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Relationships Between Pain, Life Stress, Sociodemographics, and Cortisol: Contributions of Pain Intensity and Financial Satisfaction.

The relationship between psychosocial stress and chronic pain is bidirectional. An improved understanding regarding the relationships among chronic pain, life stress, and ethnicity/race will inform identification of factors contributing to health disparities in chronic pain and improve health outcomes. This study aims to assess relationships between measures of clinical pain, life stress, sociodemographics, and salivary cortisol levels.

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Phenotyping peripheral neuropathic pain in male and female adolescents: pain descriptors, somatosensory profiles, conditioned pain modulation, and child-parent reported disability.

Neuropathic pain (NeuP) can be difficult to diagnose and manage in children. Data regarding prevalence and sex-dependent differences are limited, and more detailed phenotyping is needed. This observational cohort study recruited adolescents (10-17 years) with NeuP or complex regional pain syndrome (CRPS). After pain history and NeuP questionnaires, quantitative sensory testing was performed. Individual z-score plots were calculated with body-region control measures and matched to mechanism-related sensory profiles (sensory loss, thermal hyperalgesia, and mechanical hyperalgesia). Conditioned pain modulation was assessed with pressure pain threshold and a contralateral cold conditioning stimulus, and meaningful conditioned pain modulation defined as twice the standard error of measurement. Patients and parents completed validated questionnaires for child quality of life (QoL), pain catastrophizing, and self-reported anxiety/depression. Males (n = 23) and females (n = 43) with NeuP (n = 52) or CRPS (n = 14) reported moderate-severe pain with neuropathic sensory descriptors. Mixed patterns of sensory gain/loss at pain sites were not sex-dependent. Thermal hyperalgesia was common in both NeuP and CRPS, whereas sensory loss occurred only with NeuP and in a smaller proportion than adult cohorts. Conditioned pain modulation was inhibitory in 54%, facilitatory in 14%, and nonresponders had variable cold conditioning sensitivity. Males and females reported marked impairment of QoL, increased emotional distress, and pain catastrophising. Child-parent QoL scores correlated, but catastrophizing scores were discordant when parents or adolescents reported higher anxiety/depression. NeuP in adolescents is associated with significant pain, physical impairment, and psychosocial impairment. Quantifying alterations in somatosensory profiles, descending modulation, child and parent psychological function will inform individualized therapy and stratification for future clinical trials.

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Associations of Sleep Disturbance, Atopy, and Other Health Measures with Chronic Overlapping Pain Conditions.

To quantify the contributions of atopic disorders, sleep disturbance, and other health conditions to five common pain conditions.

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Serum soluble urokinase plasminogen activator receptor in adolescents: interaction of chronic pain and obesity.

Obesity in adolescents is increasing in frequency and is associated with short-term and long-term negative consequences that include the exacerbation of co-occurring chronic pain.

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Evaluation of the chronic pain classification: study protocol for an ecological implementation field study in low-, middle-, and high-income countries.

The purpose of the present ecological implementation field study is to evaluate the new classification of chronic pain as implemented in the 11th revision of the () with regard to clinical utility and interrater reliability. To evaluate the classification in a variety of settings, the study will be implemented in different low-, middle-, and high-income countries.

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Resilience factors may buffer cellular aging in individuals with and without chronic knee pain.

Telomere length, a measure of cellular aging, is inversely associated with chronic pain severity. While psychological resilience factors (e.g., optimism, acceptance, positive affect, active coping) are associated with lower levels of clinical pain and greater physical functioning, it is unknown whether resilience may buffer against telomere shortening in individuals with chronic pain. Additionally, a broader conceptualization of resilience that includes social and biobehavioral factors may improve our understanding of the relationship between resilience, chronic pain, and health outcomes. In individuals with and without chronic knee pain, we investigated whether: 1) psychological resilience would be positively associated with telomere length, and if 2) a broader conceptualization of resilience including social and biobehavioral factors would strengthen the association. Seventy-nine adults, 45-85 years of age, with and without knee pain completed demographic, health, clinical pain, psychological, social, and biobehavioral questionnaires. Resilience levels were determining by summing the total number of measures indicating resilience based on published clinical ranges and norms. Blood samples were collected and telomere length determined. In regression analyses controlling for sex, race, age, and characteristic pain intensity, greater psychological resilience and psychosocial/biobehavioral resilience were associated with longer telomeres (p = .0295 and p = .0116, respectively). When compared, psychosocial/biobehavioral resilience was significantly more predictive of telomere length than the psychological resilience (p < .0001). Findings are promising and encourage further investigations to enhance understanding of the biological interface of psychosocial and biobehavioral resilience factors in individuals with musculoskeletal chronic pain conditions.

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Haploinsufficiency of the brain-derived neurotrophic factor gene is associated with reduced pain sensitivity.

Rare pain-insensitive individuals offer unique insights into how pain circuits function and have led to the development of new strategies for pain control. We investigated pain sensitivity in humans with WAGR (Wilms tumor, aniridia, genitourinary anomaly, and range of intellectual disabilities) syndrome, who have variably sized heterozygous deletion of the 11p13 region. The deletion region can be inclusive or exclusive of the brain-derived neurotrophic factor (BDNF) gene, a crucial trophic factor for nociceptive afferents. Nociceptive responses assessed by quantitative sensory testing demonstrated reduced pain sensitivity only in the WAGR subjects whose deletion boundaries included the BDNF gene. Corresponding behavioral assessments were made in heterozygous Bdnf knockout rats to examine the specific role of Bdnf. These analogous experiments revealed impairment of Aδ- and C-fiber-mediated heat nociception, determined by acute nociceptive thermal stimuli, and in aversive behaviors evoked when the rats were placed on a hot plate. Similar results were obtained for C-fiber-mediated cold responses and cold avoidance on a cold-plate device. Together, these results suggested a blunted responsiveness to aversive stimuli. Our parallel observations in humans and rats show that hemizygous deletion of the BDNF gene reduces pain sensitivity and establishes BDNF as a determinant of nociceptive sensitivity.

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Increased pain sensitivity but normal pain modulation in adolescents with migraine.

Inhibitory pain modulation has been reported to be deficient in adults across different types of chronic pain, including migraine. To determine if a similar phenomenon occurs in youth, we performed a quantitative sensory testing investigation in adolescents with migraine (N=19). These patients were compared to healthy adolescents with (Fam-His; N=20) or without (Healthy; N=29) a family history of migraine (e.g., first degree relative with migraine). Subjects were first familiarized with the stimuli and visual analog rating scales using graded noxious stimuli (0°C, 43-49°C range). These data were used to explore potential pain sensitivity differences between the groups. Pain inhibition was assessed by conditioned pain modulation (CPM), which used both suprathreshold heat pain (heat CPM) and pressure pain thresholds (pressure CPM) as the test stimuli before and during cold water immersion (8°C). In response to the graded heat stimuli Fam-His participants reported higher pain intensity ratings compared to migraine patients, who in turn, reported higher pain intensity ratings than the healthy controls [F=3.6, (df=2, 459), p=0.027]. For heat- and pressure- CPM, there was no significant group difference in the magnitude of CPM responses. Thus, adolescents with migraine and healthy adolescents have similar inhibitory pain modulation capability despite having marked differences in pain sensitivity. Although Fam-His participants are asymptomatic, they demonstrate alterations in pain processing which may serve as markers for prediction of migraine development.

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Differences in plasma lipoprotein profiles between patients with chronic peripheral neuropathic pain and healthy controls: an exploratory pilot study.

Little is still known about the underlying mechanisms that drive and maintain neuropathic pain (NeuP). Recently, lipids have been implicated as endogenous proalgesic ligands affecting onset and maintenance of pain; however, in the case of NeuP, the relationship is largely unexplored.

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Exploring the feasibility and acceptability of a sleep wearable headband among a community sample of chronic pain individuals: An at-home observational study.

Chronic pain conditions affect up to one third of the adult population in the United Kingdom. Sleep problems are prevalent and negatively impact quality of life. Lack of standardised tools for routine screening and assessment of sleep changes have been a barrier for sleep management. Novel sleep wearables offer an exciting and accessible way to measure sleep but have not been tested outside of the consumer-led landscape and are not commonly used in research and clinical settings.

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