Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Does Obesity in Patients with Fibromyalgia Modify Response to Tai Chi Therapy: Analysis of a Randomized Controlled Trial.

Wang1,  Chenchen, Schmid2,  Christopher H., Lee2,  Yoojin, McAlindon1,  Timothy

Tufts Medical Center, Boston, MA
Tufts Medical Center

Purpose:

Fibromyalgia (FM) is a chronic pain disorder of complex etiology. Recent evidence about the association between obesity and FM suggests that this might obfuscate therapy. We evaluated the association of obesity and changes in FM severity, sleep quality and health related quality of life in a randomized controlled trial of FM patients.

Methods:

We studied a sample of 66 eligible individuals (age 21 or older and fulfilled the American College of Rheumatology 1990 diagnostic criteria for FM) who participated in a single-blind, randomized controlled trial. Using computer-generated numbers, we randomly assigned participants to Tai Chi mind-body exercise (Classical Yang style, n=33) or attention control (stretching and wellness education n=33) in three cycles of 22 patients each. The 60-minute group sessions occurred twice-weekly for 12 weeks. We defined obesity as body mass index (BMI) >=30.00 kg/m2. Study endpoints included changes from baseline to 12 weeks in FM Impact Questionnaire (FIQ) score (range, 0 to 100; higher scores indicate more severe symptoms), Pittsburgh Sleep Quality Index (range, 0–21, higher scores indicate worse sleep quality), and Physical Component Summary and Mental Component Summary of the Short Form-36 (SF-36) to assess quality of life (range 0–100; lower scores indicate worse health status). We estimated the relationship between obesity and the treatment effect by the interaction of treatment and obesity in linear regression using each of the three study endpoints.

Results:

The 66 participants had mean age 50y (SD 11.1), mean disease duration 11 y (SD 7.1), mean BMI 33 kg/m2 (SD 8.2), and were mainly female (86%) and white (56%). Thirty-six patients were obese (BMI>=30) and 29 patients were not obese (< 30.00) and 1 had missing BMI. The proportion of obese BMI remained stable in both Tai Chi and control groups. Obese patients assigned to Tai Chi group exhibited significantly greater improvement in FIQ total score (between-group difference -17.5, 95% CI, [-34.1 to -1.0]; P=0.04) than the non-obese group. The SF-36 Physical Component Summary and Mental Component Summary tests also favored obese group but did not reach statistical significance. Both groups improved their sleep quality (Pittsburgh Sleep Quality Index) equally (Table).

Table. Changes in FM severity, sleep quality and health status by BMI group at Week 12*

Variables/ BMI levelGroupsBaseline Mean (SD)At 12 week Mean Change (95% CI)Mean change between Tai Chi vs. control (95% CI) and P-valueMean change between obese vs. non-obese (95% CI) and P-value
BMI >=30 (n=36)Tai Chi38.7 ± (6.9)-0.1 (-0.5, 0.4)0.1 (-0.6, 0.8)-0.3 (-1.3, 0.8),
 Control38.2 (5.4)-0.2 (-0.7, 0.4)P=0.79P=0.62
BMI <30 (n=29)Tai Chi24.7 (3.5)0.2 (-0.4, 0.8)0.4 (-0.4, 1.1) 
 Control25.9 (2.5)-0.2 (-0.6, 0.3)P=0.37 
FIQ (0-100)Tai Chi66.8 (14.4)-32.9 (-40.0, -25.8)-26.3 (-37.2, -15.4)-17.5 (-34.1, -1.0),
BMI >=30 (n=36)Control71.5 (10.3)-6.6 (-14.9, 1.8)P<0.0001P=0.04
FIQ (0-100)Tai Chi56.6 (16.2)-20.6 (-30.2, -10.8)-8.8 (-21.2, 3.6) 
BMI <30 (n=29)Control65.1 (11.0)-11.8 (-19.4, -4.2)P=0.17 
SF-36:PCS (0-100)Tai Chi26.4 (7.2)10.1 (6.7, 13.5)9.0 (3.7, 14.3)4.5 (-3.5, 12.5),
BMI >=30 (n=36)Control26.0 (7.4)1.1 (-2.9, 5.2)P=0.001P=0.27
SF-36:PCS (0-100)Tai Chi31.8 (9.7)6.1 (1.4, 10.8)4.5 (-1.5, 10.5) 
BMI < 30 (n=29)Control29.6 (8.0)1.6 (-2.1, 5.2)P=0.14 
SF-36:MCS (0-100)Tai Chi42.0 (13.3)9.0 (4.3, 13.7)8.7 (1.4, 16.0)5.4 (-5.6, 16.4),
BMI >=30 (n=36)Control35.6 (7.3)0.3 (-5.3, 5.9)P=0.02P=0.34
SF-36:MCS (0-100)Tai Chi43.5 (11.1)6.0 (-0.5, 12.5)3.3 (-4.9, 11.6) 
BMI < 30 (n=29)Control39.1 (12.5)2.7 (-2.4, 7.8)P=0.43 
PSQI (0-21)Tai Chi14.0 (3.0)-3.5 (-5.0, -2.1)-3.3 (-5.5, -1.0)-0.2 (-3.6, 3.2),
BMI >= 30 (n=36)Control14.7 (3.7)-0.3 (-2.0, 1.5)P=0.005P=0.91
PSQI (0-21)Tai Chi13.9 (3.7)-4.2 (-6.2, -2.2)-3.1 (-5.6, -0.5) 
BMI < 30 (n=29)Control12.4 (3.4)-1.1 (-2.7, 0.5)P=0.02 
*N=33 for Tai Chi and Control each group. FIQ = Fibromyalgia Impact Questionnaire. PSQI=Pittsburgh Sleep Quality Index. SF-36: PCS and MCS = Short Form-36 Physical Component Score and Mental Health Summary

Conclusion:

Despite no weight loss in either group, obese patients with FM improved more in their symptoms and quality of life with Tai Chi than with attention control. Tai Chi mind-body exercise may be a particularly beneficial treatment for obese patients with FM. BMI should be considered in future behavioral intervention design.

To cite this abstract, please use the following information:
Wang, Chenchen, Schmid, Christopher H., Lee, Yoojin, McAlindon, Timothy; Does Obesity in Patients with Fibromyalgia Modify Response to Tai Chi Therapy: Analysis of a Randomized Controlled Trial. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :95
DOI: 10.1002/art.27864

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