Although the obesity rate has been steadily increasing since the 1960s, with 1 in 3 adults currently classified as obese in the United States, Maria M. Wertli, MD, PhD, Research Fellow, Horten Centre for Patient Oriented Research and Knowledge Transfer, Department of Internal Medicine, University of Zurich, Switzerland, and colleagues assert that the impact of being overweight and obese on the working population is yet to be wholly realized. In a recent study published in BMC Musculoskeletal Disorders, they reported that being overweight or obese is associated with higher levels of disability before treatment in patients with low back pain (LBP). This trend was not observed in patients with neck pain (NP), they noted.
Dr Wertli and colleagues conducted a cross-sectional study examining the influence of body weight on disability in patients with spinal pain. In particular, they assessed baseline factors, and longitudinal examination of data from an outpatient physical therapy registry spanning from June 2010 to December 2012.
Assessing Patients with NP and LBP
A total of 739 patients, including 548 patients with LBP and 191 with NP, qualified for study inclusion; 211 patients with LBP and 71 with NP completed treatment, an end-of-treatment questionnaire, and were included in a longitudinal analysis.
All patients completed questionnaires prior to, during, and when discharged from treatment. Patients with NP and LBP were treated with an evidence-based care approach, including 4 to 8 weeks of active physical therapy and spine education, all provided by specially trained physical therapists at the spine clinic twice weekly for 1 hour. Treatment was discontinued when no longer necessary, coverage by the insurance companies stopped, the patient chose not to pursue treatment, or when the patient was noncompliant with the therapist recommendations.
Patient-reported disability was the primary outcome measure of the study, and was assessed per the Oswestry Disability Index (ODI) and Neck Disability Index (NDI) for patients with LBP and NP, respectively. A meaningful clinically important difference (MCID) in the ODI or NDI (ie, a change of 30%) was the basis for the longitudinal analysis.
Disability, Lower ODI Scores More Common with LBP
According to the results of the cross-sectional analysis, obese patients with LBP reported more disability compared with lean patients (body mass index [BMI], 18-<25 kg/m2). In addition, lower education was also associated with more disability. In the group of patients with NP, Dr Wertli and colleagues found that no BMI categories had any significant influence on baseline disability; however, baseline pain and high fear of physical activities were associated with more disability.
Data from the longitudinal analysis indicated that overweight patients with LBP had a greater decrease in ODI scores at the end of treatment, compared with lean patients. Patients in obesity class II to III (≥35 kg/m2) however, had less reduction in disability following treatment assessment. The authors noted that the probability of an MCID in ODI from baseline to the end of treatment did not differ between patients in the varying BMI categories. For patients with NP, NDI values decreased similarly among all groups; no clinically meaningful change in NDI was observed between the BMI subgroups and the lean patients.
“Our findings suggest that severe obesity might require specific guidance and that severely obese patients might experience more disability associated with LBP when compared to lean and overweight patients,” the study authors concluded. “When not considered, this might lead to a negative feedback for the patient and lead to early termination of physical therapy in these patients and worse outcomes, including chronic, disabling pain.”
Further research is needed to address the impact of severe obesity on recovery in patients with LBP. Treatment strategies that combine weight management, cardiovascular fitness, physical limitations, and LBP rehabilitation should also be evaluated.
- Wertli MM, Held U, Campello M, Weiner SS. Obesity is associated with more disability at presentation and after treatment in low back pain but not in neck pain: findings from the OIOC registry. BMC Musculoskelet Disord. 2016;17:140.