The journal of pain : official journal of the American Pain Society
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A cross-sectional epidemiologic survey was performed to determine the prevalence of chronic pain (CP) and to identify associated factors in a random sample of persons 15 years or older from a segment of the population of São Paulo City, Brazil. A total of 1,108 eligible participants were randomly selected, and face-to-face interviews were performed with 826 individuals (74.5%) between December 2011 and February 2012. Chronic Pain Grade, Hospital Anxiety and Depression Scale, and EuroQol-5D were used to verify pain characteristics and the associated signs of psychological distress. A prevalence of 42% (95% confidence interval, 38.6-45.4) was observed for CP, and the participants with CP had an average pain intensity of 5.9 (standard deviation = 1.9) and a pain-related disability of 4.1 (standard deviation = 3.2) on a 0 to 10 scale. Persistent pain was present in 68.6% of those with CP, and 32.8% of the population sample had high-intensity or high-interference pain (Chronic Pain Grade II, III, and IV). Quality of life was significantly worse among the CP individuals. The following factors were independently associated with CP: female gender, age 30 years or older, ≤ 4 years of education, symptoms consistent with anxiety, and intense physical strain. Indicators of pain severity increased with pain grades. ⋯ CP is highly prevalent in the city of São Paulo and has a considerable impact on health-related quality of life. Demographic, socioeconomic, and psychological factors are independently associated with this condition.
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Neuropathic pain is a debilitating condition caused by a lesion or disease of the somatosensory nervous system. Statins inhibit the rate-limiting step in cholesterol biosynthesis by blocking 3-hydroxy-3-methyl glutaryl coenzyme A reductase. Apart from the cholesterol-reducing actions of statins, recent studies have shown their pleiotropic actions; accordingly, their usefulness in attenuating different disease states has been described in preclinical studies. Studies in animals have also suggested their beneficial effects in attenuating neuropathic pain in various animal models of neuropathy. In these studies, their usefulness has been ascribed to cholesterol-independent actions, including anti-inflammatory, antioxidant, and neuromodulatory effects. On the contrary, clinical evidence suggests that statin administration in patients is associated with development of neuropathy, suggesting the dichotomous role of statins in neuropathic pain. The present review discusses the pain-attenuating as well as pain-inducing role of statins in preclinical and clinical studies, respectively. Furthermore, the review provides mechanistic insight to explain the paradoxical nature of this class of drugs in neuropathy in preclinical and clinical studies. ⋯ The article reviews the pain-inducing role of statins in clinical studies and its neuropathic pain-attenuating role in preclinical studies with possible mechanisms. Understanding key differences in mechanisms may help to attenuate pain induction in the clinical setting and may possibly project statins as neuropathic pain-attenuating agents.
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Whether patients receive guideline-concordant opioid therapy (OT) is largely unknown and may vary based on provider and patient characteristics. We assessed the extent to which human immunodeficiency virus (HIV)-infected and uninfected patients initiating long-term (≥ 90 days) OT received care concordant with American Pain Society/American Academy of Pain Medicine and Department of Veterans Affairs/Department of Defense guidelines by measuring receipt of 17 indicators during the first 6 months of OT. Of 20,753 patients, HIV-infected patients (n = 6,604) were more likely than uninfected patients to receive a primary care provider visit within 1 month (52.0% vs 30.9%) and 6 months (90.7% vs 73.7%) and urine drug tests within 1 month (14.8% vs 11.5%) and 6 months (19.5% vs 15.4%; all P < .001). HIV-infected patients were also more likely to receive OT concurrent with sedatives (24.6% vs 19.6%) and a current substance use disorder (21.6% vs 17.2%). Among both patient groups, only modest changes in guideline concordance were observed over time: urine drug tests and OT concurrent with current substance use disorders increased, whereas sedative coprescriptions decreased (all Ps for trend < .001). Over a 10-year period, on average, patients received no more than 40% of recommended care. OT guideline-concordant care is rare in primary care, varies by patient/provider characteristics, and has undergone few changes over time. ⋯ The promulgation of OT clinical guidelines has not resulted in substantive changes over time in OT management, which falls well short of the standard recommended by leading medical societies. Strategies are needed to increase the provision of OT guideline-concordant care for all patients.
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There is emerging evidence that chronic musculoskeletal pain is associated with anatomic and functional abnormalities in gray matter. However, little research has investigated the relationship between chronic musculoskeletal pain and white matter. In this study, we used whole-brain tract-based spatial statistics and region-of-interest analyses of diffusion tensor imaging data to demonstrate that patients with chronic musculoskeletal pain exhibit several abnormal metrics of white matter integrity compared with healthy controls. Chronic musculoskeletal pain was associated with lower fractional anisotropy in the splenium of the corpus callosum and the left cingulum adjacent to the hippocampus. Patients also had higher radial diffusivity in the splenium, right anterior and posterior limbs of the internal capsule, external capsule, superior longitudinal fasciculus, and cerebral peduncle. Patterns of axial diffusivity (AD) varied: patients exhibited lower AD in the left cingulum adjacent to the hippocampus and higher AD in the anterior limbs of the internal capsule and in the right cerebral peduncle. Several correlations between diffusion metrics and clinical variables were also significant at a P < .01 level: fractional anisotropy in the left uncinate fasciculus correlated positively with total pain experience and typical levels of pain severity. AD in the left anterior limb of the internal capsule and left uncinate fasciculus was correlated with total pain experience and typical pain level. Positive correlations were also found between AD in the right uncinate and both total pain experience and pain catastrophizing. These results demonstrate that white matter abnormalities play a role in chronic musculoskeletal pain as a cause, a predisposing factor, a consequence, or a compensatory adaptation. ⋯ Patients with chronic musculoskeletal pain exhibit altered metrics of diffusion in the brain's white matter compared with healthy volunteers, and some of these differences are directly related to symptom severity.