,only four electronic databases were searched.Second,the search was restricted to studies publishedwith in the past decade (April 2003 through March 2013)in the English language. Third,the synthesis of the results from these studies was constrained by study heterogeneity,with differences in study design,protocol implementation,Tai Ji Quan style and dose, types of controls,and outcomes assessed.Therefore,the applicability of these results to other settings or broader patient populations must be viewed with caution.Despite these limitations,this review provides a valuable synthesis of the scientific literature published with in the past decade on Tai Ji Quan as an exercise modality to prevent and manage CVD.

5.Conclusion

Given that CVD is the leading cause of mortality worldwide,and in the United States approximately one-third of adults live with one or more types of CVD,the ability to offer additional safe exercise options for this population is important.1,2Tai Ji Quan is a safe exercise modality and may serve as an adjunct to traditional cardiac and stroke rehabilitation programs to manage CVD,orencourage adults with CVD risk factors to begin a regular exercise program to prevent CVD.

Disclosures

The author has no financial disclosure or conflict of interest to report.

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Received 28 June 2013;revised 16 September 2013;accepted 20 September 2013

E-mail address:rtaylor@nursing.arizona.edu.

Peer review under responsibility of Shanghai University of Sport

2095-2546/$-see front matter CopyrightⒸ2014,Shanghai University of Sport.Production and hosting by Elsevier B.V.A ll rights reserved. http://dx.doi.org/10.1016/j.jshs.2013.09.002