Pain
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Chronic ischemic pain in peripheral arterial disease (PAD) is a leading cause of pain in the lower extremities. A neuropathic component of chronic ischemic pain has been shown independent of coexisting diabetes. We aimed to identify a morphological correlate potentially associated with pain and sensory deficits in PAD. ⋯ Mean S100 beta levels were in the normal range but were higher in advanced disease. Patients with chronic ischemic pain had a reduced IENFD associated with impaired sensory functions. These findings support the concept of a neuropathic component in ischemic pain.
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Toll-like receptors (TLR) are known to play a role in chronic pain, from animal models and limited research in humans, but their role in interstitial cystitis/bladder pain syndrome (IC/BPS) is unknown. Similarly, alterations of the hypothalamic-pituitary-adrenal axis have been reported in some pain conditions. Our objectives were to identify inflammatory processes that might distinguish individuals with IC/BPS from healthy controls (HC) and to examine their associations with IC/BPS symptoms. ⋯ Genitourinary pain severity (P=.008), frequency (P=.001), and pain with intercourse (P=.002) were strongly associated with TLR-4 inflammatory response. TLR-4 appears to play a central role in painful symptoms of IC/BPS patients, which may be linked to poor endogenous inflammatory control. These findings may help to identify new mechanisms in IC/BPS and lead to new therapeutic approaches.
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The evidence on the patterns of nonsteroidal anti-inflammatory drug (NSAID) use according to pain prevalence and clinical guidelines in older people is sparse. This cross-sectional study examined the patterns of NSAID use according to pain prevalence and concordance with clinical guideline recommendations for safe NSAID use in older people, in relation to duration of use, patterns of use, concomitant use of proton pump inhibitors (PPIs), and prevalence of specific drug interactions. Community-dwelling men (n=1696) age ≥ 70 years living in Sydney were studied. 8.2% (n=139) of participants reported regular NSAID use compared with 2.9% (n=50) reporting as-needed use. ⋯ In relation to pain prevalence, regular NSAID users were significantly more likely to report chronic pain (P<.0001), recent pain (P=.0001), and chronic intrusive pain (P<.0001) compared with nonregular users. The findings of this study indicate that NSAID prescribing practices do not align with clinical guidelines for safe use in older people. This difference between the guideline recommendations and what is happening in the real world should be explored further.
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Candidate gene studies have revealed limited genetic bases for opioid analgesic response variability. Genome-wide association studies facilitate impartial queries of common genetic variants, allowing identification of novel genetic contributions to drug effect. Illumina (Illumina Inc, San Diego, CA, USA) single nucleotide polymorphism (SNP) arrays were used to investigate SNP associations with total morphine requirement as a quantitative trait locus and with postoperative pain in a retrospective population of opioid-naïve children ages 4-18years who had undergone day surgery tonsillectomy and adenoidectomy. ⋯ No association with morphine dose was detected in African Americans (AA) (n=241). Postoperative pain scores ≥ 7/10 were associated with rs795484 (G>A) in the EC cohort (odds ratio 2.35, 95% CI 1.56-3.52, P<0.00005) and this association replicated in AA children (odds ratio 1.76, 95% CI 1.14-2.71, P<0.01). Variants in TAOK3 encoding the serine/threonine-protein kinase, TAO3, are associated with increased morphine requirement in children of EC ancestry and with increased acute postoperative pain in both EC and AA subjects.