Relations of C-Reactive Protein and Obesity to the Prevalence and the Odds of Reporting Low Back Pain

Elevated C-Reactive Protein in Older Men With Chronic Pain: Association With Plasma Amyloid Levels and Hippocampal Volume

BACKGROUND

Chronic pain leads to tau accumulation and hippocampal atrophy, which may be moderated through inflammation. In older men, we examined associations of chronic pain with Alzheimer's disease (AD)-related plasma biomarkers and hippocampal volume as moderated by systemic inflammation.

METHODS

Participants were men without dementia. Chronic pain was defined as moderate-to-severe pain in 2+ study waves at average ages 56, 62, and 68. At age 68, we measured plasma amyloid-beta (Aβ42, n = 871), Aβ40 (n = 887), total tau (t-tau, n = 841), and neurofilament light chain (NfL, n = 915), and serum high-sensitivity C-reactive protein (hs-CRP, n = 968), a marker of systemic inflammation. A subgroup underwent structural MRI to measure hippocampal volume (n = 385). Analyses adjusted for medical morbidities, depressive symptoms, and opioid use.

RESULTS

Chronic pain was related to higher Aβ40 (β = 0.25, p = .009), but hs-CRP was unrelated to AD-related biomarkers (ps > .05). There was a significant interaction such that older men with both chronic pain and higher levels of hs-CRP had higher levels of Aβ42 (β = 0.36, p = .001) and Aβ40 (β = 0.29, p = .003). Chronic pain and hs-CRP did not interact to predict levels of Aβ42/Aβ40, t-tau, or NfL. Furthermore, there were significant interactions such that Aβ42 and Aβ40 were associated with lower hippocampal volume, particularly when levels of hs-CRP were elevated (hs-CRP × Aβ42: β = -0.19, p = .002; hs-CRP × Aβ40: β = -0.21, p = .001), regardless of chronic pain status.

CONCLUSIONS

Chronic pain was associated with higher plasma Aβ, especially when hs-CRP was also elevated. Higher hs-CRP and Aβ levels were both related to smaller hippocampal volumes. Chronic pain, when accompanied by systemic inflammation, may elevate the risk of neurodegeneration in AD-vulnerable regions.

Association between lipid-lowering agents with intervertebral disc degeneration, sciatica and low back pain: a drug-targeted mendelian randomized study and cross-sectional observation

BACKGROUND

Abnormal lipid metabolism is linked to intervertebral disc degeneration (IVDD), sciatica, and low back pain (LBP), but it remains unclear whether targeted interventions can prevent these issues. This study investigated the causal effects of lipid-lowering drug use on IVDD, sciatica, and LBP development.

METHODS

Single-nucleotide polymorphisms (SNPs) linked to total cholesterol (TC), low-density-lipoprotein cholesterol (LDL-C), and non-high-density-lipoprotein cholesterol (non-HDL-C) were obtained from the Global Lipids Genetics Consortium's genome-wide association study (GWAS). Genes near HMGCR, PCSK9, and NPC1L1 were selected to represent therapeutic inhibition targets. Using Mendelian randomization (MR) focusing on these drug targets, we identified causal effects of PCSK9, HMGCR, and NPC1L1 on the risk of developing IVDD, sciatica, and LBP, with coronary heart disease risk serving as a positive control. Using summary data from Mendelian randomization (SMR) analysis, we evaluated potential therapeutic targets for IVDD, sciatica, and LBP through protein quantitative trait loci (pQTL). The genetic associations with IVDD, sciatica, LBP, and coronary heart disease were derived from FinnGen (discovery) and UK Biobank (replication). Additionally, a cross-sectional observational study was performed using data from the National Health and Nutrition Examination Survey (NHANES) to further investigate the connection between LBP and statin use, with a sample size of 4343 participants. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to assess the outcomes.

RESULTS

The NHANES-based cross-sectional study indicated that non-statin use was associated with an increased risk of developing LBP (OR = 1.29, 95% CI [1.04, 1.59], P = 0.019). Moreover, Inverse-variance weighting (IVW) analysis revealed that NPC1L1-mediated reductions in TC, LDL-C, and non-HDL-C concentrations were associated with a decreased risk of developing IVDD (P = 9.956E-03; P = 3.516E-02; P = 1.253E-04). Similarly, PCSK9-mediated reductions in LDL-C and TC concentrations were linked to a lower risk of developing sciatica (P = 3.825E-02; P = 2.709E-02). Sensitivity analysis confirmed the stability and reliability of the MR results. MST1 (macrophage stimulating 1) levels was inversely associated with IVDD, sciatica, and LBP risks.

CONCLUSION

The results of cross-sectional study suggested that non-use of statins was positively correlated with LBP. The results of Mendelian randomization study suggest that NPC1L1 could lower the risk of developing IVDD by reducing TC, LDL-C, and non-HDL-C levels. Additionally, PCSK9 may reduce the risk of developing sciatica by lowering LDL-C and TC levels. In contrast, HMGCR appears to have no significant effect on IVDD, sciatica, or LBP development. Nonetheless, further research is needed to verify these preliminary results. MST1 warrants further exploration as a potential therapeutic target. It is necessary to do further research to validate these findings.

Estimating the impact of metabolic syndrome on low back pain and the joint effects of metabolic syndrome and depressive symptoms on low back pain: insights from the China Health and Retirement Longitudinal Study

BACKGROUND

Although metabolic syndrome (MetS) and depressive symptoms (DS) are predictors of low back pain (LBP), their combined effects and relative contributions to LBP have not been well studied. Using the nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS), this study conducted cross-sectional and longitudinal analyses to investigate the impact of MetS on LBP, and the joint effects of MetS and DS on LBP.

METHODS

This study included a cross-sectional analysis of 8957 participants aged at least 45 years from the CHARLS 2011 dataset and a longitudinal follow-up of 3468 participants without LBP from the CHARLS 2011, tracked over 9.25 years (from June 2011 to September 2020) with 4 times LBP assessment in CHARLS 2013, 2015, 2018, and 2020. To explore the association between MetS on LBP and the joint effects of MetS and DS on LBP, multivariable-adjusted multinomial logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Multivariable-adjusted COX proportional hazards regression models were applied to estimate hazard ratios (HRs) and 95% CIs. All statistical analyses were conducted using STATA (version SE16).

RESULTS

In the cross-sectional analysis, MetS was associated with a lower risk of LBP (adjusted OR = 0.85, 95% CI = 0.74-0.97), while there was no significance for this association in the longitudinal analysis. In the joint association of MetS and DS with LBP, participants with NoMetS + DS (adjusted OR = 2.31, 95% CI = 1.94-2.75), and MetS + DS (adjusted OR = 2.16, 95% CI = 1.81-2.59) were risk factors for LBP events, while those with MetS + NoDS (adjusted OR = 0.75, 95% CI = 0.62-0.90) was a protective factor for LBP events than those with NoMetS + NoDS. During the 9.25 years of follow-up, 1708 cases (49.25%) experienced incident LBP events. In the longitudinal analysis, a significantly negative association was not found in MetS + NoDS for LBP events. Three sensitivity analyses identified the robustness of the associations. Moreover, the nature of cross-sectional associations differed by age (45-64 and 65 + years).

CONCLUSIONS

Our study found that MetS was linked to a lower incidence of LBP, but this effect does not persist over time. Importantly, the combination of MetS and DS significantly increased LBP risk, a joint effect not extensively studied before. These findings underscore the novel contribution of our research, advocating for the joint assessment of MetS and DS to enhance LBP risk stratification and inform prevention strategies.

Modulatory effect of sedentary behaviour on obesity and chronic low back pain: a cross-sectional study using data from the National Health and Nutrition Examination Survey

OBJECTIVE

To explore whether sedentary behaviour could modulate the association between overweight or obesity and chronic low back pain (CLBP).

DESIGN

A retrospective cross-sectional study.

SETTING AND PARTICIPANTS

A total of 4289 participants in the US cohort from the National Health and Nutrition Examination Survey were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

CLBP was the outcome.

RESULTS

After adjusting for confounding factors, an increased risk of CLBP was identified in people who were overweight (OR 1.41, 95% CI 1.13 to 1.76) and obesity (OR 1.48, 95% CI 1.01 to 2.18). No significant association between sedentary behaviour time and CLBP was observed. In body mass index (BMI)<25 kg/m2 vs BMI≥30 kg/m2 group, sedentary behaviour time showed a modulatory effect on obesity and CLBP (p=0.047). In the sedentary behaviour time >4.5 hours group, the risk of CLBP was increased as BMI elevation, indicating sedentary behaviour time >4.5 hours played a modulatory role in the relationship between obesity and CLBP.

CONCLUSION

Obesity was significantly associated with an increased risk of CLBP, and sedentary behaviour time modulated the association between obesity and CLBP. The findings might provide a reference for the lifestyle modifications among individuals with obesity and reducing sedentary behaviour is recommended for this population.

Race-specific associations: inflammatory mediators and chronic low back pain

ABSTRACT

Chronic low back pain (cLBP) is a global health crisis that disproportionately burdens non-Hispanic Black (NHB) individuals, compared with those who identify as non-Hispanic White (NHW). Despite the growing personal and societal impact of cLBP, its biological underpinnings remain poorly understood. To elucidate the biological factors that underlie the racial disparities in cLBP, this study sought to determine whether inflammatory mediators associated with pain interference (PI), pain at rest (PAR), and movement-evoked pain (MEP) differ as a function of racial identity. Blood samples were collected from 156 individuals with cLBP (n = 98 NHB participants, n = 58 NHW participants). Enzyme-linked immunosorbent assay and multiplex assays were used to quantify concentrations of proinflammatory (fibrinogen, C-reactive protein [CRP], serum amyloid A, tumor necrosis factor α [TNF-α], and interleukin [IL]-1α, IL-1β, and IL-6) and anti-inflammatory markers (IL-4 and IL-13). Spearman rho correlations were used to assess associations among markers of inflammation and PI, PAR, and MEP using the Brief Pain Inventory-Short Form. Analyses revealed that for NHW patients, CRP, serum amyloid A, and IL-6 were positively associated with cLBP outcomes and IL-4 was inversely associated with PAR and MEP. However, for NHB patients, only IL-1α was positively associated with PAR. Our findings suggest that, while there are associations between inflammation and cLBP outcomes, the biomarkers that underlie the inflammation could very well differ as a function of racialized minority group. However, more research with racially inclusive samples is needed to elucidate the mechanisms that may contribute to racial disparities in cLBP.

Cross-cultural adaptation and validation of the Spanish version of the Oswestry disability index for Mexican population

PURPOSE

This study aimed to adapt a Spanish translation of the Oswestry Disability Index (ODI) into a cross-cultural version for the Mexican population. The objectives were to verify the validity and reliability of the adapted ODI and to compare pain perception between patients with and without obesity.

MATERIAL AND METHODS

We included 102 patients with low back pain from two neurosurgery departments in Mexico. The ODI questionnaire was translated and culturally adapted. Validity and construct were evaluated using exploratory factor analysis, and the external convergent validity was assessed by correlating ODI scores with pain intensity, age, and obesity. Test-retest reliability was calculated using the intraclass correlation coefficient, and confirmatory analysis was employed to validate the factorial structure.

RESULTS

Patients with obesity were older and had higher pain scores than patients without obesity. The exploratory analysis of the ODI in Mexican Spanish showed good reliability (Cronbach's alpha of 0.923) and validity (factorial loading range, 0.681 - 0.818). The confirmatory analysis showed almost null or very low discrepancy between the proposed model and the real data.

CONCLUSIONS

A Spanish translation of ODI was cross-culturally adapted for the Mexican population. The Mexican version of the ODI showed good reliability and validity in Mexican culture.

Predictive Validity of Multifactorial Injury Risk Models and Associated Clinical Measures in the U.S. Population

Background: Popular movement-based injury risk screens were shown to lack predictive precision, leading to interest in multifactorial models. Furthermore, there is a lack of research regarding injury risk assessment for those currently or planning to be recreationally active. This study aims to provide injury risk insights by analyzing multifactorial injury risk models and associated clinical measures in the U.S. population. Methods: Data related to injury, inflammatory markers, physical functioning, body composition, physical activity, and other variables from 21,033 respondents were extracted from NHANES. Odds ratios for self-reported injury were calculated for single predictors and risk models. Case-control and principal component analyses (PCA) were conducted to elucidate confounders and identify risk factor clusters, respectively. Receiver operating characteristic analysis was used to test the precision of a risk factor cluster to identify pain points and functional difficulties. Results: Sociodemographic, individual, and lifestyle factors were strongly associated with higher odds of injury. Increases in fibrinogen and C-reactive protein were significantly associated with all risk groups. Membership to the high-risk group (age over 40, obesity, no muscle-strengthening activities, sedentary lifestyle, and low back pain) predicted at least one functional difficulty with 67.4% sensitivity and 87.2% specificity. In the injury group, bone turnover markers were higher, yet confounded by age, and there was a significantly higher prevalence of self-reported osteoporosis compared to the control. In males, low testosterone was associated with injury, and high estradiol was associated with pain and functional difficulties. In females, high follicle-stimulating hormone was associated with functional difficulties. PCA revealed four high-risk profiles, with markers and activities showing distinct loadings. Conclusions: A comprehensive approach to injury risk assessment should consider the nexus of aging, lifestyle, and chronic disease to enhance tailored injury prevention strategies, fostering safe and effective physical activity participation and reducing the burden of musculoskeletal disorders.

Composite Biomarkers, Behavioral Symptoms, and Comorbidities in Axial Low Back Pain: A Systematic Review

PURPOSE

Proinflammatory cytokines play a critical role in chronic inflammation and pain and contribute to behavioral symptoms (depressive symptoms, anxiety, fatigue, sleep disturbance) and comorbidities (diabetes, cardiac diseases, cancer). Evidence is lacking on the specific proinflammatory cytokines associated with these behavioral symptoms/comorbidities co-occurring with axial low back pain (aLBP). This review aimed to systematically analyze the following: (1) specific proinflammatory cytokines associated with aLBP in adults, (2) associations among proinflammatory cytokines and behavioral symptoms in aLBP, and (3) relationships among proinflammatory cytokines and comorbidities in aLBP, to develop a new clinical framework for future diagnostic and intervention targets for patients with aLBP.

METHODS

Electronic databases, including PubMed/MEDLINE, ProQuest Nursing & Allied Health Source, and CINAHL Complete (EBSCO) were searched for the period January 2012 to February 2023. Eligible studies included cross-sectional, case-control, longitudinal, and cohort studies in which proinflammatory cytokines were reported in adults above 18 years with aLBP. Intervention studies and randomized controlled trails were excluded. The Joanna Briggs Institute (JBI) criteria were used for quality evaluation.

RESULTS

Findings from 11 studies showed 3 proinflammatory cytokines associated with pain intensity in adult patients with aLBP: C-Reactive Protein (CRP), Tumor Necrosis Factor (TNF-α), and Interleukin (IL-6). Some studies assessed associations between proinflammatory cytokines and depressive symptoms; none explored the association of proinflammatory cytokines with fatigue, anxiety, sleep disturbance, or comorbidities (diabetes, cardiac diseases, and cancer) in aLBP.

CONCLUSIONS

Proinflammatory cytokines in aLBP can serve as composite biomarkers for pain, associated symptoms, and comorbidities and may serve as a target for future interventions. There is need for well-designed studies assessing associations among chronic inflammation, behavioral symptoms, and comorbidities.

The importance of inflammatory biomarkers in non-specific acute and chronic low back pain: a systematic review

OBJECTIVE

The purpose of this study was to systematically review the evidence on inflammatory biomarkers as analytic predictors of non-specific low back pain (NsLBP). Low back pain (LBP) is the number one cause of disability globally, posing a major health problem that causes an enormous social and economic burden, and there is an increasing interest on the importance of biomarkers in quantifying and even emerge as potential therapeutic tools to LBP.

METHODS

A systematic search was conducted on July 2022 in Cochrane Library, MEDLINE and Web of Science for all the available literature. Cross-sectional, longitudinal cohort or case-control studies that evaluated the relationship between inflammatory biomarkers collected from blood samples and low back pain in humans were considered eligible for inclusion, as well as prospective and retrospective studies.

RESULTS

The systematic database search resulted in a total of 4016 records, of which 15 articles were included for synthesis. Sample size comprised a total of 14,555 patients with LBP (acute LBP (n = 2073); chronic LBP (n = 12482)) and 494 controls. Most studies found a positive correlation between classic pro-inflammatory biomarkers and NsLBP, namely C-reactive protein (CRP), interleukin 1 (IL-1) and IL-1β, interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). On the other hand, anti-inflammatory biomarker interleukin 10 (IL-10) demonstrated a negative association with NsLBP. Four studies have made direct comparisons between ALBP and CLBP groups regarding their inflammatory biomarkers profile.

CONCLUSIONS

This systematic review found evidence of increased levels of pro-inflammatory biomarkers CRP, IL-6 and TNF-α and decreased levels of anti-inflammatory biomarker IL-10 in patients with LBP. Hs-CRP was not correlated with LBP. There is insufficient evidence to associate these findings with the degree of pain severity or the activity status of the lumbar pain over time.

Investigation of Vitamin D Levels and the Effects of Being an Agricultural Worker on Etiology and Night Pain in Children and Adolescents With Chronic Low Back Pain

Objective: Chronic low back pain in children is a condition that should be investigated. In this study, we examined the effects of agricultural work on imaging results, risk factors, night pain, and vitamin D levels in children and adolescents with chronic low back pain.

Material and methods: The study included 133 patients who presented to the Physical Medicine and Rehabilitation and Neurosurgery outpatient clinics with low back pain that had lasted more than three months. The patients were evaluated based on the duration of their low back pain, the presence of night pain, a family history of low back pain, their employment status, local or radicular pain, and their body mass index (BMI). A physical examination was carried out to look into the etiologies of low back pain. Appropriate imaging, such as x-ray radiography, magnetic resonance imaging (MRI), and computed tomography (CT), was performed for the patients. Blood samples were collected from patients to assess inflammatory pathologies and vitamin D levels.

Results: The 133 patients in the study ranged in age from seven to 16 years, with a mean age of 14.3 + 1.9 years. Further, 60.2% (n = 80) of the cases were male, while 39.8% (n = 53) were female. Imaging revealed findings in 59.4% of the patients. In 97.7% of the participants, D hypovitaminosis was detected. There was no significant relationship between the patients’ imaging findings and vitamin D deficiency, family history, BMI, and employment status (p = 0.441, 0.147, 0.082, 0.605). The relationship between family history, employment status, and night pain was statistically significant (p < 0.001). There was no statistically significant relationship between night pain and vitamin D deficiency (p = 0.667).

Conclusion: Mechanical strain due to agricultural work and family history was found to be associated with night pain in patients with chronic low back pain in our study. The most important finding of this study is that night pain, which is considered a red flag, can occur in both inflammatory pathologies and situations causing mechanical low back pain, and risk factors should be thoroughly investigated. Studies with patients who have sufficient vitamin D will help to clarify the relationship between chronic low back pain and vitamin D.

Insights into the pleiotropic relationships between chronic back pain and inflammation-related musculoskeletal conditions: rheumatoid arthritis and osteoporotic abnormalities

ABSTRACT

The ageing process includes the development of debilitating musculoskeletal (MSK) conditions, including chronic back pain (CBP), rheumatoid arthritis (RA), and osteoporosis (OP). The mechanisms involved in the genetic-epidemiological relationships between these MSK phenotypes are controversial and limited and thus require clarification, in particular, between CBP and the other MSK phenotypes. A cross-sectional statistical analysis was conducted using Europeans from the UK Biobank data collection, including 73,794 CBP, 4883 RA, and 7153 OP cases as well as 242,216 calcaneus bone mineral density scores. C-reactive protein (CRP) was measured for 402,165 subjects in this sample. Genetic correlations were assessed to evaluate shared genetic background between traits. Mendelian randomization was performed to assess a causal relationship between CBP and RA and OP along with other risk factors, such as CRP. Colocalization analysis was conducted to identify shared pleiotropic regions between the examined traits. Bayesian modelling was performed to determine a potential pathway that may explain the interrelationships among these traits. Mendelian randomization analyses revealed that CRP causally predicts CBP only (β = 0.183, 95% CI = 0.077-0.290, P -value = 0.001). Horizontally pleiotropy appeared to explain the relationship between CBP and RA and OP. Through colocalization analysis, several genomic regions emerged describing common genetic influences between CBP and its proposed risk factors, including HLA-DQA1/HLA-DQB1, APOE , SOX5, and MYH7B as well as Histone 1 genes. We speculate that among other factors, CBP and its MSK comorbidities may arise from common inflammatory mechanisms. Colocalized identified genes may aid in advancing or improving the mode of treatment in patients with CBP.

No associations between C-reactive protein and spinal pain trajectories in children and adolescents (CHAMPS study-DK)

Preliminary evidence points to a link between C-reactive protein (CRP) and spinal pain in adults. However, there is a paucity of research in younger populations. Therefore, we aimed to determine associations between CRP and spinal pain in childhood and adolescence. We identified trajectories of spinal pain from childhood to adolescence and investigated the associations between CRP and trajectory subgroups. Six- to 11-year-old children from 13 primary schools, were followed from October 2008 and until 2014. High-sensitivity CRP collected at baseline (2008) was measured using serum samples. The outcome was the number of weeks with non-traumatic spinal pain between November 2008 and June 2014. We constructed a trajectory model to identify different spinal pain trajectory subgroups. The associations between CRP and spinal pain trajectory subgroups were modelled using mixed-effects multinominal logistic regression. Data from 1556 participants (52% female), with a mean age of 8.4 years at baseline, identified five spinal pain trajectory subgroups: "no pain" (55.3%), "rare" (23.7%), "rare, increasing" (13.6%), "moderate, increasing" (6.1%), and "early onset, decreasing" (1.3%). There were no differences in baseline high-sensitivity CRP levels between spinal pain trajectory subgroups. Thus, the heterogeneous courses of spinal pain experienced were not defined by differences in CRP at baseline.

The effectiveness of weight loss programs for low back pain: a systematic review

BACKGROUND

Low back pain has been associated with obesity or with being overweight. However, there are no high-quality systematic reviews that have been conducted on the effect of all types of weight loss programs focused on individuals with low back pain. Therefore, the present systematic review aims to evaluate the effectiveness of weight loss programs in reducing back pain and disability or increasing quality of life for individuals experiencing low back pain.

MATERIALS AND METHODS

Searches for relevant studies were conducted on CINAHL, Web of Science, Ovid Medline, Ovid Embase and AMED. Studies were included if they were randomized controlled trials, non-randomized studies of intervention or quasi-experimental designs evaluating a weight loss program for persons with low back pain aimed at decreasing back pain and disability. The Effective Public Health Practice Project (EPHPP) Quality Assessment Tool was used to evaluate individual studies and GRADE was used to summarize the quality of the evidence. The review was prospectively registered; PROSPERO#: CRD42020196099.

RESULTS

Eleven studies (n = 689 participants) including one randomized controlled trial, two non-randomized studies of intervention and eight single-arm studies were included (seven of which evaluated bariatric surgery). There was low-quality evidence that a lifestyle intervention was no better than waitlist for improving back pain and very low-quality evidence from single-arm studies that back pain improved from baseline after bariatric surgery. Most studies included were of poor quality, primarily due to selection bias, uncontrolled confounders, and lack of blinding, limiting the quality of evidence.

CONCLUSION

There is very low-quality evidence that weight loss programs may improve back pain, disability, and quality of life in patients with LBP, although adherence and maintenance are potential barriers to implementation.

Major dietary patterns in relation to chronic low back pain; a cross-sectional study from RaNCD cohort

Background

Chronic low back pain (LBP) is the most common musculoskeletal pain that affects a person’s daily activities. This present study aimed at evaluating the relationship between major dietary pattern and Chronic LBP.

Methods

This cross-sectional analysis was examined 7686 Kurdish adults. The RaNCD cohort study physician diagnosed chronic LBP. Dietary patterns were derived using principal component analysis. The three identified dietary patterns derived were named: 1) the vegetarian diet included vegetables, whole grain, legumes, nuts, olive, vegetable oil, fruits, and fruit juice; 2) high protein diet related to higher adherence to red and white meat, legumes, nuts, and egg; and 3) energy-dense diet characterized with higher intake of salt, sweet, dessert, hydrogenated fat, soft drink, refined grain, tea, and coffee. Dietary pattern scores were divided into tertiles. Binary logistic regression in crude, adjusted odds ratios (OR) and 95% confidence intervals (CI) were used to determine this association.

Results

Twenty-two per cent of participants had chronic LBP. Higher adherence to high protein dietary pattern was inversely associated with chronic LBP in crude (OR: 0.79, 95% CI: 0.69–0.9) and adjusted model (for age, sex, smoking, drinking, diabetes, physical activity, body mass index, and waist circumference) (OR: 0.84, 95% CI: 0.72–0.97). In addition, after controlling for the mentioned potential confounders, participants in the highest category of energy dense diet were positively associated with chronic LBP compared with those in the lowest category (OR: 1.13, 95% CI: 1.01–1.32).

Conclusions

Higher adherence to the high protein diet was inversely related to chronic LBP prevalence. In addition, we found that following energy dense diet was positively associated with chronic LBP.

Is adiposity associated with back and lower limb pain? A systematic review

BACKGROUND

Back and lower limb pain have a major impact on physical function and quality of life. While obesity is a modifiable risk factor for musculoskeletal pain, the role of adiposity is less clear. This systematic review aimed to examine the relationship between both adiposity and its distribution and back and lower limb pain.

METHODS

A systematic search of electronic databases was conducted to identify studies that examined the association between anthropometric and/or direct measures of adiposity and site specific musculoskeletal pain. Risk of bias was assessed and a best evidence synthesis was performed.

RESULTS

A total of 56 studies were identified which examined 4 pain regions, including the lower back (36 studies), hip (two studies), knee (13 studies) and foot (eight studies). 31(55%) studies were assessed as having low to moderate risk of bias. 17(30%) studies were cohort in design. The best evidence synthesis provided evidence of a relationship between central adiposity and low back and knee pain, but not hip or foot pain. There was also evidence of a longitudinal relationship between adiposity and the presence of back, knee and foot pain, as well as incident and increasing foot pain.

CONCLUSIONS

This systematic review provides evidence of an association between both body fat and its central distribution and low back and knee pain, and a longitudinal relationship between adiposity and back, knee and foot pain. These results highlight the potential for targeting adiposity in the development of novel treatments at these sites.

The effect of obesity on pain severity and pain interference

Aim: Obesity is one of the most prevalent comorbidities associated with chronic pain, which can severely interfere with daily living and increase utilization of clinical resources. We hypothesized that a higher level of obesity, measured by BMI, would be associated with increased pain severity (intensity) and interference (pain related disability). Materials & methods: Participant data was pulled from a multisite chronic pain outpatient database and categorized based on BMI. Results: A total of 2509 patients were included in the study. We found significant differences between BMI groups for all pain severity scores (worst, least, average, current) and total pain interference score. Obese patients had significantly higher scores than normal weight patients. Conclusion: We found obesity to be associated with increased pain severity and pain interference.

Vitamin D Deficiency and Molecular Changes in Circulating MicroRNAs in Older Adults with Lower Back Pain

Background

MicroRNAs play an essential role in regulating pain processing within a wide range of clinical pain disorders.

Objectives

The present study aimed to evaluate the role of circulating miRNAs as biomarkers of lower back pain in older adults. In addition, the correlation between miRNAs and other related cofounders such as muscle function, adiposity, malnutrition, and Ca and vitamin D intake was assessed.

Methods

A total of 110 older subjects with an age range of 40-60 years were included in this study. The participants were classified according to a modified Oswestry lower back pain disability questionnaire (OSW) into subjects with minimal LBP (n = 40; LBP score: 0-20%), moderate LBP (n = 35; LBP score: 20-40%), and severe LBP (n = 35; LBP score: 41-60%). RT-PCR and immunoassays were used to study the circulating miRNA profile, vitamin D status, and CRP, IL-6, TNF-α, s-Ca, s-BAP, s-OC, and s-NTX levels. In addition, malnutrition and muscle performance were estimated in all subjects as other factors related to LBP.

Results

In this study, normal LBP-OSW cutoff values (8.96 ± 3.6) were reported in 36.4% of the total population, whereas 63.6% of the population had higher LBP-OSW scores, classified as follows: 31.8% with moderate LBP (LBP-OSW score: 31.4 ± 9.1) and 31.8% with severe LBP (LBP-OSW score: 54.9 ± 14.6). Four circulating miRNAs, namely, miR-146a, miR-558, miR-155, and miR-124a, as biomarkers of the intensity of back pain were identified in all participants. In subjects with moderate to severe LBP, the expression levels of miR-146a and miR-558 were significantly reduced and those of miR-155 and miR-124a were significantly increased compared to subjects with minimal LBP scores. Subjects with moderate to severe LBP showed a significant increase in adiposity markers, lower PA, muscle performance, malnutrition, and lower Ca and vitamin D intake compared to normal controls. In addition, serum levels of vitamin D and circulated plasma markers of inflammation and bone metabolism such as CRP, IL-6, TNF-α, s-Ca, s-BAP, s-OC, and s-NTX were significantly reduced in severe LBP cases compared to those with minimal LBP scores. The expressed circulating miRNAs were significantly associated with the measured muscle performance, adiposity, PA score, inflammation, and bone metabolism cofounders in subjects with higher LBP-OSW scores. The expressed miRNAs, along with other LBP cofounders, were significantly associated with ∼63.9-86.4% of the incidence of LBP in older adults.

Conclusions

In older adults with vitamin D deficiency, the severity of LBP was significantly associated with the expression of circulating miRNAs, adiposity, bone metabolism, inflammation, and muscle performance. In addition, the expressed miRNAs, along with other LBP cofounders, were significantly associated with ∼63.9-86.4% of the incidence of LBP in older adults. These results suggest the possibility of using microRNAs as therapeutics to alleviate established pain and as biomarkers in old adults with painful conditions.

Circulating inflammatory biomarkers in adolescents: evidence of interactions between chronic pain and obesity

Introduction

The negative effects of chronic pain and obesity are compounded in those with both conditions. Despite this, little research has focused on the pathophysiology in pediatric samples.

Objective

To examine the effects of comorbid chronic pain and obesity on the concentration of circulating inflammatory biomarkers.

Methods

We used a multiple-cohort observational design, with 4 groups defined by the presence or absence of obesity and chronic pain: healthy controls, chronic pain alone, obesity alone, as well as chronic pain and obesity. Biomarkers measured were leptin, adiponectin, leptin/adiponectin ratio (primary outcome), tumor necrosis factor-alpha, interleukin 6, and C-reactive protein (CRP).

Results

Data on 125 adolescents (13-17 years) were analyzed. In females, there was an interaction between chronic pain and obesity such that leptin and CRP were higher in the chronic pain and obesity group than in chronic pain or obesity alone. Within the chronic pain and obesity group, biomarkers were correlated with worsened pain attributes, and females reported worse pain than males. The highest levels of interleukin 6 and CRP were found in youth with elevated weight and functional disability. We conclude that in adolescents, chronic pain and obesity interact to cause dysregulation of the inflammatory system, and this effect is more pronounced in females.

Conclusion

The augmented levels of inflammatory biomarkers are associated with pain and functional disability, and may be an early marker of future pain and disability.

Shift work, low-grade inflammation, and chronic pain: a 7-year prospective study

Objectives

We investigated prospective associations of shift work with chronic pain and C‐reactive protein (CRP), an indicator of inflammation. Furthermore, we elucidated CRP as a possible mediator and/or moderator of effects of shift work on pain.

Methods

Data from a 7 years follow‐up study were analyzed (N = 2323). Shift work and chronic pain of “neck/shoulder”, “arm/hand”, “upper back”, “low back”, “hip/leg/feet”, and “other regions” were measured by questionnaires. “Chronic widespread pain”, “number of chronic pain sites”, and “any chronic pain” were computed. CRP was measured in serum samples. Logistic and Poisson regressions were conducted. Mediation was assessed by casual mediation analyses and moderation by the Relative Excess Risk due to Interaction (RERI).

Results

Shift work was not associated with any chronic pain variable and no mediation was detected. CRP was associated with low back pain, hip/leg pain, and “number of pain sites”, and also with the combination of shift work and CRP of 1–2.99 mg/L (compared to: no shiftwork and CRP < 1). Additionally, shiftwork and CRP 1–2.99 mg/L was associated with risk of “any chronic pain” (OR: 1.76, 95% CI: 1.12, 2.85), which was not associated with CRP alone. Moderation analyses suggested the risks for “any chronic pain” and “number of pain regions” increased when individuals with elevated CRP worked shifts—beyond what the separate effects of CRP and shift would suggest.

Conclusions

We found no evidence of shift work in general affecting CRP or chronic pain. However, shift work and elevated CRP combined may influence chronic pain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-020-01626-2.

Multi-trajectory analysis of C-reactive protein and low back pain from adolescence to early adulthood

PURPOSE

To identify low back pain (LBP) trajectories from early adolescence through to early adulthood and to investigate whether sustained levels of elevated subclinical C-reactive protein (CRP) are linked with these LBP trajectories.

METHODS

We analysed longitudinal data from 1513 participants who were enrolled in the Raine Study cohort. Data on LBP with impact on daily living and CRP were collected at the ages of 14, 17, 20, and 22. We constructed group-based trajectory models to identify discrete trajectories of LBP with impact. We then evaluated how the CRP trajectories and the LBP with impact trajectories evolved jointly over time using a multi-trajectory analysis.

RESULTS

The model identified three LBP trajectories. One subgroup included almost half the participants (46.1%) who had a consistently low probability of LBP. Another subgroup comprising 43.5% of participants had an increasing probability of LBP, while one in ten participants (10.4%) had a decreasing probability of LBP. There were no associations between elevated CRP and LBP trajectory subgroup membership.

CONCLUSION

Although young people follow distinct trajectories of LBP, CRP trajectories do not appear to be a distinguishing factor of the LBP trajectories. Previously reported associations between CRP and LBP may be explained by comorbidity or other factors. Future studies undertaking trajectory analysis should consider comorbidity clusters.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Obesity, the new childhood disability? An umbrella review on the association between adiposity and physical function

The adverse physical impacts of childhood obesity are increasingly being recognized. The objective of this study is to examine relationships between physical function and adiposity in youth. An umbrella review searched seven databases from inception to May 2019 for systematic reviews examining associations between adiposity and physical function in 0-20-year-olds. Findings were synthesized using the International Classification of Functioning, Disability and Health Framework and NHMRC FORM. Seventeen of 21 systematic reviews reported impairments to body function, including cardiorespiratory fitness (CRF), muscle function, balance/coordination, gait biomechanics, pain and injury. Six reviews reported activity restrictions in motor skills, running speed/agility and functional mobility, and two found inverse associations between adiposity and physical health-related quality of life (p-HRQOL). Some causal relationships indicated that adiposity inversely predicted p-HRQOL/CRF and CRF/muscle function inversely predicted adiposity. Assessments of physical function were heterogeneous and impacts on participation in life situations meaningful to the individual were largely unknown. Substantial evidence associates childhood overweight/obesity with reduced physical function. Associations were mainly cross-sectional, with causative evidence for some outcomes. Comprehensive physical function assessments by qualified health professionals are needed, along with targeted interventions to address deficits. Research should further examine causality of relationships, underlying mechanisms and participation challenges in real-life contexts.

Association of Serum Minerals, Vitamin D, Total Protein, and Inflammatory Mediators and Severity of Low Back Pain

BACKGROUND

Low back pain (LBP) is a multifactorial disorder with multiple etiologies, which are not fully understood. In this study, we aimed to evaluate the relationship between serum levels of minerals, total protein, vitamin D (vit D), and inflammatory mediators with LBP and its severity.

MATERIALS AND METHODS

This case-control study was derived from the study nested in the Fasa Cohort Study. Overall, 148 individuals with LBP were compared with 150 individuals without LBP. Blood samples were evaluated for serum protein, iron (Fe), aluminum (Al), copper (Cu), phosphorus, vit D, IL-1B, IL-6, high-sensitive C-reactive protein (HS-CRP), and TNF-alpha. Severity of pain was measured with the McGill and Oswestry questionnaires.

RESULTS

The mean age of participants in the case and control groups was 49.2 ± 6.1 and 47.57 ± 5.85 years, respectively. In the case group, 61 patients (48.8%) were male. The mean serum levels of Fe, Al, vit D, Cu, IL-1B, IL-6, HS-CRP, and TNF-alpha were significantly different between case and control groups (P≤0.05). However, there were no significant differences between studied groups in the term of sex and serum phosphorus (P>0.05). Regarding pain severity, age was correlated with McGill score (r=0.18), body mass index with Oswestry (r=0.21), Fe with McGill (r=-0.15) and Oswestry (r=-0.13), protein with McGill (r=0.32) and Oswestry (r=-0.32), Al with McGill (r=0.56) and Oswestry (r=0.45), IL-1B with McGill (r=0.19) and Oswestry (r=0.13), TNF-alpha with McGill (r=0.34) and Oswestry (r=0.26), IL-6 with Oswestry (r=0.13), HS-CRP with McGill (r=0.60) and Oswestry (r=0.46), and vit D was correlated with McGill (r=0.21) and Oswestry scores (r=0.17). Higher Fe (odds ratio [OR]: 0.99), protein (OR: 0.47), Al (OR: 0.11), and vit D levels (OR: 0.97) were protective against LBP (P<0.001). Higher IL-1B (OR: 1.01), TNF-alpha (OR: 1.03), and HS-CRP (OR: 1.0003) presented as risk factors for LBP (P<0.001).

CONCLUSION

Our study revealed except phosphorous, all the serum levels minerals and inflammatory markers was significantly different in LBP patients compared to healthy individuals. Also, in the LBP patients, serum levels of Fe, total protein, Al, and vit D aside to inflammatory mediators (i.e., IL-1B, TNF-alpha, and HS-CRP) shows a marked association with severity of LBP.

The effect of obesity on pain and disability in chronic shoulder pain patients

OBJECTIVE

This study aimed to investigate the relationship between chronic shoulder pain and the increase in BMI.

METHODS

A prospective, cross-sectional study design was adopted for the study. Two hundred and eighty-five patients with chronic shoulder pain were evaluated for eligibility. A total of 94 patients were excluded from the study. The 191 remaining volunteers filled out a questionnaire (Pain (VAS), Shoulder Pain and Disability Index (SPADI)) and weight, height, C-reactive protein (CRP) results and 1-hour-rate of erythrocyte sedimentation rate (ESR) were measured. The participants were dived into the normal weight, overweight or obese group, considering the obesity classification defined by the World Health Organization (WHO).

RESULTS

A statistically significant correlation was found between the increase in BMI and pain (VAS), SPADI (pain, activity and total) and ESR. Although there was no statistically significant difference between the normal weight and overweight groups in all parameters, there was a statistically significant difference between the obese group and other groups.

CONCLUSIONS

Shoulder pain may associated with obesity and we recommend the addition of weight control to the treatment of patients with shoulder 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.

Altered Gut Microbiota Composition Is Associated With Back Pain in Overweight and Obese Individuals

Background: Back pain is the leading cause of disability worldwide and is associated with obesity and chronic low-grade inflammation. Alterations in intestinal microbiota may contribute to the pathogenesis of back pain through metabolites affecting immune and inflammatory responses. Aims and Methods: We compared the gut microbiota composition in a cohort of 36 overweight or obese individuals with or without self-reported back pain in the preceding month. Participants were characterized for anthropometry; bone health; metabolic health; inflammation; dietary intake; and physical activity. Results: Demographic, clinical, biochemical characteristics, diet and physical activity were similar between participants with (n = 14) or without (n = 22) back pain. Individuals with back pain had a higher abundance of the genera Adlercreutzia (p = 0.0008; FDR = 0.027), Roseburia (p = 0.0098; FDR = 0.17), and Uncl. Christensenellaceae (p = 0.02; FDR = 0.27) than those without back pain. Adlercreutzia abundance remained higher in individuals with back pain in the past 2 weeks, 6 months, and 1 year. Adlercreutzia was positively correlated with BMI (rho = 0.35, p = 0.03), serum adipsin (rho = 0.33, p = 0.047), and serum leptin (rho = 0.38, p = 0.02). Conclusions: Our findings suggest that back pain is associated with altered gut microbiota composition, possibly through increased inflammation. Further studies delineating the underlying mechanisms may identify strategies for lowering Adlercreutzia abundance to treat back pain.

Adiponectin receptor 1 gene is potentially associated with severity of postoperative pain but not cancer pain

Adiponectin is an adipose tissue-derived cytokine that exerts its antiinflammatory effects by binding to 2 adiponectin receptors, adiponectin receptor 1 (ADIPOR1) and adiponectin receptor 2 (ADIPOR2). However, the role of these adiponectin receptors on inflammatory pain remains unclear. We investigated the association between single nucleotide polymorphisms (SNPs) of these genes and inflammatory pain, such as postoperative pain and cancer pain.We analyzed 17 SNPs of the ADIPOR1 gene and 27 SNPs of the ADIPOR2 gene in 56 adult patients with postlaparotomy pain. We compared these genotypes with pain intensity and opioid consumption, adjusting for multiple testing. We analyzed the genotypes of 88 patients with cancer pain and examined the association of the relevant SNP(s) with pain intensity and opioid consumption.One variant of the ADIPOR1 gene (rs12045862) showed significant association with postoperative pain intensity; patients with minor allele homozygote (n = 7) demonstrated significantly worse pain intensity than that of combined patient group exhibiting major allele homozygote or the heterozygote (n = 49; Mann-Whitney test, P < .00002), although their opioid consumptions were comparable. Cancer pain intensity between minor allele homozygote patients (n = 7) and other 2 genotype patients (n = 81) were comparable.The rs12045862 SNP of the ADIPOR1 gene was associated with postoperative pain but not cancer pain. This might result from functional alteration of the ADIPOR1 signalling pathways, which influence the inflammatory process. ADIPOR1 may be a novel potential target for developing analgesics of postoperative pain.

Professional barriers and facilitators to using stratified care approaches for managing non-specific low back pain: a qualitative study with Canadian physiotherapists and chiropractors

Background

Recent clinical practice guidelines for the management of non-specific low back pain (LBP) recommend using stratified care approaches. To date, no study has assessed barriers and facilitators for health professionals in using stratified care approaches for managing non-specific LBP in the Canadian primary care setting. This study aimed to identify and contrast barriers and facilitators to using the stratified care approaches for non-specific LBP among Canadian physiotherapists and chiropractors.

Methods

Individual telephone interviews, underpinned by the Theoretical Domains Framework (TDF), explored beliefs and attitudes about, and identified barriers and facilitators to the use of stratified care approaches for managing non-specific LBP in a purposive sample of 13 chiropractors and 14 physiotherapists between September 2015 and June 2016. Interviews were digitally recorded, transcribed verbatim and analysed by two independent assessors using directed content analysis.

Results

Three and seven TDF domains were identified as likely relevant for physiotherapists and chiropractors, respectively. Shared key beliefs (and relevant domains of the TDF) for both physiotherapists and chiropractors included: lack of time, cost, and expertise (Environmental Context and Resources); and consulting more experienced colleagues and chronic patients with important psychological overlay (Social Influences). Unique key domains were identified among physiotherapists: incompatibility with achieving other objectives (Goals), and chiropractors: confidence in using stratified care approaches (Beliefs about Capabilities); intention to use stratified care approaches (Intentions); awareness and agreement with stratified care approaches (Knowledge); assessment of readiness for change and intentional planning behaviour (Behavioural Regulation); and improving the management of non-specific LBP patients and the uptake of evidence-based practice (Beliefs about Consequences).

Conclusions

Several shared and unique barriers and facilitators to using the stratified care approaches for non-specific LBP among Canadian physiotherapists and chiropractors were identified. Findings may help inform the design of tailored theory-based knowledge translation interventions to increase the uptake of stratified care approaches in clinical practice.

The association between insomnia, c-reactive protein, and chronic low back pain: cross-sectional analysis of the HUNT study, Norway

BACKGROUND AND AIMS

Chronic low back pain (chronic LBP) is the number one cause for years lived with disability among 301 diseases and injuries analyzed by The Global Burden of Disease study 2013. Insomnia is highly prevalent among people with chronic LBP. To explain the sleep-pain relationship, theoretical models propose that insomnia symptoms may be associated with increased basal inflammation, operationalized as c-reactive protein (CRP) and lead to further pain and disrupted sleep. We aimed to determine the associations between insomnia, chronic LBP, and inflammation (operationalized as CRP), whilst controlling for age, body mass index, smoking, physical activity, depression, anxiety and osteoarthritis.

METHODS

A cross-sectional analysis of the third Nord-Trøndelag Health Study (2006-2008), a rural population survey of 50,666 participants in Norway aged 20-96 years. Insomnia (dichotomous) was defined according to the Diagnostic and Statistical Manual of Mental Disorders 5th Edition, and chronic LBP (dichotomous) as low back pain or stiffness lasting at least 3 months. Data for CRP were obtained from non-fasting serum samples and assessed via latex immunoassay methodology. We excluded participants with the following self-reported chronic somatic diseases: chronic heart failure, chronic obstructive pulmonary disease, rheumatoid arthritis, fibromyalgia or ankylosing spondylosis. Possible associations between presence of insomnia and presence of chronic LBP (dependent), and the level of CRP and presence of chronic LBP (dependent), were assessed using logistic regression models. The possible association between insomnia and CRP (dependent) was assessed using linear regression. Multivariable analyses were conducted adjusting for confounders stated in our aim that achieved p ≤ 0.2 in univariate regressions. We performed stratified analyses for participants with "Normal" (<3 mg/L) "Elevated" (3-10 mg/L) and "Very High" (>10 mg/L) levels of CRP.

RESULTS

In our total included sample (n = 30,669, median age 52.6, 54% female), 6.1% had insomnia (n = 1,871), 21.4% had chronic LBP (n = 6,559), and 2.4% had both (n = 719). Twenty four thousand two hundred eighty-eight (79%) participants had "Normal" CRP, 5,275 (17%) had "Elevated" CRP, and 1,136 (4%) had "Very High" CRP. For participants with "Normal" levels of CRP, insomnia was associated with higher levels of CRP (adjusted B = 0.04, 95%CI [0.00-0.08], p = 0.046), but not for people with "Elevated" or "Very High" levels of CRP. There was an association between CRP and presence of chronic LBP in the total sample (adjusted OR = 1.01, [1.00-1.01], p = 0.013) and for people with "Normal" CRP (1.05, [1.00-1.10, p = 0.034]. Insomnia was associated with the presence of chronic LBP in the total sample (adjusted OR = 1.99, 95%CI [1.79-2.21], <0.001) and for people with "Normal", "Elevated" and "Very High".

CONCLUSIONS

Individuals with insomnia have twice the odds of reporting chronic LBP. Insomnia, CRP and chronic LBP appear to be linked but the role of CRP appears to be limited. Longitudinal studies may help further explore the causal inference between insomnia chronic LBP, and inflammation.

IMPLICATIONS

Given the strong relationship between insomnia and chronic LBP, screening and management of comorbid insomnia and chronic LBP should be considered in clinical practice. Further longitudinal studies are required to explore whether the presence of insomnia and increased inflammation affects the development of chronic LBP.

Sex differences in the association of metabolic syndrome with low back pain among middle-aged Japanese adults: a large-scale cross-sectional study

BACKGROUND

Although some recent studies have indicated an association between metabolic syndrome (MetS) and musculoskeletal disease, little is known about the association of MetS with low back pain (LBP). The present study aimed to investigate sex differences in the association of MetS and the clustering of MetS components with LBP among middle-aged Japanese individuals.

METHODS

Study subjects were 45,192 adults (30,695 men, 14,497 women) aged 40-64 years who underwent annual health checkups conducted from April 2013 to March 2014. MetS was defined according to the criteria of the Examination Committee of Criteria for MetS in Japan as abdominal obesity plus at least two of dyslipidemia, high blood pressure, or high blood glucose. Information on LBP and health-related lifestyles were collected using a self-administered questionnaire. Logistic regression modeling was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP.

RESULTS

After adjusting for age and lifestyle factors, the OR of MetS for LBP was 1.15 (95% CI 0.95-1.40) in men and 2.16 (95% CI 1.32-3.53) in women. Compared to subjects without abdominal obesity, the presence of abdominal obesity significantly increased the OR for LBP among men (abdominal obesity only: OR 1.34, 95% CI 1.02-1.76; abdominal obesity plus one component: OR 1.24, 95% CI 1.01-1.52; abdominal obesity plus two or more components: OR 1.26, 95% CI 1.02-1.55). Among women, adding other components of MetS to abdominal obesity significantly increased ORs for LBP (abdominal obesity only: OR 1.70, 95% CI 0.94-3.08; abdominal obesity plus one component: OR 1.66, 95% CI 1.06-2.60; abdominal obesity plus two or more components: OR 2.30, 95% CI 1.41-3.78).

CONCLUSIONS

This large-scale cross-sectional study indicated that MetS was significantly associated with LBP among women only and that a sex-difference existed in the association between the clustering of MetS components and LBP. Clustering of MetS components by sex may need to be considered for the prevention of LBP, although further prospective studies are needed to clarify the causality.

The interplay between sleeplessness and high-sensitivity C-reactive protein on risk of chronic musculoskeletal pain: longitudinal data from the Tromsø Study

Study Objectives

To examine independent associations of sleeplessness and high-sensitivity C-reactive protein (hsCRP) with risk of chronic musculoskeletal pain, and to explore the joint effect of sleeplessness and hsCRP on risk of chronic musculoskeletal pain.

Methods

A population-based prospective study of 3214 women and 3142 men (mean age: 55.4, range: 32–87) without severe chronic musculoskeletal pain and with hsCRP ≤ 10 mg/L at baseline in 2007–2008. Modified Poisson regression was used to calculate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for any chronic musculoskeletal pain and chronic widespread pain (CWP) at follow-up in 2015–2016 associated with self-reported sleeplessness and hsCRP at baseline.

Results

Compared with persons without sleeplessness, women and men reporting often/or always sleeplessness had RRs of CWP of 2.53 (95% CI: 1.94–3.29) and 2.48 (95% CI: 1.63–3.77), respectively. There was no clear association between hsCRP and risk of any chronic musculoskeletal pain or CWP. Joint effect analyses using persons without sleeplessness and with a hsCRP < 1.00 mg/L as the reference gave RRs for chronic musculoskeletal pain of 1.73 (95% CI: 1.26–2.37) for those with often/always sleeplessness and hsCRP < 1.00 mg/L; 1.01 (95% CI: 0.78–1.32) for those without sleeplessness and hsCRP ≥3.00 mg/L; and 2.47 (95% CI: 1.79–3.40) if they had both often/always sleeplessness and hsCRP ≥ 3.00 mg/L. The corresponding RRs for CWP were 1.89 (95% CI: 1.27–2.83), 0.96 (95% CI: 0.68–1.37), and 2.83 (95% CI: 1.91–4.20), respectively.

Conclusions

These results suggest that there is an interplay between sleeplessness and hsCRP on risk of any chronic musculoskeletal pain and CWP.

Health indicators and costs among outpatients according to physical activity level and obesity

OBJECTIVE

How biochemical variables influence the costs of the Brazilian National Healthcare System, according to body composition and physical activity.

METHODS

Participated in this study 168 patients. Biochemical variables were glucose, triglycerides, total cholesterol, high, low, very low density lipoprotein and C-reactive protein (CRP). For the cost analysis the medical records was analyzed. Physical activity was assessed through questionnaire. Body adiposity was assessed by body mass index. Four groups were defined according body adiposity and physical activity.

RESULTS

The active obese group had higher values of very low density lipoprotein and triglycerides when compared to the inactive obese. The non-obese inactive group had lower values of non-high density lipoprotein compared to the inactive obese. The non-obese active group presented lower insulin value when compared to the inactive obese. The inactive obese group presented higher values in the CRP when compared to the non-obese active and inactive groups when compared to non-obese and active obese group. There was a positive correlation between insulin, glucose, CRP and drug and total costs.

CONCLUSIONS

Biochemical variables were different according to body composition and physical activity. Insulin, glucose and CRP were related to cost in drugs and total costs.

Vitamin D supplementation may improve back pain disability in vitamin D deficient and overweight or obese adults

Back pain is currently the greatest cause of disability worldwide, and there are very limited therapeutic options available. Vitamin D deficiency and obesity are both risk factors for back pain. The few randomised controlled trials examining the effects of vitamin D supplementation on back pain have methodological limitations and largely include non-vitamin D deficient participants. Thus, the aim of this study was to determine whether vitamin D supplementation improves back pain symptoms in vitamin D deficient and overweight or obese, otherwise healthy adults. Sixty-five overweight or obese adults (BMI ≥ 25 kg/m²) with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] concentrations ≤50 nmol/L) were randomised to a bolus oral dose of 100,000 IU followed by 4000 IU cholecalciferol/day or matching placebo for 16 weeks. We measured 25(OH)D concentrations (chemiluminescent immunoassays) and self-reported back pain (Chronic Pain Grade Questionnaire) before and after the intervention. Lifestyle habits including sun exposure, physical activity, and diet were collected using questionnaires. Fifty-four participants completed the study, of which 49 had complete data for back pain and were included in the present analyses (31 M/18 F; mean ± SD age: 31.8 ± 8.9 years; BMI: 31.1 ± 4.5 kg/m²). After the 16-week intervention, 25(OH)D levels increased significantly with vitamin D supplementation compared with placebo (55.7 ± 20.9 versus 3.9 ± 14.4 nmol/L, respectively, p < 0.001). There were no significant differences between vitamin D and placebo groups in change in back pain intensity or disability scores (all p > 0.05). However, in those with 25(OH)D concentrations <30 nmol/L at baseline (n = 20), there was a significantly greater reduction in back pain disability scores in the vitamin D group compared with placebo, after adjusting for important covariates known to affect vitamin D status and/or back pain (b [95%CI] = -11.6 [-22.4, -0.8], p = 0.04). Our findings suggest that vitamin D supplementation in overweight or obese and markedly vitamin D deficient adults (25(OH)D <30 nmol/L) may improve back pain disability. Although treating severe vitamin D deficiency is recommended for optimising bone health, this study suggests it may also improve back pain. Hence, testing for vitamin D deficiency in those with back pain who are overweight or obese may be warranted.

The association between pro-inflammatory biomarkers and nonspecific low back pain: a systematic review

BACKGROUND CONTEXT

About 85% of the patients with low back pain seeking medical care have nonspecific low back pain (NsLBP), implying that no definitive cause can be identified. Nonspecific low back pain is defined as low back pain and disability which cannot be linked to an underlying pathology, such as cancer, spinal osteomyelitis, fracture, spinal stenosis, cauda equine, ankylosing spondylitis, and visceral-referred pain. Many pain conditions are linked with elevated serum levels of pro-inflammatory biomarkers. Outcomes of interest are NsLBP and the level of pro-inflammatory biomarkers.

PURPOSE

To unravel the etiology and get better insight in the prognosis of NsLBP, the aim of this study was to assess the association between pro-inflammatory biomarkers and the presence and severity of NsLBP.

STUDY DESIGN

A systematic literature search was made in Embase, Medline, Cinahl, Webof-science, and Google scholar up to January 19th 2017.

METHODS

Included were cross-sectional and cohort studies reporting on patients aged over 18 years with NsLBP, in which one or more pro-inflammatory biomarkers were measured in blood plasma. The methodological quality of the included studies was assessed using the Newcastle Ottawa Scale. A best-evidence synthesis was used to summarize the results from the individual studies, meaning that the included studies were ranked according to the consistency of the findings and according to their methodological quality score using the Newcastle Ottawa Scale.

RESULTS

Included were 10 studies which assessed four different pro-inflammatory biomarkers. For the association between the presence of NsLBP and C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α limited, conflicting and moderate evidence, respectively, was found. For the association between the severity of NsLBP and CRP and IL-6, moderate evidence was found. For the association between the severity of NsLBP and TNF-α and RANTES Regulated on Activation, Normal T Cell Expressed and Secreted conflicting and limited evidence, respectively, was found.

CONCLUSIONS

This study found moderate evidence for (i) a positive association between the pro-inflammatory biomarkers CRP and IL-6 and the severity of NsLBP, and (ii) a positive association between TNF-α and the presence of NsLBP. Conflicting and limited evidence was found for the association between TNF-α and Regulated on Activation, Normal T Cell Expressed and Secreted and severity of NsLBP, respectively.

Neuropsychologists as primary care providers of cognitive health: A novel comprehensive cognitive wellness service delivery model

By virtue of their extensive knowledge base and specialized training in brain-behavior relationships, neuropsychologists are especially poised to execute a unique broad-based approach to overall cognitive wellness and should be viewed as primary care providers of cognitive health. This article will describe a novel comprehensive cognitive wellness service delivery model including cognitive health, anti-aging, lifelong wellness, and longevity-oriented practices. These practice areas include brain-based cognitive wellness, emotional and spiritually centric exploration, and related multimodality health interventions. As experts in mind-body connections, neuropsychologists can provide a variety of evidence-based treatment options, empowering patients with a sense of value and purpose. Multiple areas of clinical therapy skill-based learning, tailor-made to fit individual needs, will be discussed including: brain stimulating activities, restorative techniques, automatic negative thoughts and maladaptive thinking reduction, inflammation and pain management techniques, nutrition and culinary focused cognitive wellness, spirituality based practices and mindfulness, movement and exercise, alternative/complimentary therapies, relationship restoration/social engagement, and trauma healing/meaning. Cognitive health rests upon the foundation of counteracting mind-body connection disruptions from multiple etiologies including inflammation, chronic stress, metabolic issues, cardiac conditions, autoimmune disease, neurological disorders, infectious diseases, and allergy spectrum disorders. Superimposed on these issues are lifestyle patterns and negative health behaviors that develop as ill-fated compensatory mechanisms used to cope with life stressors and aging. The brain and body are electrical systems that can "short circuit." The therapy practices inherent in the proposed cognitive wellness service delivery model can provide preventative insulation and circuit breaking against the shock of illness.

Exploration of the Inter-Relationships Between Obesity, Physical Inactivity, Inflammation, and Low Back Pain

STUDY DESIGN

Retrospective analysis wherein 103 patients were considered, and 76 patients were included: 49 were classified as chronic non-specific low back pain (CNSLBP) (Study group) and 27 had identifiable cases of specific chronic low back pain (LBP) (Control group).

OBJECTIVE

Elucidate markers of systemic inflammation in patients with CNSLBP.

SUMMARY OF BACKGROUND DATA

Mechanisms of LBP are poorly understood. Pro-inflammatory cytokines are increased in obesity and involved with pain modulation; we previously proposed a theoretical model of their mediating role in LBP.

METHODS

Demographic information was acquired via questionnaire, chart review, and blood test data. Univariate analysis identified factors associated with CNSLBP and markers of systemic inflammation. A receiver operating curve and Youden Index were used to select optimal cut-off points for elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Multivariable logistic regression analysis calculated the adjusted strength of relationship between factors that were proposed in our theoretical model for CNSLBP.

RESULTS

Unadjusted CRP was significantly correlated with ESR (R = 0.63, P < 0.0001) and body mass index (BMI) (R = 0.38, P = 0.0015). Physically inactive patients had significantly higher CRP (6.1 vs. 1.2, P = 0.0050). ESR was significantly correlated with number of comorbidities (R = 0.34, P = 0.0047), BMI (R = 0.38, P = 0.0014), and age (R = 0.36, P = 0.0026). Physically inactive patients (10.4 vs. 3.6, P = 0.0001) and females (11.2 vs. 6.4, P = 0.0422) had significantly higher ESR. Adjusted analyses indicated significant relationships between physical inactivity and markers of systemic inflammation (adjusted odds ratios for ESR and CRP: 15.9, P = 0.0380; 15.2, P = 0.0272, respectively), and between elevated CRP and CNSLBP (adjusted odds ratio: 8.0, P = 0.0126).

CONCLUSION

Systemic inflammation may act as a mediator for physical inactivity and obesity in the pathogenesis of CNSLBP.

LEVEL OF EVIDENCE

2.

Low back pain, obesity, and inflammatory markers: exercise as potential treatment

Low back pain is a health issue with significant impact to patients and society. This narrative review aims to synthesize the relationship between obesity, low-grade inflammation and low back pain. It is known that a sedentary lifestyle is a risk factor for obesity and related disorders. The adipose tissue of obese people secretes a range of cytokines of character pro- and anti-inflammatory, with many molecular effects. In addition, pro-inflammatory cytokines are sensitizers of C-reactive protein (CRP), a marker of acute inflammation that can be linked to the musculoskeletal pain sensation individuals with back pain. Another inflammatory marker deserves mention, prostaglandin E2. Prostaglandin E2 is important in the process of triggering actions such as pyrexia, sensation of pain and inflammation, which are exhibited in low back pain condition. The potential for exercises and physical activity to control these mediators and act as a preventative measure for back pain are important because they work as a nonpharmacological strategy to this target audience. There are two types of exercise discussed in this review, the moderate-intensity continuous training and high-intensity interval training.

Adipsin Concentrations Are Associated with Back Pain Independently of Adiposity in Overweight or Obese Adults

Objective: To compare cardiometabolic risk factors including cytokine and adipokine concentrations between individuals with and without back pain. Methods: In 62 overweight/obese adults (BMI ≥ 25 kg/m2; 23F/39M), we collected data on: self-reported back pain; anthropometry [BMI, waist circumference, body composition (dual energy X-ray absorptiometry-DEXA)]; metabolic parameters [fasting glucose; insulin sensitivity (hyperinsulinaemic-euglycaemic clamps)]; cardiovascular parameters (blood pressure, lipids); serum inflammation markers [high-sensitivity C-reactive protein (hsCRP; immunoturbidimetric-assay), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-10 (multiplex-assay)]; and adipokines [leptin, adipsin, resistin, and adiponectin (multiplex-assay)]. Results: Participants who reported having back pain in the past month (n = 24; 39%) had higher BMI (mean ± SD = 33.8 ± 6.3 vs. 30.2 ± 4.1 kg/m2, p = 0.008), fat-mass (39.9 ± 12.3 vs. 33.9 ± 9.8%, p = 0.04), and waist circumference (109.6 ± 16.8 vs. 101.0 ± 9.3 cm, p = 0.01) compared to those without back pain (n = 38; 61%). No differences were observed in cardiometabolic parameters, inflammatory markers, or adiponectin or resistin concentrations. Those reporting back pain had higher adipsin concentrations compared to those without back pain [median (IQR) = 744 (472-2,804) vs. 721 (515-867) ng/ml, p = 0.03], with a trend for higher leptin [5.5 (1.5-24.3) vs. 2.3 (1.5-6.7) ng/ml, p = 0.05], both of which persisted after adjustment for age and sex. Adipsin remained associated with back pain independently of adiposity (BMI, waist, fat-mass, or total %body fat; all p ≤ 0.03). Conclusions: Greater obesity, and higher adipsin and leptin concentrations were observed in those who reported back pain in the past month compared to those without back pain, and adipsin was associated with back pain independently of adiposity. Larger studies are needed to determine if adipsin could be a novel therapeutic target for prevention and/or treatment of back pain.

Integrative Pain Management

Chronic pain is one of the most common conditions seen in the clinic, and it is often one of the most frustrating for both clinicians and patients. This condition stems from common comorbidities, including depression, insomnia, fatigue, and physical deconditioning, which often create barriers to recovery. In addition, chronic pain has had divergent approaches for treatment, including an overemphasis on analgesia and curative treatments while underemphasizing the biopsychosocial needs of those in pain. This article attempts to provide an initial framework for approaching those in pain and initiating patient-centered options to support improvements in pain, function, and self-care.

Fat mass and fat distribution are associated with low back pain intensity and disability: results from a cohort study

Background

Determining the association between body composition and low back pain (LBP) will improve our understanding of the mechanisms by which obesity affects LBP, and inform novel approaches to managing LBP. The aim of this study was to examine the relationship between body composition and LBP intensity and disability.

Methods

A total of 5058 participants (44% men) of the Australian Diabetes, Obesity and Lifestyle Study were assessed for LBP intensity and disability using the Chronic Pain Grade Questionnaire (2013–2014). Body mass index (BMI) and waist circumference were directly obtained. Fat mass and percentage fat were estimated from bioelectrical impedance analysis at study inception (1999–2000).

Results

Eighty-two percent of participants reported LBP, of whom 27% also reported LBP disability. BMI, waist circumference, percent fat, and fat mass were each positively associated with LBP intensity and disability at 12 years after adjustment for potential confounders. LBP intensity and disability showed significant dose-responses to sex-specific quartiles of BMI, waist circumference, percent fat and fat mass. For example, the adjusted OR for LBP intensity in women increased with increasing fat mass quartiles [Q1: 1, Q2: 1.05 (95%CI 0.84–1.32); Q3: 1.25 (1.00–1.57); and Q4: 1.78 (1.42–2.24); p < 0.001].

Conclusions

Fat mass and distribution are associated with LBP intensity and disability, suggesting systemic metabolic factors associated with adiposity play a major role in the pathogenesis of LBP. Clarifying the mechanisms will facilitate developing novel preventive and therapeutic approaches for LBP.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1242-z) contains supplementary material, which is available to authorized users.

Characterization of risk factors for adjuvant radiotherapy-associated pain in a tri-racial/ethnic breast cancer population

Pain related to cancer or treatment is a critical quality of life issue for breast cancer survivors. In a prospective study of 375 patients with breast cancer (enrolled during 2008-2014), we characterized the risk factors for adjuvant radiotherapy (RT)-associated pain. Pain score was assessed at pre-RT and post-RT as the mean of 4 pain severity items (ie, pain at its worst, least, average, and now) from the Brief Pain Inventory with 11-point numeric rating scale (0-10). Pain scores of 4 to 10 were considered clinically relevant pain. The study consists of 58 non-Hispanic whites (15%), 78 black or African Americans (AA; 21%), and 239 Hispanic whites (HW; 64%). Overall, the prevalence of pre-RT, post-RT, and RT-associated clinically relevant pain was 16%, 31% and 20%, respectively. In univariate analysis, AA and HW had significantly higher pre-RT and post-RT pain than non-Hispanic whites. In multivariable logistic regression analysis, pre-RT pain was significantly associated with HW and obesity; post-RT pain was significantly associated with AA, HW, younger age, ≥2 comorbid conditions, above-median hotspot volume receiving >105% prescribed dose, and pre-RT pain score ≥4. Radiotherapy-associated pain was significantly associated with AA (odds ratio [OR] = 3.27; 95% confidence interval [CI] = 1.09-9.82), younger age (OR = 2.44, 95% CI = 1.24-4.79), and 2 or ≥3 comorbid conditions (OR = 3.06, 95% CI = 1.32-7.08; OR = 4.61, 95% CI = 1.49-14.25, respectively). These risk factors may help to guide RT decision-making process, such as hypofractionated RT schedule. Furthermore, effective pain management strategies are needed to improve quality of life in patients with breast cancer with clinically relevant pain.

Pain Intensity and Pain Interference in Older Adults: Role of Gender, Obesity and High-Sensitivity C-Reactive Protein

BACKGROUND

Among older adults, pain intensity and pain interference are more common in women than men and associated with obesity and inflammatory markers.

OBJECTIVE

We examined whether the obesity and pain relationship is mediated by the high-sensitivity C-reactive protein (hsCRP), a nonspecific marker of systemic inflammation, and whether this relationship differs by sex.

METHODS

Items from Medical Outcomes Study Short Form-36 were used to measure pain intensity and pain interference in daily life. Ordinal logistic regression was used to assess the cross-sectional association among body mass index (BMI), hsCRP levels, pain intensity and pain interference using gender-stratified models adjusted for demographic variables.

RESULTS

Participants included 667 community-residing adults over the age of 70 years, free of dementia, enrolled in the Einstein Aging Study (EAS). In women (n = 410), pain intensity was associated with obesity [BMI ≥30 vs. normal, odds ratio (OR) = 2.29, 95% confidence interval (CI) 1.43-3.68] and higher hsCRP (OR = 1.28, 95% CI 1.08-1.51). In a model with obesity and hsCRP, both remained significant, but the association between hsCRP and pain intensity was somewhat attenuated. Obesity (OR = 3.04, 95% CI 1.81-5.11) and higher hsCRP levels (OR = 1.30, 95% CI 1.08-1.56) were also independently associated with greater pain interference in women. After adjustment for pain intensity and BMI, hsCRP was no longer associated with pain interference in women. Greater pain intensity and being overweight or obese continued to be significantly associated with pain interference in women. In men (n = 257), obesity and hsCRP were not associated with pain intensity or pain interference.

CONCLUSIONS

In women, the relationship between obesity and higher levels of pain intensity or interference may be accounted for by factors related to hsCRP.

Relative abdominal adiposity is associated with chronic low back pain: a preliminary explorative study

Background

Although previous research suggests a relationship between chronic low back pain (cLBP) and adiposity, this relationship is poorly understood. No research has explored the relationship between abdominal-specific subcutaneous and visceral adiposity with pain and disability in cLBP individuals. The aim of this study therefore was to examine the relationship of regional and total body adiposity to pain and disability in cLBP individuals.

Methods

A preliminary explorative study design of seventy (n = 70) adult men and women with cLBP was employed. Anthropometric and adiposity measures were collected, including body mass index, waist-to-hip ratio, total body adiposity and specific ultrasound-based abdominal adiposity measurements. Self-reported pain and disability were measured using a Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI) questionnaires respectively. Relationships between anthropometric and adiposity measures with pain and disability were assessed using correlation and regression analyses.

Results

Significant correlations between abdominal to lumbar adiposity ratio (A-L) variables and the waist-to-hip ratio with self-reported pain were observed. A-L variables were found to predict pain, with 9.1–30.5 % of the variance in pain across the three analysis models explained by these variables. No relationships between anthropometric or adiposity variables to self-reported disability were identified.

Conclusions

The findings of this study indicated that regional distribution of adiposity via the A-L is associated with cLBP, providing a rationale for future research on adiposity and cLBP.

Obesity and chronic pain: systematic review of prevalence and implications for pain practice

The combination of obesity and pain may worsen a patient's functional status and quality of life more than each condition in isolation. We systematically searched PubMed/MEDLINE and the Cochrane databases for all reports published on obesity and pain. The prevalence of combined obesity and pain was substantial. Good evidence shows that weight reduction can alleviate pain and diminish pain-related functional impairment. However, inadequate pain control can be a barrier to effective lifestyle modification and rehabilitation. This article examines specific pain management approaches for obese patients and reviews novel interventional techniques for treatment of obesity. The infrastructure for simultaneous treatment of obesity and pain already exists in pain medicine (eg, patient education, behavioral medicine approaches, physical rehabilitation, medications, and interventional treatment). Screening for obesity, pain-related disability, and behavioral disorders as well as monitoring of functional performance should become routine in pain medicine practices. Such an approach requires additional physician and staff training. Further research should focus on better understanding the interplay between these 2 very common conditions and the development of effective treatment strategies.

The association between chronic pain and obesity

Obesity and pain present serious public health concerns in our society. Evidence strongly suggests that comorbid obesity is common in chronic pain conditions, and pain complaints are common in obese individuals. In this paper, we review the association between obesity and pain in the general population as well as chronic pain patients. We also review the relationship between obesity and pain response to noxious stimulation in animals and humans. Based upon the existing research, we present several potential mechanisms that may link the two phenomena, including mechanical/structural factors, chemical mediators, depression, sleep, and lifestyle. We discuss the clinical implications of obesity and pain, focusing on the effect of weight loss, both surgical and noninvasive, on pain. The literature suggests that the two conditions are significant comorbidities, adversely impacting each other. The nature of the relationship however is not likely to be direct, but many interacting factors appear to contribute. Weight loss for obese pain patients appears to be an important aspect of overall pain rehabilitation, although more efforts are needed to determine strategies to maintain long-term benefit.

Does Obesity Affect Outcomes After Decompressive Surgery for Lumbar Spinal Stenosis? A Multicenter, Observational, Registry-Based Study

OBJECTIVE

To evaluate the association between obesity and outcomes 1 year after laminectomy or microdecompression for lumbar spinal stenosis (LSS).

METHODS

The primary outcome measure was the Oswestry Disability Index (ODI). Obesity was defined as body mass index (BMI) ≥ 30. Prospective data were retrieved from the Norwegian Registry for Spine Surgery.

RESULTS

For all patients (n = 1473) the mean improvement in ODI at 1 year was 16.7 points (95% CI 15.7-17.7, P < 0.001). The improvement in ODI was 17.5 points in nonobese and 14.3 points in obese patients (P = 0 .007). Obese patients were less likely to achieve a minimal clinically important difference in ODI (defined as ≥ 8 points improvement) than nonobese patients (62.2 vs. 70.3%, P = 0.013). Obesity was identified as a negative predictor for ODI improvement in a multiple regression analysis (P < 0.001). Nonobese patients experienced more improvement in both back pain (0.7 points, P = 0.002) and leg pain (0.8 points, P = 0.001) measured by numeric rating scales. Duration of surgery was shorter for nonobese patients for both single- (79 vs. 89 minutes, P = 0.001) and 2-level (102 vs. 114 minutes, P = 0.004) surgery. There was no difference in complication rates (10.4% vs. 10.8%, P = 0.84). There was no difference in length of hospital stays for single- (2.7 vs. 3.0 days, P = 0.229) or 2-level (3.5 vs. 3.6 days, P = 0.704) surgery.

CONCLUSIONS

Both nonobese and obese patients report considerable clinical improvement 1 year after surgery for LSS, but improvement was less in obese patients. Obese patients were less likely to achieve a minimal clinically important difference.

Markers of inflammation and fibrinolysis in relation to outcome after surgery for lumbar disc herniation. A prospective study on 177 patients

PURPOSE

The role of inflammation and fibrinolysis for the development of back pain and sciatica has been discussed. The aim of this study was to assess the relationship between markers of inflammation and fibrinolysis, to predict the outcome after surgery for lumbar disc herniation.

METHODS

177 patients were recruited. High sensitive C-reactive protein (hsCRP), plasminogen activator inhibitor 1 (PAI-1), fibrinogen, and D-dimer were analyzed preoperatively. Visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol 5 Dimensions (EQ-5D) were assessed preoperatively and at 6 weeks, 6-, 12-, and 24- months postoperatively. Dichotomization was made at the median for the laboratory analyses, and between the worst quartile and the other three quartiles for the outcome variables. Logistic regression was used to determine the odds ratios (OR) and 95 % confidence intervals (CI).

RESULTS

The associations between PAI-1 and outcome seemed to be most prominent at the 6 and 12-month follow-up. When being in the upper half of PAI-1, the OR for being in the worst quartile of VAS back pain 12 months postoperatively was 3.33 (1.56-7.10). The corresponding OR for VAS leg pain was 2.46 (1.18-5.10), for ODI 2.83 (1.35-5.94) and for EQ-5D 2.73 (1.30-5.75). The OR for hsCRP was 2.10 (1.03-4.29) for being in the worst quartile of VAS back pain. Fibrinogen or D-dimer was not associated with any outcome variable.

CONCLUSIONS

High PAI-1, a marker of fibrinolysis, was fairly consistently associated with poor outcome, while hsCRP, fibrinogen, and D-dimer were not.