Background & Aims

Low back pain (LBP) is a prevalent health problem with a significant impact on quality of life[1, 2]. Obesity is a major risk factor for LBP[3] due to increased spinal load, thoracolumbar musculature weakness, altered spinal curvature[4-6] and chronic inflammation[7]. Moreover, obesity favors intervertebral disc extracellular matrix degeneration, adversely affects nerve endings growth[8], and alters the excitation threshold of peripheral nerves, favoring chronic pain sensitization[9]. Bariatric surgery (BS) is the most effective treatment for severe obesity, reducing excess weight and associated comorbidities including LBP[10, 11]. It has been observed that after bariatric surgery, LBP tends to persist[11, 12]. Due to its clinical significance, it is important to unfold factors that are related to LBP and mechanical hyperalgesia in post-BS patients. We compared post- bariatric surgery patients with or without LBP to determine their characteristics and main differences.

This project is supported by the Research Center in Physical Activity, Health, and Leisure—CIAFEL—Faculty of Sport (FADEUP), University of Porto, Portuguese Foundation for Science and Technology (UIDB/00617/2020: doi: 10.54499/UIDB/00617/2020 and UIDP/00617/2020: doi: 10.54499/UIDP/00617/2020), and the Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal (LA/P/0064/2020) and S. João Academic Hospital Center (HSJ), Portugal. Saira Waqqar and Tiago Montanha are funded by Fundação para a Ciência e Tecnologia (FCT) grants 2023.00444.BD, and 2021.05532.BD respectively

Methods

28 post-BS patients (19F:9M; 18-24 months after surgery) were divided into LBP (n=20; 50.5±5years, BMI:32.6±3.8 kg.m-2) and without LBP (n=8; 52.3±7y, BMI:32.1±2.03 kg.m-2). Low back pain intensity (numeric pain rating scale), and Pressure Pain Threshold (PPT; algometer) at the lumbar region, body mass index (BMI), body composition (total and trunk lean and fat mass; DEXA), spine curve angles of the thoracic, lumbar and pelvic regions measured during neutral standing position (Spinal Mouse; IDIAG M360®), and trunk extensors and flexors muscle strength were assessed (Biodex, Isokinetic dynamometer). Independent t-tests and one-way MANOVA were performed to compare groups. Associations between LBP, PPT and dependent variables were explored with Pearson correlation.

Results

Differences between groups were observed for total fat mass, total lean mass, trunk extensors strength, PPT, and lumbar scoliosis: F (5,22) =2.62, p=0.05; Wilk’s ?=0.63, ?p2 =0.37. There were no statistically significant differences in trunk fat mass, trunk lean mass, thoracic kyphosis, thoracic scoliosis, lumbar lordosis angle (LLA), and pelvic tilt (PT) between groups (p>0.05). Patients with and without LBP had spine alignment imbalances including hyper-kyphosis in 61% vs 21%, flat back in 54% vs 25%, mild lumbar scoliosis, and compensatory PT in 32% vs 4%, with no statistically significant difference (p>0.05). LBP was associated with lower total lean mass (r= -0.41, p=0.03), weaker trunk extensor and flexor strength (r=-0.38, p=0.04: r=-0.48, p=0.01), higher fat mass (r=0.40, p=0.04), and lumbar scoliosis (r=0.45, p=0.02). In contrast, PPT was associated with weaker trunk flexors (r=0.37, p=0.05), changes in spine angle i.e., LLA (r= -0.45, p=0.02), and PT (r=-0.52, p=0.00).

Conclusions

Results indicate that post bariatric surgery patients with low back pain have lower total lean mass and trunk extensors strength. Also, pain sensitivity to pressure at the lumbar region and total fat mass were higher, while scoliosis at lumbar region tended to be more prevalent in patients with LBP compared to those without LBP.

References

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2.Mahdavi, S.B., et al., Association between sedentary behavior and low back pain; A systematic review and meta-analysis. Health promotion perspectives, 2021. 11(4): p. 393. DOI: 10.34172/hpp.2021.50
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7.Risbud, M.V. and I.M. Shapiro, Role of cytokines in intervertebral disc degeneration: pain and disc content. Nature Reviews Rheumatology, 2014. 10(1): p. 44-56. DOI: 10.1038/nrrheum.2013.160
8.Delgado-López, P.D. and J.M. Castilla-Díez, Impact of obesity in the pathophysiology of degenerative disk disease and in the morbidity and outcome of lumbar spine surgery. Neurocirugía (English Edition), 2018. 29(2): p. 93-102. doi: 10.1016/j.neucir.2017.06.002.
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Presenting Author

Saira Waqqar

Poster Authors

Saira Waqqar

BSc-PT, PP-DPT & MHPE

Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto (FADEUP) and Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal

Lead Author

Tiago Montanha: Master in Physical Activity and Health

Masters in Physical Activity and Health

Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto (FADEUP) and Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal

Lead Author

Nelson Azevedo: PhD in Physiotherapy

PT, BSc, MSc, PhD Physiotherapy

CICS, ISAVE, Rua Castelo de Almourol, nº 13 4720-155 Amares – Braga, CIR, ESS, Polytechnic of Porto, Rua Dr. António Bernardino de Almeida nº 400 4200-072 - Porto

Lead Author

Dr. Eduardo Costa:Master in Molecular Medicine,Medicine degree

Masters in molecular medicine, Medicine degree

Obesity Integrated Responsibility Unit (CRI-O), São João University Medical Center, Porto, Portugal

Lead Author

Hélder Fonseca: PhD Physical Activity and Health

PhD Physical Activity and Health

Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto (FADEUP) and Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal

Lead Author

José carlos Ribeiro: PhD sport sciences

PhD sport sciences

Research Center in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport, University of Porto (FADEUP) and Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Low Back Pain