Impaired Carbohydrate Metabolism among Women with Chronic Low Back Pain and the Role of Dietary Carbohydrates: A Randomized Controlled Cross-Over Experiment.

Background: Impaired glucose regulation is suggested to be related to chronic low back pain (CLBP), although it is not clear how they interact with each other. Thus, the primary aim of this study was to investigate differences in postprandial glycemic responses (PPGRs) (the first sign of impaired glucose metabolism) to high- (sucrose) and low-glycemic index (GI) (isomaltulose) beverages in normoglycemic women with CLBP and healthy controls (HCs) and explore whether any group that showed greater PPGRs to high-GI beverage intake would benefit when the high-GI beverage was replaced with a low-GI beverage. Secondly, this study aimed to explore the association between PPGR and pain in patients with CLBP. Methods: This study was registered at clinicaltrials.org (NCT04459104) before the start of the study. In this study, 53 CLBP patients and 53 HCs were recruited. After 11-12 h of fasting, each participant randomly received isomaltulose or sucrose. Blood glucose levels were measured during the fasting state and 15, 30, 45, 60, 90, and 120 min after the beverage intake, and each participant underwent experimental pain measures. Results: Compared to the HCs, the CLBP group showed significantly higher PPGRs to sucrose (p < 0.021). Additionally, the CLBP group showed a significantly higher decrease in PPGR (p = 0.045) when comparing PPGR to sucrose with PPGR to isomaltulose. Correlation analysis revealed a positive association between self-reported pain sensitivity and PPGR to sucrose, while there was no association found between any experimental pain measures and glycemic responses. Conclusions: Overall, these findings suggest that normoglycemic CLBP patients might have a higher risk of developing impaired glucose tolerance than the HCs and might benefit more when high-GI foods are replaced with low-GI ones.

Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations.

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Proinflammatory Dietary Intake Relates to Pain Sensitivity in Chronic Nonspecific Low Back Pain: A Case-Control Study.

Nonspecific chronic low back pain (nCLBP) has been associated with nutrition. Yet, it is not clear how nutritional factors and nCLBP relate to one another. Therefore, the aim of the present study was to investigate differences in diet quality and dietary intake levels between nCLBP patients and healthy controls (HCs) and explore the association between nutritional factors and pain sensitivity in nCLBP. In this case-control study, 106 participants (ie, n = 53 nCLBP and n = 53 HCs) were recruited and completed a 3-day food diary to assess their dietary intake, which allowed to generate individual diet quality scores (ie, the Healthy Eating Index-2015 and Dietary Inflammatory Index). Additionally, each participant underwent an experimental pain assessment (quantitative sensory testing) and filled out self-reported pain questionnaires. Compared to HCs, the nCLBP group showed significantly lower diet quality, higher inflammatory scores, and a lower intake of total protein, total fat, dietary fiber, omega-3 fatty acids, vitamin B6, vitamin A, beta-carotene, vitamin E, and magnesium. Pain sensitivity mainly showed a negative correlation with nutritional intakes known for anti-inflammatory properties (ie, vitamins E, D, A, B6, B12, and zinc). Interestingly, total fat, cholesterol, saturated, and monounsaturated fat intakes were found to be inversely associated with pain sensitivity. Overall, patients with nCLBP have a lower diet quality, eat more proinflammatory, have less intake of nutrients known for their anti-inflammatory and antioxidative properties, and drink less water compared to HCs. Accordingly, pain sensitivity was mainly found to be positively associated with proinflammatory dietary intake. PERSPECTIVE: This study emphasizes the association between a proinflammatory diet and nCLBP. Among nCLBP patients, positive association between increased pain sensitivity and the proinflammatory potential of a diet, highlighting the potential for individualized pain management strategies and leading to the development of novel therapeutic methods.

Towards precision pain medicine for pain after cancer: the Cancer Pain Phenotyping Network multidisciplinary international guidelines for pain phenotyping using nociplastic pain criteria.

Pain after cancer remains underestimated and undertreated. Precision medicine is a recent concept that 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. Applying this to pain after cancer, the ability to classify post-cancer pain into the three major pain phenotypes (i.e. nociceptive, neuropathic, and nociplastic pain) and tailor pain treatment accordingly, is an emerging issue. This is especially relevant because available evidence suggests that nociplastic pain is present in an important subgroup of those patients experiencing post-cancer pain. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system for nociplastic pain account for the need to identify and correctly classify patients according to the pain phenotype early in their treatment. These criteria are an important step towards precision pain medicine with great potential for the field of clinical oncology. Within this framework, the Cancer Pain Phenotyping (CANPPHE) Network, an international and interdisciplinary group of oncology clinicians and researchers from seven countries, applied the 2021 IASP clinical criteria for nociplastic pain to the growing population of those experiencing post-cancer pain. A manual is provided to allow clinicians to differentiate between predominant nociceptive, neuropathic, or nociplastic pain after cancer. A seven-step diagnostic approach is presented and illustrated using cases to enhance understanding and encourage effective implementation of this approach in clinical practice.

The Importance of Nutrition as a Lifestyle Factor in Chronic Pain Management: A Narrative Review.

In everyday clinical practice, healthcare professionals often meet chronic pain patients with a poor nutritional status. A poor nutritional status such as malnutrition, unhealthy dietary behaviors, and a suboptimal dietary intake can play a significant role in the occurrence, development, and prognosis of chronic pain. The relationship between nutrition and chronic pain is complex and may involve many underlying mechanisms such as oxidative stress, inflammation, and glucose metabolism. As such, pain management requires a comprehensive and interdisciplinary approach that includes nutrition. Nutrition is the top modifiable lifestyle factor for chronic non-communicable diseases including chronic pain. Optimizing one's dietary intake and behavior needs to be considered in pain management. Thus, this narrative review reports and summarizes the existing evidence regarding (1) the nutrition-related health of people experiencing pain (2) the underlying potential mechanisms that explain the interaction between nutrition and chronic pain, and (3) the role of nutrition screening, assessment and evaluation for people experiencing pain and the scope of nutrition practice in pain management. Future directions in the nutrition and chronic pain field are also discussed.

Diet/Nutrition: Ready to Transition from a Cancer Recurrence/Prevention Strategy to a Chronic Pain Management Modality for Cancer Survivors?

Evidence for the relationship between chronic pain and nutrition is mounting, and chronic pain following cancer is gaining recognition as a significant area for improving health care in the cancer survivorship population. This review explains why nutrition should be considered to be an important component in chronic pain management in cancer survivors by exploring relevant evidence from the literature and how to translate this knowledge into clinical practice. This review was built on relevant evidence from both human and pre-clinical studies identified in PubMed, Web of Science and Embase databases. Given the relationship between chronic pain, inflammation, and metabolism found in the literature, it is advised to look for a strategic dietary intervention in cancer survivors. Dietary interventions may result in weight loss, a healthy body weight, good diet quality, systemic inflammation, and immune system regulations, and a healthy gut microbiota environment, all of which may alter the pain-related pathways and mechanisms. In addition to being a cancer recurrence or prevention strategy, nutrition may become a chronic pain management modality for cancer survivors. Although additional research is needed before implementing nutrition as an evidence-based management modality for chronic pain in cancer survivors, it is already critical to counsel and inform this patient population about the importance of a healthy diet based on the data available so far.

The Critical Role of Nutrition Care to Improve Pain Management: A Global Call to Action for Physical Therapist Practice.

Physical therapists have unique education in the comprehensive biopsychosocial assessment and treatment of chronic pain and its mechanisms. Recently, physical therapists have raised awareness regarding the impact of nutrition on promoting health and managing noncommunicable diseases. Robust evidence supports the implementation of nutrition in physical therapist education and practice. Of particular interest for the physical therapist are investigations that use dietary interventions for the treatment of chronic pain. Yet physical therapists have received little guidance regarding their role in nutrition care for pain management and may pass on opportunities to counsel their patients on the connection between nutrition and pain. Therefore, a clinical paradigm shift and unified voice within the profession is called on to encourage physical therapists to develop tailored multimodal lifestyle interventions that include nutrition care for the management of chronic pain. This Perspective describes evidence supporting the implementation of nutrition care in physical therapist practice, supports the role of nutritional pain management for physical therapists, and encourages the use of nutrition care for primary, secondary, tertiary, prevention, health promotion, and wellness related to chronic pain. To achieve these aims, this Perspective offers suggestions for how physical therapists can (1) enhance clinical decision making; (2) expand professional, jurisdictional, and personal scope of practice; (3) evolve entry-level education; and (4) stimulate new investigations in nutrition care and pain science research. In doing so, physical therapists can assert their role throughout the pain management continuum, champion innovative research initiatives, and enhance public health by reducing the impact of chronic pain. IMPACT: The nutrition care process for pain management is defined as the basic duty to provide adequate and appropriate nutrition education and counseling to people living with pain. Including the nutrition care process as part of a multimodal approach to pain management provides an opportunity for physical therapists to assert their role throughout the pain management continuum. This includes championing innovative research initiatives and enhancing public health by reducing the impact of chronic pain for over 50 million Americans.

Diet can exert both analgesic and pronociceptive effects in acute and chronic pain models: a systematic review of preclinical studies.

BACKGROUND: Although diet is an essential aspect of human health, the link between diet and pain is still not well understood. Preclinical animal research provides information to understand underlying mechanisms that allow identifying the needs for human research. OBJECTIVES: This study aims to give a systematic overview of the current evidence from preclinical studies regarding the analgesic and pronociceptive effects of various diets in non-neuropathic, non-cancer, or non-visceral acute and chronic pain models. STUDY DESIGN: A systematic Review. SETTING: This study examined studies that investigate the analgesic and pronociceptive effects of various diets in non-neuropathic, non-cancer, or non-visceral acute and chronic pain models. METHODS: This review was conducted following the PRISMA guidelines and was registered in PROSPERO with the registration number CRD42019133473. The certainty of evidence was examined by a modified GRADE approach. RESULTS: After the screening process twenty-four eligible papers were included in this review. Nineteen studies examined acute pain, nine studies chronic inflammatory pain, and four studies assessed both acute and chronic pain models. LIMITATIONS: Due to the heterogeneity of the included studies, a meta-analysis was not included in this study. CONCLUSIONS: In animal models, excessive saturated, monounsaturated or omega-6 polyunsaturated fat ingestion and diets rich in fats and carbohydrates can decrease pain sensitivity in acute nociceptive pain, whereas it can induce mechanical allodynia and heat hyperalgesia in chronic inflammatory pain. Additionally, diets rich in anti-inflammatory ingredients, as well as a calorie-restricted diet can promote recovery from primary mechanical allodynia and heat hyperalgesia in chronic inflammatory pain.

Obesity Hurts: The Why and How of Integrating Weight Reduction With Chronic Pain Management.

Amongst adults with chronic pain, overweight and obesity are highly prevalent. The association between chronic pain and overweight is driven by several explanations, including increased biomechanical load, changes in the gut microbiome, and low-grade (neuro)inflammation. Moreover, the link between overweight, obesity and chronic pain can best be considered from a lifestyle perspective. Since conservative treatment for chronic pain is often limited to short-term and small effects, addressing important comorbidities within a lifestyle approach could be the next step towards precision medicine for these patients. Indeed, evidence shows that combining weight reduction with conservative pain management is more effective to reduce pain and disability, compared to either intervention alone. This perspective article aims to update the reader with the current understanding of the possible explanatory mechanisms behind the interaction between overweight/obesity and chronic pain in an adult population. Second, this paper applies this knowledge to clinical practice, including assessment and conservative treatment of overweight/obesity in adults with chronic pain. Henceforth, clinical recommendations and guidelines are provided based on available scientific evidence and the authors' clinical expertise. IMPACT: This paper will guide clinicians in the implementation of weight reduction programs within pain management.

Nutrition/Dietary Supplements and Chronic Pain in Patients with Cancer and Survivors of Cancer: A Systematic Review and Research Agenda.

BACKGROUND: Chronic pain is one of the most often seen, but often undertreated, sequelae in survivors of cancer. Also, this population often shows significant nutritional deficiencies, which can affect quality of life, general health status, and even risk of relapse. Given the influence of nutrition on brain plasticity and function, which in turn is associated with chronic pain in the population with cancer, it becomes relevant to focus on the association between pain and nutritional aspects in this population. OBJECTIVE: To identify relevant evidence regarding nutrition and chronic pain in patients with cancer/survivors of cancer. STUDY DESIGN: Systematic review. METHODS: PubMed, Embase, and Web of Science were systematically searched for interventional and experimental studies that included patients with cancer /survivors of cancer with chronic pain, a nutrition-related observation/examination, and a pain-related outcome. Studies that complied with the inclusion and exclusion criteria were screened for methodological quality and risk of bias by using the Qualsyst (standard quality assessment criteria for evaluating primary research) tool. RESULTS: The 2 included studies entailed uncontrolled trials which examined different nutritional supplements usage in various patients with cancer (breast, gastrointestinal and gynecological  cancers). One study evaluated the effects of vitamin C, but did not report a change in pain outcomes. The other study, looking at the nutritional supplements glucosamine and chondroitin, found an improvement in pain after 12- and 24 weeks. LIMITATIONS: The limitations to the generalization of these results include the insufficient amount of eligible studies and diversity in therapeutic interventions and participant groups. CONCLUSION: The association between nutrition and chronic pain in patients with cancer /survivors of cancer is not well documented. The available studies are uncontrolled, and are therefore limited to draw firm conclusions. Additional research is highly needed, and a research agenda is proposed within this paper.

Transcutaneous electrical nerve stimulation and heat to reduce pain in a chronic low back pain population: a randomized controlled clinical trial.

BACKGROUND: Low back pain is the leading cause of disability worldwide. The therapeutic management of patients with chronic LBP is challenging. OBJECTIVES: The aim of this study is to evaluate the effects of heat and transcutaneous electrical nerve stimulation combined on pain relief in participants with chronic low back pain. METHODS: Fifty participants with chronic (≥3 months) low back pain were randomly assigned to two groups: HeatTens (n=25) and control group (n=25). Primary outcome was pain. Secondary outcomes were pressure pain thresholds, temporal summation, conditioned pain modulation, fear-avoidance and beliefs questionnaire, central sensitization inventory, quality of life, and medication use. The control group received no treatment and continued usual care. After four weeks of treatment, all measurements were repeated. RESULTS: Fifty individuals participated in this study. Significant higher pressure pain threshold measures after both 30min and 4 weeks for the lower back region and the second plantar toe were found only in the experimental group. CONCLUSION: The combination of heat and transcutaneous electrical nerve stimulation does not reduce pain scores in patients with chronic low back pain. Pressure pain threshold values significantly improved, showing beneficial effects of the experimental treatment. ClinicalTrials.gov: NCT03643731 (https://clinicaltrials.gov/ct2/show/NCT03643731).

Nutritional intervention in chronic pain: an innovative way of targeting central nervous system sensitization?

INTRODUCTION: Few treatment programs for chronic pain nowadays take a dietary pattern or adipose status into account. AREAS COVERED: An important role of neuroinflammation in chronic pain is now well established, at least in part due to increased central nervous system glial activation. Based on preclinical studies, it is postulated that the interaction between nutrition and central sensitization is mediated via bidirectional gut-brain interactions. This model of diet-induced neuroinflammation and consequent central sensitization generates a rationale for developing innovative treatments for patients with chronic pain. Methods: An umbrella approach to cover the authors' expert opinion within an evidence-based viewpoint. EXPERT OPINION: A low-saturated fat and low-added sugar dietary pattern potentially decreases oxidative stress, preventing Toll-like receptor activation and subsequent glial activation. A low-saturated fat and low-added sugar diet might also prevent afferent vagal nerve fibers sensing the pro-inflammatory mediators that come along with a high-(saturated) fat or energy-dense dietary pattern, thereby preventing them to signal peripheral inflammatory status to the brain. In addition, the gut microbiota produces polyamines, which hold the capacity to excite N-methyl-D-aspartate receptors, an essential component of the central nervous system sensitization. Hence, a diet reducing polyamine production by the gut microbiota requires exploration as a therapeutic target for cancer-related and non-cancer chronic pain.

Do Nutritional Factors Interact with Chronic Musculoskeletal Pain? A Systematic Review.

Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients' diet, and chronic musculoskeletal pain remains unclear. Therefore, the purpose of this review was to systematically review the literature on the link between dietary patterns, the components of patients' diet and chronic musculoskeletal pain. This review was conducted following the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) guidelines and was registered in PROSPERO with the registration number CRD42018110782. PubMed, Web of Science, and Embase online databases were searched. After screening titles and abstracts of 20,316 articles and full texts of 347 articles, 12 eligible articles were included in this review, consisting of nine experimental and three observational studies. Seven out of nine experimental studies reported a pain-relieving effect of dietary changes. Additionally, protein, fat, and sugar intake were found to be associated with pain intensity and pain threshold. In conclusion, plant-based diets might have pain relieving effects on chronic musculoskeletal pain. Patients with chronic rheumatoid arthritis pain can show inadequate intake of calcium, folate, zinc, magnesium, and vitamin B6, whilst patients with fibromyalgia can show a lower intake of carbohydrates, proteins, lipids, vitamin A-E-K, folate, selenium, and zinc. Chronic pain severity also shows a positive relation with fat and sugar intake in osteoarthritis, and pain threshold shows a positive association with protein intake in fibromyalgia.

Chronic Musculoskeletal Pain and Nutrition: Where Are We and Where Are We Heading?

Nutrition is one of the most important lifestyle factors related to chronic diseases such as cancer, diabetes, and cardiovascular diseases. Additionally, poor diet is also considered a predicting, perpetuating, or underlying factor in chronic musculoskeletal pain. This narrative review provides an overview of current knowledge on the relationship between nutrition and chronic musculoskeletal pain (ie, inflammation, obesity, homeostatic balance, and central sensitization as underlying mechanisms). This review also identifies how dietary intake assessments and nutritional behavior interventions for chronic musculoskeletal pain can be used in clinical practice and identifies areas in need of additional research. Based on the available literature, dietary behavior and quality could have an impact on chronic musculoskeletal pain conditions, but the direction of this impact is unclear. There is a need for additional human nutrition studies that focus on specific musculoskeletal pain conditions and underlying pathologies.

Lifestyle and Chronic Pain across the Lifespan: An Inconvenient Truth?

Chronic pain has a tremendous personal and socioeconomic impact and remains difficult to treat. Therefore, it is important to provide an update on the current understanding regarding lifestyle factors in people with chronic pain across the lifespan. Lifestyle factors such as physical (in)activity, sedentary behavior, stress, poor sleep, unhealthy diet, and smoking are associated with chronic pain severity and sustainment. This applies to all age categories, that is, chronic pain across the lifespan. Yet current treatment options often do not or only partly address the many lifestyle factors associated with chronic pain or attempt to address them in a standard format rather than providing an individually tailored multimodal lifestyle intervention. The evidence regarding lifestyle factors is available in adults, but limited in children and older adults having chronic pain, providing important avenues for future research. In conclusion, it is proposed that treatment approaches for people with chronic pain should address all relevant lifestyle factors concomitantly in an individually-tailored multimodal intervention. Ultimately, this should lead to improved outcomes and decrease the psychological and socioeconomic burden of chronic pain. Level of Evidence: IV.