Effect of T'ai Chi Exercise on Biochemical Profiles and Oxidative Stress Indicators in Obese Patients with Type 2 Diabetes

Abstract

Objective:

This study aimed to validate the effects of a simplified, gentle form of t'ai chi chuan in patients with type 2 diabetes and who are also obese.

Design:

The study was designed to be a randomized controlled trial.

Setting:

This study was conducted in the department of metabolism and endocrinology at Cheng Ching Hospital, in Taichung, Taiwan.

Subjects:

The study subjects were hospital-based patients with type 2 diabetes and who were also obese (ages 40–70, with a body–mass index [BMI] range of 30–35). The patients were randomly selected and grouped into t'ai chi exercise (TCE) and conventional exercise (CE) groups.

Interventions:

After receiving instruction in t'ai chi, the TCE group and the CE group practiced three times per week, including one practice session lasting up to 1 hour, for 12 weeks.

Outcome measures:

Hemoglobin A1C, serum lipid profile, serum malondialdehyde, and C-reactive protein were measured. Physical parameters of body weight and BMI were also measured. Diet and medications of participants were monitored carefully while biochemical and physical conditions were analyzed.

Results:

After 12 weeks, hemoglobin A1C values of the TCE group did not decrease (8.9 ± 2.7% : 8.3 ± 2.2%; p = 0.064). BMI (33.5 ± 4.8 : 31.3 ± 4.2; p = 0.038) and serum lipids, including triglyceride (214 ± 47 mg/dL : 171 ± 34 mg/dL; p = 0.012) and high density lipoprotein cholesterol (38 ± 16 mg/dL : 45 ± 18 mg/dL; p = 0.023) had significant improvements. Serum malondialdehyde tended to decrease from baseline (2.66 ± 0.78 μmol/L : 2.31 ± 0.55 μmol/L; p = 0.035), and C-reactive protein also decreased (0.39 ± 0.19 mg/dL : 0.22 ± 0.15 mg/dL; p = 0.014). No improvements occurred in BMI, lipids, and oxidative stress profiles in the CE group.

Conclusions:

T'ai chi exercise practiced by patients who are obese and have type 2 diabetes is efficient and safe when supervised by professionals and helps improve parameters, such as BMI, lipid profile, C-reactive protein, and malondialdehyde. Periodic monitoring of blood glucose, blood pressure, heart rate, breathing, physical fitness, and symptoms of discomfort of patients who exercise helps prevent injury. Simple, gentle TCE can be applied as regular daily exercise for patients with type 2 diabetes even when such patients are obese.

Introduction

T ype 2 diabetes mellitus, especially when combined with obesity, can lead to many complications associated with impaired metabolism, imbalance of trace elements, and abnormal expression of inflammation.^1,2 Few studies in the literature have addressed the effects of exercise on type 2 diabetes, compared with effects of other nondrug therapies.^3,4 It is also known that exercise requiring strenuous effort increases the cardiorespiratory burden of patients who have diabetes and are obese^5,6 and increases the incidence of hypoglycemia.⁷ Nonetheless, certain exercises, such as moderate stretching or aerobic exercises, will not only enhance cardiorespiratory function and blood circulation, but also promote phagocyte activity,^8
–10 reduce the incidence of respiratory disease and urinary-tract disease, and facilitate management of blood glucose levels and metabolic syndrome efficiently.^11,13 However, it is not easy to determine what kind of exercise is suitable for patients with type 2 diabetes, especially those who are very obese (body–mass index [BMI] ≥ 30–35). In the East, many Chinese martial arts such as t'ai chi chuan emphasize helping the body manage blood glucose levels and enhance cardiorespiratory function. However, these exercises do not have sufficient evidence to prove this claim, especially in patients who are obese, and who, if they have type 2 diabetes, already have cardiovascular, peripheral vascular, or arthritislike symptoms. Wayne et al. described the challenges related to study design to investigate the effects of t'ai chi chuan; this is believed to be the result of the complexity of t'ai chi as a discipline, its multiple components, and the difficulty of distinguishing between specific and nonspecific effects.^14,15 However, other studies have revealed that t'ai chi chuan provides some benefits for the treating patients with certain chronic diseases.^16
–18 Nevertheless, few studies have shown the effects of t'ai chi exercise of different styles when practiced by patients who have diabetes.^19

–22 The present study was designed to study the effects of a gentle form of t'ai chi chuan in patients with type 2 diabetes who were obese. This study utilized a brief form of t'ai chi chuan, called simply t'ai chi exercise (TCE) to evaluate its metabolic and antioxidative effects on these patients. The TCE (Chen-style t'ai chi 13-form) described by Sheng²³ was adapted and simplified from the longer form of Chen-style t'ai chi chuan 99. The simpler, gentler form was developed in 2003 and, since then, has been popularly utilized by adults and older people, because it is convenient and easy to learn.²⁴ The study subjects were divided into TCE group or a CE group. After each group participated in a regular training program for 12 weeks, the effects of t'ai chi and conventional exercises were investigated and assessed in both groups.

Materials and Methods

This was a randomized, controlled trial of the effects of t'ai chi classes versus CE for people with obese type 2 diabetes mellitus. This study was based on patients who have obese type 2 diabetes and who visited the department of metabolism and endocrinology at Cheng Ching Hospital, in Taichung, Taiwan. Patients who had recently undergone serious operations or who had myocardial infarction, stroke, or severe liver or kidney disease were excluded from the study. Subjects were also excluded if they were unable to walk for 10 minutes unaided or to achieve a maximum heart rate (HR) of 65%–75% of normal (220 minus age) or if they were already participating in regular exercise classes three or more times per week. Subjects were eligible and included in the study if they were moderately obese (BMI ≥ 30–35), age ≥ 40 years, had a diagnosis of type 2 diabetes for at least 6 months, had a hemoglobin A1C (HbA1c) above 7%, and were able to attend t'ai chi classes three times per week for 12 weeks.

All included patients were required to maintain their regularly administered hypoglycemic drugs and to follow diet plans. The study was conducted after receiving informed consent from all participants and approval of the institutional review board of Cheng Ching Hospital.

A total of 626 subjects was recruited for this prospective, computer-assisted, randomized controlled study. After first-stage sampling by inclusion criteria and second stage-sampling by written informed consent and then random grouping, 62 patients who were obese and who also had type 2 diabetes were assigned to the TCE group (29 females and 33 males) and 55 patients with the same conditions were assigned to the CE group (25 females and 30 males). Six (6) and 7 patients dropped out of each group, respectively, and, thus, a total of 104 patients completed the study (Fig. 1).

FIG. 1.

Selection steps in the program of exercises for patients with obese type 2 diabetes. 1st sampling: Patients were excluded if they were not obese, unable to walk for 10 minutes unaided, or/and had recently undergone serious operations and/or had myocardial infarctions, brain stroke, or severe liver or kidney diseases. 2nd sampling: Patients were excluded if they were unable to bring their maximum heart rate to 65%–75% of normal (220 minus age) after exercising or if they were already participating in regular exercise classes three or more times per week. DM, diabetes mellitus.

Study method

Both the TCE and CE were trained for at least 12 weeks in basic exercise techniques and diabetes education, and were given instructions for participation in the program. The TCE class was designed by a certified Chen style t'ai chi chuan 99-form instructor. The program was conducted carefully through workshops, and subjects were required to attend one class three times per week for 12 weeks as well as performing exercises at home. None of the subjects in the TCE group had been previously exposed to t'ai chi practices. The TCE²⁴ was adapted and simplified from the longer and more-complicated Chen-style t'ai chi chuan 99-form. The brief form was kept simple, yet incorporated important movements, including “ward-off,” “rollback,” “push,” “press,” “pick,” “row,” “elbow,” “lean,” “advance,” “retreat,” “white crane spreading its wings,” “wave hands like moving cloud,” “fairy spreading flowers,” and so on. Each t'ai chi session consisted of 20 minutes of warm-up exercises, 30 minutes of t'ai chi gymnastics, and 10 minutes of breathing and cool-down training. The warm-up exercises in t'ai chi exercise consisted of low-back and hamstring stretching, gentle calisthenics, and balance training for 20 minutes. The cool-down training consisted of easy breathing, stretches, traction, bending, arm twisting, waist turning, and open-and-close movements. These warm-up and cool-down exercises have previously been shown to have no significant effects on physical or psychologic outcomes.²⁵ Subjects were given a DVD that showed the specific poses to facilitate independent practice.

Subjects in the CE group also attended classes and were engaged mainly in aerobic exercises for 1 hour in each class. A certified exercise instructor directed the CE intervention arm of the study. The conventional exercises consisted of a class three times per week for 12 weeks plus home-based exercises. The conventional sessions consisted of 20 minutes of warm-up exercises, 30 minutes of aerobic dance, and 10 minutes of cool-down exercises. The Hi-Low aerobic dance used in the CE group had been designed and provided for middle-age and older people by the Ministry of Education in Taiwan; this dance included a series of steps: (1) March (walk); (2) Step touch; (3) Touch Step; (4) Out-out, in-in; (5) V-step; (6) Mambo; (7) Box-step; (8) Scoop: and (9) Grapevine. This type of aerobic dance was adapted from the Physical Activity Instruction Handbook published by the Association of Aerobic Exercise, Taiwan, 2001.²⁶ The intensity of the exercise was determined by measurement of subjects' HR and respiration rate before, during, and after the exercise for both the TCE and CE groups. Compliance with the interventions was assessed by having study participants complete daily sheets for each week that recorded whether or not they had exercised or practiced and for how long.

Outcome measures

At the baseline visit, each patient's medical history was reviewed, demographic data were recorded, and fasting blood samples taken for biochemical investigations. Blood was drawn from an antecubital vein at baseline and again at 3 months. The blood was drawn between 7:30 am and 9:00 am, without stasis, and the serum was separated within an hour of collection. On the day of the blood collection, subjects were asked to abstain from TCE or CE. For each subject, basic information was obtained by measuring diagnostic parameters, including examinations of fasting blood glucose, serum lipid profiles, and HbA1c; use of Homeostasis Model Assessment (HOMA), a measure of insulin resistance²⁷; testing for high-sensitivity C-reactive protein (hsCRP), a measure of inflammation²⁸; and and using ankle brachial index (ABI), a measure of peripheral arterial status.²⁹ Oxidative stress was measured by the examining the concentration of malondialdehyde (MDA), phospholipase A2 (PLA2) and protein oxidation (POX).³⁰ The same series of examinations and tests were performed after 3 months of exercise classes.

In this study, the serum and biochemical examinations were done using an analytic instrument (Japan Hitachi 7070) in the same laboratory.

Blood pressure (BP) measurements were conducted by the same person, using the same sphygmomanometer measurements and began with the patient sitting down for 5 minutes. Testing was done to confirm whether the patients had a systolic BP (SBP) ≥ 140 mmHg, whether their diastolic BP (DBP) was ≥ 90 mmHg, and if they were already taking medications.

After each patient had fasted for 8 hours, a blood sample was collected. The sample was then centrifuged within an hour and kept at 20°C. Fasting blood glucose value was determined using a glucose oxidase method (Japan, Hitachi 7070). HbA1C value was determined with high-performance liquid chromatography (HPLC; HLC723G7, Tosoh, Japan). Serum triglyceride (TG) and total cholesterol (TC) were determined with an enzyme-linked immunosorbent (ELISA) (EIA; Japan, Hitachi7070). Serum high-density lipoprotein cholesterol (HDL-C) was tested with dextran SO₄; MgCl₂ was determined by EIA after determining low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). hsCRP was determined using an immuno-turbidometric method (Japan, Hitachi 7070). The interassay coefficient of variation was 5%. MDA, PLA2, and POX concentrations in the serum were measured spectrophotometrically according to Yagi.³⁰

All patients accepted and received two-dimensional (2-D) ultrasound measurement of blood-vessel pressure and blood-flow velocity to estimate data including ABI. An ABI less than 90% suggests abnormal vessels of the peripheral arterial blood circulatory system. The measurements were checked by the same ultrasonic-wave machine (Japan, Aloka) with the same technician operating the equipment.

Sample size

The basic information gathered from the patients was examined and recorded by the same qualified health education personnel. The sample size was estimated based on studies of aerobic and resistance-training effects on HbA1c in type 2 diabetes, as this was the primary outcome of the current study. A decrease in HbA1c of 1% and a standard deviation (SD) of 1% was estimated. Setting the power at 0.8 and an α value of 0.05, the total sample size required was estimated to be 34.³¹ We estimated a dropout rate of 15%, thus, the sample size was increased to 39. This sample size was determined to be large enough to test for outcomes.

Statistical analysis

Analyses were performed with statistical software (SPSS, version 12.0). The differences before and after the study were analyzed by using paired Student's t-tests. To investigate the effects of a variable within a group, within-subjects factors analysis was used. To investigate the effects of a variable between groups, between-subjects analysis and two-way analysis of variance (ANOVA) tests with a 95% confidence interval (CI) were used. Two-way ANOVA was applied to detect differences between groups (TCE and CE) and within groups over the duration of treatment. A p-value ≤ 0.05 was considered to be statistically significant.

Results

Baseline data

Initially, 155 subjects of the 626 that had been recruited were selected by our screening process. Twenty-eight (28) subjects were unable to attend the classes at the times scheduled because of work or because they were already taking part in other regular exercise classes, and 10 patients were excluded for other reasons. Another 13 subjects dropped out after classes started because they had mild muscular pain or other nonspecific complaints or individual reasons, leaving a final number of 104 subjects who would remain in the study. After randomized screening by a centralized computer-generated allocation method, 31 male and 25 female patients (n = 56) were assigned to the TCE group, with an average age of 59.1 ± 6.2 years. In addition, 28 male and 20 female patients (n = 48) were assigned to the CE group, with an average age of 57.4 years. All participants were of Chinese descent. Their characteristics are listed in Table 1. No significant differences were found between these two groups.

Table 1.

Characteristics T'ai Chi Exercise (TCE) and Conventional Exercise (CE) Groups

	CE group n = 48	TCE group n = 56	p-Value
Age (years)	57.4 ± 5.8	59.1 ± 6.2	0.332
Gender (female/male)	28/20	31/25	0.116
Duration (years)	7.8 ± 3.1	8.5 ± 3.5	0.080
BMI (kgw/m²)	33.2 ± 4.1	33.5 ± 4.7	0.225
Fasting blood glucose (mg/dL)	182.4 ± 28.2	185.6 ± 25.3	0.148
HbA1c (%)	8.8 ± 3.6	8.9 ± 2.7	0.366
Triglyceride (mg/dL)	208 ± 49.3	214 ± 47	0.183
Cholesterol total (mg/dL)	189 ± 32	194 ± 33	0.410
HDL-cholesterol (mg/dL)	40 ± 14.5	38 ± 16	0.331
Uric acid (mg/dL)	7.1 ± 2.7	6.9 ± 2.5	0.367
ALT (U)	33 ± 18	31 ± 15	0.175
Creatinine (mg/dl)	1.1 ± 0.6	1.2 ± 0.6	0.289
HOMA	7.6 ± 8.6	7.9 ± 7.6	0.191
HsCRP (ng/dl)	0.35 ± 0.22	0.39 ± 0.19	0.152
ABI (%)	91.8 ± 4.9	91.5 ± 4.6	0.094

Data are mean ± standard deviation; p-values were analyzed by Student's paired t-test.

BMI; body–mass index; HDL, high-density lipoprotein; ALT, alanine transferase; HOMA, Homeostasis Model Assessment; CRP, C-reactive protein, ABI, ankle brachial index.

Outcome measures

After 12 weeks, a comparison of measurements of the TCE group before and after the program showed that there were no improvements in HgbA1C (8.9 ± 2.7% : 8.3 ± 2.2%; p = 0.064), but BMI (33.5 ± 4.8 : 31.3 ± 4.2; p = 0.038), serum TG (214 ± 47 mg/dL : 171 ± 34 mg/dL; p = 0.012), serum HDL-C (38 ± 16 mg/dL : 45 ± 18 mg/dL; p = 0.023), and hsCRP (0.39 ± 0.19 mg/dL : 0.22 ± 0.15 mg/dL, p = 0.014) improved significantly. ABI did not change significantly after this training course (91.5 ± 4.6% : 92.3 ± 4.8%; p = 0.071). However, measurements of the CE group before and after the exercise program showed that there were no improvements in HgbA1C (8.8 ± 3.6% : 8.7 ± 2.3%; p = 0.55) and no improvements in BMI (33.2 ± 4.1 : 32.8 ± 4.4; p = 0.241), serum TG (208 ± 49.3 mg/dL : 189 ± 38.5 mg/dL; p = 0.14), serum HDL-C (40 ± 14.5 mg/dL : 41.3 ± 17.6 mg/dL; p = 0.211), hsCRP (0.35 ± 0.22 mg/dL : 0.32 ± 0.19 mg/dL; p = 0.138) and ABI (91.8 ± 4.9% : 92.3 ± 5.2%; p = 0.302). See Table 2.

Table 2.

Comparisons Between the T'ai Chi Exercise Group (TCE) and Conventional Exercise Group (CE)

	CE group		TCE group
Item	Before treatment (n = 48)	After treatment (n = 44)	Before treatment (n = 56)	After treatment (n = 50)	p-Value
BMI (kgw/m²)	33.2 ± 4.1	32.8 ± 4.4	33.5 ± 4.8	31.3 ± 4.2	0.017^*
Fasting blood glucose (mg/dL)	182.4 ± 28.2	178.6 ± 30.1	185.6 ± 25.3	179.2 ± 22.4	0.083
HbA1c (%)	8.8 ± 3.6	8.5 ± 2.3	8.9 ± 2.7%	8.3 ± 2.2	0.155
TG (mg/dL)	208 ± 49.3	189 ± 38.5	214 ± 47	171 ± 34	0.021^*
TC (mg/dL)	189 ± 32	186.2 ± 40	194 ± 33	189 ± 31.5	0.184
HDL-C (mg/dL)	40 ± 14.5	41.3 ± 17.6	38 ± 16	45 ± 18	0.043^*
Uric acid (mg/dL)	7.1 ± 2.7	7.0 ± 3.3	6.9 ± 2.5	6.7 ± 2.4	0.258
ALT (U)	33 ± 18	29.7 ± 19.4	31 ± 15	28.3 ± 15.6	0.064
Creatinine (mg/dL)	1.1 ± 0.6	1.09 ± 0.5	1.2 ± 0.6	1.3 ± 0.6	0.357
HOMA	7.6 ± 8.6	7.8 ± 6.9	7.9 ± 7.6	8.1 ± 7.9	0.448
HsCRP(ng/dL)	0.35 ± 0.22	0.29 ± 0.18	0.39 ± 0.19	0.27 ± 0.13	0.021^*
ABI (%)	91.8 ± 4.9	92.3 ± 5.2	91.5 ± 4.6	92.2 ± 4.8	0.055

Data are mean ± standard deviation; p-values were analyzed using two-way analysis of variance tests.

p < 0.05.

BMI, body–mass index; TG, triglyceride; TC, total cholesterol; ALT, alanine transferase; HOMA, Homeostasis Model Assessment; ABI, ankle brachial index.

The results between the TCE and CE groups showed no differences in HgbA1C (−0.2 ± 0.9% : −0.1 ± 0.3%; p = 0.155), and no differences emerged from the HOMA study (0.3 ± 0.6 : 0.4 ± 0.4; p = 0.448). However, there were significant differences in BMI between groups (−2.2 ± 4.4 : −0.4 ± 4.2; p = 0.017) and significant differences in lipid profiles of the two groups, including TG (−28.3 ± 17.4 mg/dL : −10.2 ± 9.6 mg/dL; p = 0.021) and HDL-C (5.5 ± 2.3 mg/dL : 3.1 ± 2.4 mg/dL; p = 0.043). hsCRP also tended to decrease more in the TCE group (−0.18 ± 0.06 : −0.04 ± 0.03; p = 0.02) than in the CE group. Although differences were noted in ABI between groups, these differences were not significant (0.8 ± 0.6% : 0.5 ± 0.4%; p = 0.055). See Table 2.

After 3 months of exercise classes, MDA, the oxidative stress indicator, was decreased in the TCE group (2.53 ± 0.72 μmol/L : 2.22 ± 0.61 μmol/L; p = 0.025); however, this effect was not found in the CE group (2.43 ± 0.54 μmol/L : 2.38 ± 0.42 μmol/L; p = 0.117). No significant changes in the other indicators, PLA2 and POX, were found either group (Fig. 2).

FIG. 2.

Comparing the oxidative stress indicators malondialdehyde (MDA), phospholipase A2 (PLA2) and protein oxidation (POX) between conventional exercise and t'ai chi exercise groups in patients with obese type 2 diabetes over a 3-month period.

Discussion

Several studies have considered the importance of regular exercise in facilitating improvements in metabolic and immune functions.^33

–36 However, evidence regarding the correlation between improvements in obesity or cardiorespiratory-disease–related inflammatory markers (such as hsCRP), oxidative stress indicators (such as MDA), and moderate stretching exercises are insufficient. Gordon et al.¹³ explored yoga as a way to improve blood glucose, serum lipids, and oxidative stress in a population with diabetes. That study was somehow similar to ours despite the fact that it used yoga. Yoga, as we know, is an ancient practice that has become a popular way to engage in stretching exercise, breathing, and movement (hatha yoga) around the world, but yoga requires a clean and smooth ground surface (floor), most often in an indoor space, and involves many floor postures. T'ai chi was chosen because to obviate these concerns and because it is more acceptable and popular in our city. Although t'ai chi obviously cannot reduce blood glucose levels, it can help decrease weight and inflammation index of a patient. Wayne and Kaptchuk^14,15 primarily described the difficulty of t'ai chi research because of the multicomponent nature and complexity of t'ai chi and also because its specific and nonspecific effects are hard to distinguish. However, because it is also diversified, inclusive, and mystical, this study was designed to study and explore t'ai chi's efficacy using a scientific approach. As Song et al.¹⁹ showed, t'ai chi can be an alternative exercise intervention for increasing glucose control, diabetic self-care activities, and quality of life (QoL). Wang et al.²⁰ described an 8-week t'ai chi intervention that had beneficial effects on blood glucose, high- and low-affinity insulin receptor numbers (r1, r2), and their binding capacity (R1, R2) in patients with type 2 diabetes. However, other studies such as that of Tsang et al.²¹ showed that some t'ai chi forms, although developed specifically for diabetes, may not have been of sufficient intensity, frequency, or duration to effect positive changes in many aspects of physiology or health status relevant to older people with diabetes.

The current study is the first local hospital-based, randomized controlled trial to assess the effectiveness of t'ai chi exercise for patients who have obese type 2 diabetes. After practicing the custom designed TCE program for 3 months, regardless of whether patients were compared from baseline to the end of the study or compared with patients in the CE group, and regardless of the fact that the exercise could not improve blood glucose control, it seemed that TCE was able to decrease many lipid levels in the profiles and inflammatory markers, including hsCRP and oxidative stress indicators, such as MDA. As in other studies,^16,22 the lipoprotein-lipid profiles were improved by TCE, including reductions in TG and TC. Furthermore, a decrease in LDL-C and an increase in HDL-C were found following the TCE intervention.

Patients with diabetes, especially when this condition is associated with obesity, have higher serum levels of inflammatory and oxidative stress markers such as hsCRP and MDA.³⁷ Oxidative stress plays an important role in the formation of vascular complications in diabetes.³⁸ In patients with diabetes or obesity, there is overproduction of reactive oxygen radicals (reactive oxygen species [ROS]) and also, at the same time, decreased efficiency of antioxidant defense systems.³⁹ In particular, the present study showed that TCE can also decrease serum hsCRP and MDA levels to reduce the risk of some oxidative and arteriosclerotic complications.

People with peripheral arterial disease (PAD) have significantly increased all-cause and cardiovascular mortality rates, compared to persons without PAD.⁴⁰ Among persons with PAD, lower ankle brachial index (ABI) values are associated with increased mortality compared to higher ABI values.⁴¹ Lower ABI is not only a hallmark of PAD, but also that of cardiovascular mortality and poor QoL. A previous study demonstrated that supervised walking or moderate stretching exercise programs improved 6-minute walk performance in persons with PAD and intermittent claudication.⁴² The TCE program in the current study seemed to match the requirements for reducing PAD in these patients who had obese type 2 diabetes, although this effect was not obvious, perhaps because the shorter duration of this study.

In addition, previous studies have revealed that certain physical activities such as t'ai chi chuan can reduce insulin resistance,^43,44 promote blood circulation,⁴⁵ and reduce the functions of blood coagulation factors.⁴⁶ In the current study, through ongoing and regular practice of TCE, the physical condition and metabolic rate of the subjects may have been enhanced. However, the results of the insulin-resistance study (HOMA) did not show any significant improvements among participants in this study. This might be the result of the effects of aging or insufficient follow-up in the program.

Of course, most of these improvements can be achieved by strict diet control or adding dosages of medicines, such as oral antidiabetes agents, or insulin injections. The short-term effects of taking larger doses of medicine and strict diet control are even faster and perhaps better than healthy gymnastics,⁴⁷ but it is very hard to attribute long-term effects to taking medication and modifying diets. In addition, whether or not there are risks of any other side-effects needs to be considered, including possible increases in body weight associated with certain antidiabetes agents or insulin. In contrast, under a well-designed program and after a simple warm-up and professional instruction, an individual can practice TCEs step-by-step and slowly by themselves. After 1 hour, an individual can burn approximately 300–400 calories. That energy consumption is compatible with a moderate degree of physical activity.⁴⁸

After 12 weeks of practice, a few participants (13) dropped out of this program because they experienced mild muscular pain or had other nonspecific complaints or individual reasons. Comparing the data before and after the program and with the CE group, the TCE exercise showed that TCE can truly help decrease lipid and oxidative levels and thus prevent cardiovascular risks in patients who have diabetes comorbid with obesity. Why did these two exercises produce differences? Both groups practiced exercises of moderate intensity so that the calories consumed in both groups should have been basically similar. However, the key benefits of TCE are not actually in consumed calories but in the efficacy of enhanced metabolism, cardiopulmonary function, and antioxidation and antiinflammation activation.

Give that significant improvement was found in the TCE group, it would be inappropriate for such patients perform ordinary and conventional exercise. Based on this study's results, more patients with diabetes should be encouraged to start TCE. The concept is similar what happens when a new, effective drug is available: The old and ineffective one should be eliminated so that treatment timing with the new agent will not be delayed. Such fair and humane concerns must be upheld for patients with respect to TCE as well.

This study had several limitations. The first was the absence of a nonexercising control group. Second, plasma variables were not measured at the beginning of the 6-week dietary stabilization period, so there is the possibility that the changes in biochemical data seen were influenced by the change in diet prior to beginning the exercise intervention. More follow-up time must also be included in future trials to keep track of these patients as well as any participants in such studies. Perhaps such exercises can also be used as training for other high-risk patients, including those who are prediabetic or who have metabolic syndrome or cardiovascular disease.

Conclusions

Basically, it was observed that TCE practiced by patients with obese type 2 diabetes is efficient and safe when supervised by professionals. Every class started with warm-ups and ended with cool-down exercises to prevent sport injuries. In addition, in previous studies and this current pilot study, very few adverse reactions or injuries were reported. While this study was being conducted, blood sugar, BP; HR, breathing, physical fitness, and symptoms of discomfort in participants were all monitored periodically. Thus, it can be concluded that this simple and newly designed physical activity, the gentle short-form TCE, can be applied as a regular form of daily exercise for patiens with type 2 diabetes patients even those who have obesity.

Footnotes

Acknowledgments

This study was supported by the Diabetic Research Fund, Diabetic Research Project 1011-2, department of internal medicine, Cheng Ching Hospital. The authors wish to express their sincere gratitude to the headmaster Mr. Liao of the Taichung Diabetes Consideration Association and t'ai chi chuan teacher Mr. Xie Ming Shan for their instructions and cooperation in this investigation.

Disclosure Statement

This study was funded by the Diabetic Research Fund of Cheng Ching Hospital, Taichung, Taiwan. The authors have no competing financial interests and no disclosures to report.

References

Toutouzas

, Markou

, Drakopoulou

et al. Increased heat generation from atherosclerotic plaques in patients with type 2 diabetes: An increased local inflammatory activation. Diabetes Care, 2005; 28:1656–1661.

Tan

, Chow

, Tam

et al. Association between acute-phase reactants and advanced glycation end products in type 2 diabetes. Diabetes Care, 2004; 27:223–228.

Nielsen

, Hafdahl

, Conn

et al. Meta-analysis of the effect of exercise interventions on fitness outcomes among adults with type 1 and type 2 diabetes. Diabetes Res Clin Pract, 2006; 74:111–120.

Stewart

. Role of exercise training on cardiovascular disease in persons who have type 2 diabetes and hypertension. Cardiol Clin, 2004; 22:569–86.

Bruunsgaard

. Physical activity and modulation of systemic low-level inflammation. J Leukoc Biol, 2005; 78:819–835.

Peterson

, Pederson

. The anti-inflammatory effect of exercise. J Appl Physiol, 2005; 98:1154–1162.

Suzuki

, Nakaji

, Yamada

et al. Impact of a competitive marathon race on systemic cytokine and neutrophil responses. Med Sci Sports Exerc, 2003; 35:348–55.

Suzuki

, Nakaji

, Yamada

et al. Systemic inflammatory response to exhaustive exercise: Cytokine kinetics. Exerc Immunol Rev, 2002; 8:6–48.

Nieman

. Current perspective on exercise immunology. Curr Sports Med Rep, 2003; 2:239–242.

10.

Meneilly

, Tessier

. Diabetes in the elderly. Diabet Med, 1995; 12:949–960.

11.

Shore

, Shinkai

, Rhind

, Shephard

. Immune responses to training: How critical is training volume? J Sports Med Phys Fitness, 1999; 39:1–11.

12.

Davis

, Murphy

, Brown

et al. Effects of moderate exercise and oat beta-glucan on innate immune function and susceptibility to respiratory infection. Am J Physiol Regul Integr Comp Physiol, 2004; 286:R366–R372.

13.

Gordon

, Morrison

, McGrowder

et al. Effect of exercise therapy on lipid profile and oxidative stress indicators in patients with type 2 diabetes. BMC Complement Altern Med, 2008; 8,21:21–30.

14.

Wayne

, Kaptchuk

. Challenges inherent to t'ai chi research: Part I—t'ai chi as a complex multicomponent intervention. J Altern Complement Med, 2008; 14:95–102.

15.

Wayne

, Kaptchuk

. Challenges Inherent to t'ai chi research: Part II—defining the intervention and optimal study design. J Altern Complement Med, 2008; 14:191–197.

16.

Wang

, Collet

, Lau

. The effect of TCC exercise on health outcomes in patients with chronic conditions: A systematic review. Arch Intern Med, 2004; 164:493–501.

17.

, Kuo

. The effect of tai chi chuan on the autonomic nervous modulation in older persons. Med Sci Sports Exerc, 2003; 35:1972–1976.

18.

Tsang

, Hui-Chan

. Effect of 4- and 8-wk intensive tai chi training on balance control in the elderly. Med Sci Sports Exerc, 2004; 36:648–657.

19.

Song

, Ahn

, Roberts

et al. Adhering to a t'ai chi program to improve glucose control and quality of life for individuals with type 2 diabetes. J Altern Complement Med., 2009; 15:627–632.

20.

Wang

. Effects of tai chi exercise on patients with type 2 diabetes. Med Sport Sci, 2008; 52:230–238.

21.

Tsang

, Orr

, Lam

et al. Health benefits of tai chi for older patients with type 2 diabetes: The “Move It for Diabetes study”—a randomized controlled trial. Clin Interv Aging, 2007; 2:429–439.

22.

Zhang

, Fu

. Effects of 14-week tai ji quan exercise on metabolic control in women with type 2 diabetes. Am J Chin Med, 2008; 36:647–654.

23.

Sheng

. Chen Style Tai Chi Chuan 5 Pattern and 13 Form. Taipei, Taiwan: Da Zhan Publishing, 2004.

24.

De Sheng

. Simplified Chen Style Tai Chi Chuan 13 Form. Taiwan: Shi Mao Publishing Corporation, 1994.

25.

Nieman

, Miller

, Henson

et al. Effects of high- vs moderate-intensity exercise on natural killer cell activity. Med Sci Sports Exerc, 1993; 25:1126–1134.

26.

Association of Aerobic Exercise. Physical Activity Instruction Handbook. Taipei, Taiwan: Association of Aerobic Exercise, 2001.

27.

Katz

, Nambi

, Mather

et al. Quantitative insulin sensitivity check index: A simple, accurate method for assessing insulin sensitivity in humans. J Clin Endocrinol Metab, 2000; 85:2402–2410.

28.

Koenig

, Sund

, Frohlich

et al. C-Reactive protein, a sensitive marker of inflammation, predicts future risk of coronary heart disease in initially healthy middle-aged men: Results from the MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) Augsburg Cohort Study, 1984 to 1992. Circulation, 1999; 99:237–242.

29.

Doobay

, Anand

. Sensitivity and specificity of the ankle-brachial index to predict future cardiovascular outcomes: A systematic review. Arterioscler Thromb Vasc Biol, 2005; 25:1463–1469.

30.

Yagi

. Lipid peroxide and human diseases. Chem Phys Lipids, 1987; 45:337–351.

31.

Tam

, Lau

, Tsang

et al. Epidemiological study of diabetic retinopathy in a primary care setting in Hong Kong. Hong Kong Med J, 2005; 11:438–444.

32.

Cheng

. The kung chia of T'ai Chi Chuan. Cheng

. Tai Chi Chuan: A Simplified Method of Calisthenics for Health and Self Defense. Berkeley, CA: North Atlantic Books, 1981; 32–111.

33.

Woods

, Lowder

, Keylock

. Can exercise training improve immune function in the aged? Ann N Y Acad Sci, 2002; 959:117–127.

34.

Fritz

, Kramer

, Karlsson

et al. Low-intensity exercise increases skeletal muscle protein expression of PPARdelta and UCP3 in type 2 diabetic patients. Diabetes Metab Res, 2006; 22:492–498.

35.

Ratner

. The Diabetes Prevention Program Research: An update on the diabetes prevention program. Endocr Pract, 2006; suppl1:20–24.

36.

Boule

, Kenny

, Haddad

et al. Meta-analysis of the effect of structured exercise training on cardiorespiratory fitness in type 2 diabetes mellitus. Diabetologia, 2003; 46:1071–1081.

37.

Van den Steen

, Rudd

, Dwek

et al. Cytokine and protease glycosylation as a regulatory mechanism in inflammation and autoimmunity. Adv Exp Med Biol, 1998; 435:133–143.

38.

Brownlee

. Biochemistry and molecular cell biology of diabetic complications. Nature, 2001; 414:813–820.

39.

Laight

, Carrier

, Ánggård

. Antioxidants, diabetes and endothelial dysfunction. Cardiovasc Res, 2000; 47:457–464.

40.

Heald

, Fowkes

, Murray

et al. Ankle–brachial index collaboration: Risk of mortality and cardiovascular disease associated with the ankle–brachial index. Systematic review. Atherosclerosis, 2006; 189:61–69.

41.

Sikkink

, van Asten

, van't Hof

et al. Decreased ankle/brachial indices in relation to morbidity and mortality in patients with peripheral arterial disease. Vasc Med, 1997; 2:169–173.

42.

Gardner

, Katzel

, Sorkin

et al. Exercise rehabilitation improves functional outcomes and peripheral circulation in patients with intermittent claudication: A randomized controlled trial. J Am Geriatr Soc, 2001; 49:755–62.

43.

Dunstan

, Daly

, Owen

et al. High-intensity resistance training improves glycemic control in older patients with type 2 diabetes. Diabetes Care, 2002; 25:1729–1736.

44.

Sigal

, Kenny

, Wasserman

et al. Physical activity/exercise and type 2 diabetes. Diabetes Care, 2004; 27:2518–2539.

45.

Braith

, Stewart

. Resistance exercise training: Its role in the prevention of cardiovascular disease. Circulation, 2006; 113:2642–2650.

46.

Harper

, Ferreira

, Lutjemeier

et al. Human femoral artery and estimated muscle capillary blood flow kinetics following the onset of exercise. Exp Physiol, 2006; 91:661–671.

47.

Knowler

et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. NEMJ, 2002; 346:393–403.

48.

Ainsworth

. Compendium of physical activities: An update of activity codes and MET intensities. Med Sci Sports Exerc, 2000; 32:S498–S504.