**Preface to "Lifestyle and Chronic Pain"**

The Key Role of Lifestyle Factors in Sustaining Chronic Pain: Towards Precision Pain Medicine Chronic pain has a tremendous personal and socioeconomic impact and remains a challenge for many clinicians. Cumulating evidence shows that lifestyle factors such as physical (in)activity, stress, poor sleep, unhealthy diet, and smoking are associated with chronic pain severity and sustainment across all age categories (1). Precision medicine refers to the ability to classify patients into subgroups that differ in their susceptibility to, biology, or prognosis of a particular disease, or in their response to a specific treatment, and thus to tailor treatment to the individual patient characteristics (2). A paradigm shift from a tissue- and disease-based approach towards individually tailored multimodal lifestyle interventions should lead to improved outcomes and decrease the psychological and socioeconomic burden of chronic pain. Such an approach fits well into the global move towards precision pain medicine for patients with chronic pain (3). For all these reasons, this special issue of Journal of Clinical Medicine is dedicated to Lifestyle and Chronic Pain.

The Special Issue includes featured state of the art papers addressing key lifestyle factors of importance to patients having persistent pain and written by leading experts and key opinion leaders in the field. For instance, an exciting state of the art review proposes to clinicians working with patients with chronic pelvic pain to make use of the window of opportunity to prevent a potential transition from localized or periodic pain in the pelvis (e.g., pain during pregnancy and after delivery) towards persistent chronic pain, by promoting a healthy lifestyle (4). In addition, original contributions to this Special Issue include literature reviews (systematic literature reviews with meta analyses and narrative reviews) and exciting original research (trials, cohort studies, experimental lab work, case-control studies) focussed on lifestyle and chronic pain. For instance, an exciting study reports that graded exposure in vivo treatment in patients with chronic low back pain and complex regional pain syndrome type I was accompanied by reductions in fear that preceded pain relief (5). In 164 patients with chronic pain, opioid use was more closely related to perceived injustice and depression, but not anxiety and stress (6). In more than 70% of patients post COVID-19 infection (total n=567), symptoms of central sensitisation were present (7). The authors suggest that patient education and multimodal rehabilitation to target nociplastic pain can be considered in patients post COVID-19 infection with long-lasting symptoms of central sensitisation (7).

In patients with episodic and chronic migraines, less mobility and less velocity of neck movements, without differences in muscle activity, was observed, with neck disability and kinesiophobia being negative and weakly associated with cervical movement (8). This brings us to physical activity as a key lifestyle factor in patients with chronic pain, and the potential of exercise therapy and physical activity interventions to address this factor. A systematic literature review included in this Special Issue discusses the available evidence (including short- and long-term effects) supporting specific versus general exercise therapy for patients with chronic neck and shoulder pain (9).

Sleep is another key lifestyle factor in many patients with chronic pain (10), which was addressed by several papers included in the Special Issue. A state of the art review provided recommendations for best practices in the clinical assessment and treatment approaches to promote sleep health in children and adolescents with chronic pain (11). A systematic literature review with meta-analyses provides an overview of the associates of insomnia in people with chronic spinal pain, highlighting several significant associates of insomnia (12). This review is helpful in gaining a better understanding of the characteristics and potential origin of insomnia in patients with chronic spinal pain, including identifying patients with chronic spinal pain who are likely to have insomnia (12). Finally, an original research report presents the cross-cultural translation and validation of the Pain and Sleep Questionnaire three-item index (PSQ-3) (13), allowing implementation of the PSQ-3 In Finland, potentially leading to better understanding of the direct effects of pain on sleep in Finish patients with chronic pain (13).

Diet is another key lifestyle factor that is gaining scientific momentum in relation to chronic pain (treatment) (14, 15). This Special Issue contributes to this global move with an original research report that studied 2,367 middle-aged and older adults, and found that low protein intake and lack of regular exercise are associated with high odds for low back pain in women (16). In addition, a review describes the current state of the art regarding nutrition in patients with chronic (non-cancer) pain, highlighting why nutrition is critical within a person-centred approach to pain management, and providing recommendations to guide clinicians in doing so (17). In addition, another review included in this Special Issue focusses on patients with post-cancer pain, and argues that diet/nutrition might be ready to transition from a cancer recurrence/prevention strategy towards a chronic pain management modality for cancer survivors (18). The importance of evidence-based pain management in cancer survivors is another global trend thoroughly addressed in this Special Issue, with another state of the art review discussing how multiple modifiable lifestyle factors, such as stress, insomnia, diet, obesity, smoking, alcohol consumption and physical activity, play a role in shaping the pain experience after cancer, and how available treatment programs for cancer survivors can be improved by including an individually-tailored lifestyle management approach (19).

Together, this Special Issue contributes substantially to the paradigm shift towards a lifestyle approach for patients having non-cancer and cancer-related chronic pain!

#### **References**

1. Nijs J, D'Hondt E, Clarys P, Deliens T, Polli A, Malfliet A, Coppieters I, Willaert W, Tumkaya Yilmaz S, Elma O, Ickmans K. Lifestyle and Chronic Pain across the Lifespan: An Inconvenient Truth? ¨ Pm r. 2020;12(4):410-419.

2. National Research Council Committee on AFfDaNToD. The National Academies Collection: Reports funded by National Institutes of Health. Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease. Washington (DC): National Academies Press (US) Copyright ©2011, National Academy of Sciences.; 2011.

3. Nijs JG, SZ; Clauw, DJ; Fernandez-de-las-Pe ´ nas, C; Kosek, E; Ickmans, K; Fern ˜ andez Carnero, ´ J; Polli, A; Kapreli, E; Huysmans, E; Cuesta-Vargas, AI; Mani, R; Lundberg, M; Leysen, L; Rice, D; Sterling, M; Curatolo, M. . Central sensitisation in chronic pain conditions: Latest discoveries and their potential for precision medicine. The Lancet Rheumatology 2021;3:e383-392.

4. Gutke A, Sundfeldt K, De Baets L. Lifestyle and Chronic Pain in the Pelvis: State of the Art and Future Directions. Journal of Clinical Medicine. 2021;10(22):5397.

5. Bontinck J, den Hollander M, Kaas AL, De Jong JR, Timmers I. Individual Patterns and Temporal Trajectories of Changes in Fear and Pain during Exposure In Vivo: A Multiple Single-Case Experimental Design in Patients with Chronic Pain. J Clin Med. 2022;11(5).

6. Kleinmann B, Wolter T. Opioid Consumption in Chronic Pain Patients: Role of Perceived Injustice and Other Psychological and Socioeconomic Factors. Journal of Clinical Medicine. 2022;11(3):647.

7. Goudman L, De Smedt A, Noppen M, Moens M. Is Central Sensitisation the Missing Link of Persisting Symptoms after COVID-19 Infection? Journal of Clinical Medicine. 2021;10(23):5594.

8. Pinheiro CF, Oliveira AS, Will-Lemos T, Florencio LL, Fernandez-de-las-Pe ´ nas C, Dach F, ˜

Bevilaqua-Grossi D. Neck Active Movements Assessment in Women with Episodic and Chronic Migraine. Journal of Clinical Medicine. 2021;10(17):3805.

9. Duenas L, Aguilar-Rodr ˜ ´ıguez M, Voogt L, Lluch E, Struyf F, Mertens MGCAM, Meulemeester KD, Meeus M. Specific versus Non-Specific Exercises for Chronic Neck or Shoulder Pain: A Systematic Review. Journal of Clinical Medicine. 2021;10(24):5946.

10. Nijs J, Mairesse O, Neu D, Leysen L, Danneels L, Cagnie B, Meeus M, Moens M, Ickmans K, Goubert D. Sleep Disturbances in Chronic Pain: Neurobiology, Assessment, and Treatment in Physical Therapist Practice. Phys Ther. 2018;98(5):325-335.

11. Law EF, Kim A, Ickmans K, Palermo TM. Sleep Health Assessment and Treatment in Children and Adolescents with Chronic Pain: State of the Art and Future Directions. Journal of Clinical Medicine. 2022;11(6):1491.

12. Bilterys T, Siffain C, De Maeyer I, Van Looveren E, Mairesse O, Nijs J, Meeus M, Ickmans K, Cagnie B, Goubert D, Danneels L, Moens M, Malfliet A. Associates of Insomnia in People with Chronic Spinal Pain: A Systematic Review and Meta-Analysis. J Clin Med. 2021;10(14).

13. Mikkonen J, Leinonen V, Luomajoki H, Kaski D, Kupari S, Tarvainen M, Selander T, Airaksinen O. Cross-Cultural Adaptation, Reliability, and Psychophysical Validation of the Pain and Sleep Questionnaire Three-Item Index in Finnish. Journal of Clinical Medicine. 2021;10(21):4887.

14. Elma O, Yilmaz ST, Deliens T, Coppieters I, Clarys P, Nijs J, Malfliet A. Do Nutritional Factors ¨ Interact with Chronic Musculoskeletal Pain? A Systematic Review. J Clin Med. 2020;9(3).

15. Nijs J, Tumkaya Yilmaz S, Elma O, Tatta J, Mullie P, Vanderwee ¨ en L, Clarys P, Deliens T, ¨ Coppieters I, Weltens N, Van Oudenhove L, Huysmans E, Malfliet A. Nutritional intervention in chronic pain: an innovative way of targeting central nervous system sensitization? Expert Opin Ther Targets. 2020;24(8):793-803.

16. Noh HM, Choi YH, Lee SK, Song HJ, Park YS, Kim N, Cho J. Association between Dietary Protein Intake, Regular Exercise, and Low Back Pain among Middle-Aged and Older Korean Adults without Osteoarthritis of the Lumbar Spine. J Clin Med. 2022;11(5).

17. Brain K, Burrows TL, Bruggink L, Malfliet A, Hayes C, Hodson FJ, Collins CE. Diet and Chronic Non-Cancer Pain: The State of the Art and Future Directions. Journal of Clinical Medicine. 2021;10(21):5203.

18. Tumkaya Yılmaz S, Malfliet A, Elma ¨ O, Deliens T, Nijs J, Clarys P, De Groef A, Coppieters ¨ I. Diet/Nutrition: Ready to Transition from a Cancer Recurrence/Prevention Strategy to a Chronic Pain Management Modality for Cancer Survivors? J Clin Med. 2022;11(3).

19. Lahousse A, Roose E, Leysen L, Yilmaz ST, Mostaqim K, Reis F, Rheel E, Beckwee D, Nijs ´ J. Lifestyle and Pain following Cancer: State-of-the-Art and Future Directions. Journal of Clinical Medicine. 2022;11(1):195.

> **Jo Nijs and Felipe J J Reis** *Editors*
