Pain
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The EQ-5D and Short Form (SF)12 are widely used generic health-related quality of life (HRQoL) questionnaires. They can be used to derive health utility index scores, on a scale where 0 is equivalent to death and 1 represents full health, with scores less than zero representing states "worse than death." We compared EQ-5D or SF-6D health utility index scores in patients with no chronic pain, and chronic pain with and without neuropathic characteristics (NC), and to explore their discriminant ability for pain severity. Self-reported health and chronic pain status was collected as part of a UK general population survey (n=4451). ⋯ Health utilities derived from EQ-5D and SF-12/36 can discriminate between group differences for chronic pain with and without NC and greater pain severity. However, the instruments generate widely differing HRQoL scores for the same patient groups. The choice between using the EQ-5D or SF-6D matters greatly when estimating the burden of disease.
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Living in a lower socioeconomic status neighborhood has been shown to alter stress system function and is associated with a number of adverse health outcomes, but its influence on musculoskeletal pain (MSP) outcomes after traumatic stress exposures such as motor vehicle collision (MVC) has not been assessed. We performed a multicenter, prospective study that enrolled 948 European-American individuals within 24 hours of MVC who were discharged home after emergency department evaluation. Follow-up evaluations were completed via telephone or Internet survey 6 weeks, 6 months, and 1 year after MVC on 91%, 89%, and 91% of participants, respectively. ⋯ After adjustment for individual-level factors, living in more disadvantaged neighborhoods was associated with increased MSP (P=0.0009) and increased pain interference with daily function (P<0.0001). The relationship between neighborhood disadvantage and MSP was moderated by a common single nucleotide polymorphism, rs2817038, 5' of the gene encoding FKBP5, a functional regulator of glucocorticoid receptor sensitivity (interaction P-value=0.0015). These data support the hypothesis that low neighborhood socioeconomic status increases the likelihood of worse MSP outcomes after traumatic stress exposures such as MVC, and that this influence is mediated in part via its influence on stress system function.
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μ-Opioids remain vastly important for the treatment of pain, and would represent ideal analgesics if their analgesic effects could be separated from their many side effects. A recently synthesized compound, iodobenzoylnaltrexamide (IBNtxA), acting at 6-transmembrane (6-TM) splice variants of the μ-opioid receptor gene, was shown to have potent analgesic actions against acute, thermal pain accompanied by a vastly improved side-effect profile compared to 7-TM-acting drugs such as morphine. Whether such analgesia can be seen in longer-lasting and nonthermal algesiometric assays is not known. ⋯ We further demonstrate the dependence of such analgesia on 6-TM μ-opioid receptor variants using isobolographic analysis and the testing of Oprm1 (the μ-opioid receptor gene) exon 11 null mutant mice. Finally, the effect of nerve damage (spared nerve injury) and inflammatory injury (complete Freund's adjuvant) on expression of μ-opioid receptor variant genes in pain-relevant central nervous system loci was examined, revealing a downregulation of the mMOR-1D splice variant in the dorsal root ganglion after spared nerve injury. These findings are supportive of the potential value of 6-TM-acting drugs as novel analgesics.