Study Design. A retrospective multicenter study.
Objective. To investigate the relationship between body mass index (BMI) and changes in pain and disability resulting from exercise-based chronic low back pain (cLBP) treatment.
Summary of Background Data. Past research has shown evidence of a relationship between BMI, a measurement of obesity, and cLBP. Exercise is a known beneficial treatment for cLBP. However, it is unclear if exercise-induced changes in pain and disability are related to baseline levels of, or changes in, BMI.
Methods. One hundred and twenty-eight (n = 128) males and females with cLBP performed 8 weeks of exercise, consisting of 3 to 5 exercise sessions (minimum of 1 supervised session) per week. Outcome measures included BMI and self-reported pain and disability. BMI was calculated as weight divided by height squared (kg/m2). Pain was measured using the visual analogue scale and disability was measured using the Oswestry Disability Index. Correlation, regression, covariance and likelihood ratios analyses were used to examine the relationship between BMI and self-reported pain and disability changes.
Results. No baseline relationships between BMI and self-reported pain (r = −0.083, P = 0.349) and disability (r = 0.090, P = 0.314) were observed. There was no relationship observed between baseline BMI (P = 0.938, P = 0.873), or changes in BMI (P = 0.402, P = 0.854), with exercise-related changes in pain and disability, respectively. No relationships between baseline BMI or BMI changes with pain and disability at baseline or after exercise were observed on the basis of pain and disability subgroups. BMI was not a predictor of exercise-based pain and disability changes.
Conclusion. There was no significant relationship between BMI and self-reported pain and disability in cLBP participants. BMI was not a predictor of exercise-induced changes in pain and disability. The reliance on BMI as a sole measurement of obesity in cLBP research may be unwarranted.
Level of Evidence: 2
No research on the body mass index-chronic low back pain (BMI-cLBP) relationship after exercise currently exists. The relationship between BMI and self-reported pain and disability changes after exercise was investigated. BMI was not related to pain and disability at baseline or after exercise and did not predict exercise-induced pain and disability changes in individuals with cLBP.
From the School of Science and Health, University of Western Sydney, New South Wales; Australia.
Address correspondence and reprint requests to Cristy Brooks, BHSci, School of Science and Health, Building 20.G.35, Campbelltown Campus, University of Western Sydney, Locked Bag 1797, Penrith South, New South Wales, 2751, Australia; E-mail: firstname.lastname@example.org
Acknowledgment date: May 8, 2013. First revision date: July 30, 2013. Acceptance date: August 24, 2013.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
No relevant financial activities outside the submitted work.