Body Weight and Musculoskeletal Pain  

Overview:

Weight reduction and regular exercises are recommended non-pharmacological treatments for osteoarthritis and musculoskeletal diseases. It is unclear whether individuals with musculoskeletal diseases should exclusively aim for normal weight. There could be another cut-off to consider musculoskeletal diseases, as well as overall wellbeing and compliance to weight reduction/exercise. Physical activity/inactivity influences the body’s fat, muscle and bone mass, and knowledge of the mechanism of these components on musculoskeletal pain in humans is poor. The impact of increased body weight on the musculoskeletal system is likely to be loading. It could also be that active molecular products of the accumulated fat tissue reduce healing and increase the chance of musculoskeletal diseases, though muscle tissue could have a preventive role.  

This project will explore how body weight affects single and multi-site musculoskeletal pain over a long period, as well as how the history of musculoskeletal pain impacts body weight. We will consider body composition and metabolic change effects on musculoskeletal diseases. Given the paucity of research on spine and back pain, there will be some focus on these. The project outcomes should provide background for more tailored guidelines for weight reduction and exercises in musculoskeletal diseases. 

Aims and Objectives:

• Provide evidence on how to tailor weight management and exercises to individuals with musculoskeletal pain in general and specifically with back pain. 

• Provide risk estimates for recurrence of episodic musculoskeletal pain, accounting for age and body mass index in high-quality, longitudinal, population-based English cohorts.  

• Investigate patterns of body mass index over two decades and explore mutual influence between musculoskeletal pain and body mass index patterns, and provide body mass index cut-off for musculoskeletal diseases. 

• Explore definitions of spine osteoarthritis and its relation to back pain analogous to knee osteoarthritis and knee pain. 

• Investigate the mechanism of body weight and its components on back pain considering direct mechanical and indirect effects via inflammatory and metabolic parameters. 

• Investigate metabolic dysregulation clustered in metabolic syndrome and spine osteoarthritis and back pain. 

Key Findings:

We found that women with body mass index 27-34 were most likely to experience musculoskeletal pain and these patterns, capturing the increase overweight-to-obese, were mutually related to musculoskeletal pain, i.e., knee and multi-site pain contributed to becoming obese, and trajectories of becoming obese increased the odds of experiencing pain later. 

Slightly overweight women (body mass index 25-27), had no different risk of musculoskeletal pain or mortality than normal-weighted women. The body mass index of 27 could be an initial goal for weight reduction concerning musculoskeletal pain, and it might increase patients’ motivation, engagement, and compliance for achieving an easier target while ensuring overall wellbeing. 

We found that spinal structural changes and their severity detected on lumbar radiographs provide limited value for decision-making regarding back pain management and back pain as the treatable outcome should be considered overall. 

The higher the body weight, due to either obesity or body height, the higher chance of experiencing back pain episodes. The effects of body weight and fat mass on back pain episodes are predominantly through loading, unlikely indirectly through inflammatory or metabolic parameters. Our results suggest that weight reduction could decrease the short- and long-term obesity-related effects on back pain episodes. However, the height-related body weight effects should be kept in mind when developing and delivering prevention programmes. 

Outputs:

• Perera RS, Chen L, Hart DJ, Spector TD, Arden NK, Ferreira ML, Radojčić MR. Effects of body weight and fat mass on back pain - direct mechanical or indirect through inflammatory and metabolic parameters? Semin Arthritis Rheum, 2022: in press.
• Radojčić M.R, Perera R.S, Chen L, Spector T.D, Hart D.J, Ferreira M.L, Arden N.K. Specific body mass index trajectories were related to musculoskeletal pain and mortality: 19-year follow-up cohort. Journal of Clinical Epidemiology. 16 September 2021. https://doi.org/10.1016/j.jclinepi.2021.09.020 

• Chen L, Perera RS, Radojčić MR, Beckenkamp P, Ferreira P, Hart DJ, Spector TD, Arden NK, Ferreira ML. Lumbar Spine Radiographic Changes and Back Pain-Related Disability in Middle-Aged, Community-Dwelling Women: A Population-Based Cohort Study. JAMA Network Open 2021;(5):e2110715. 

Work Package	Early Disease and Risk Prediction: Prevent
Objective	1, 1.4
Lead	Maja Radojčić
Investigators	Nigel Arden, Romain Perera (University of Colombo), Manuela Ferreira and Lingxiao Chen (University of Sydney)
Institution	University of Oxford