{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,9]],"date-time":"2025-12-09T12:12:18Z","timestamp":1765282338227,"version":"3.46.0"},"reference-count":48,"publisher":"Walter de Gruyter GmbH","issue":"1","license":[{"start":{"date-parts":[[2025,1,1]],"date-time":"2025-01-01T00:00:00Z","timestamp":1735689600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,11,18]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>\n                      The endocannabinoid system is a neuromodulatory system linked to pain, distress, and physical activity. The endocannabinoids (eCBs) arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol are known to activate the cannabinoid receptors. The eCB system has been reported to be acutely affected by physical activity. Altered connectivity related to pain intensity in patients with fibromyalgia (FM) has been reported. However, how the peripheral eCBs, including eCB-like\n                      <jats:italic>N<\/jats:italic>\n                      -acylethanolamines (NAEs) concentrations, associate with pain-related regions of the brain and physical activity in FM, is not known. This study aimed to investigate eCBs and eCB-like NAEs in plasma and the association with functional connectivity in brain regions relevant for pain and with physical fitness.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>The plasma concentrations of eCBs and eCB-like NAEs were measured in 31 women with FM and 29 healthy controls (HC). Functional magnetic resonance imaging, measurement of physical fitness and questionnaire regarding pain and depression\/anxiety were included.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Significantly higher concentrations of AEA were found in FM compared to HC. The AEA level correlated positively with pain intensity and was inversely associated with physical fitness, which in turn were inversely correlated with pain intensity and psychological distress in FM. Periaqueductal gray (PAG)-thalamus connectivity was not associated with circulating eCB and eCB-like NAEs. Stronger PAG-thalamus connectivity was related to a higher level of physical activity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>These results confirm that impaired physical fitness is an important aspect of FM, which can be reflected in the increased eCB levels and in PAG-thalamus connectivity. Further studies are necessary to establish a causal relationship between physical fitness, eCBs, eCB-like NAEs, and brain connectivity.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1515\/sjpain-2025-0023","type":"journal-article","created":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T08:59:55Z","timestamp":1763456395000},"source":"Crossref","is-referenced-by-count":0,"title":["Investigation of endocannabinoids in plasma and their correlation with physical fitness and resting state functional connectivity of the periaqueductal grey in women with fibromyalgia: An exploratory secondary study"],"prefix":"10.1515","volume":"25","author":[{"given":"Bijar","family":"Ghafouri","sequence":"first","affiliation":[{"name":"Pain and Rehabilitation Centre, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 85 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Niclas","family":"Stensson","sequence":"additional","affiliation":[{"name":"Pain and Rehabilitation Centre, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 85 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rozalyn","family":"Simon","sequence":"additional","affiliation":[{"name":"Division of Diagnostics and Specialist Medicine, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , Link\u00f6ping , Sweden"},{"name":"Center for Medical Image Science and Visualization (CMIV), Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leah M.","family":"Mayo","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Cumming School of Medicine, Hotchkiss Brain Institute, and The Mathison Centre for Mental Health Research and Education, University of Calgary , Calgary , Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eva","family":"Lund","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mikael F.","family":"Forsgren","sequence":"additional","affiliation":[{"name":"Center for Medical Image Science and Visualization (CMIV), Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"},{"name":"Radiation Physics, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"},{"name":"AMRA Medical AB, and Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olof Dahlqvist","family":"Leinhard","sequence":"additional","affiliation":[{"name":"Center for Medical Image Science and Visualization (CMIV), Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"},{"name":"Radiation Physics, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"},{"name":"AMRA Medical AB, and Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Lundberg","sequence":"additional","affiliation":[{"name":"Center for Medical Image Science and Visualization (CMIV), Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"},{"name":"Radiation Physics, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Helene","family":"van Ettinger-Veenstra","sequence":"additional","affiliation":[{"name":"Pain and Rehabilitation Centre, Department of Health, Medicine and Caring Sciences, Link\u00f6ping University , SE 581 85 , Link\u00f6ping , Sweden"},{"name":"Center for Medical Image Science and Visualization (CMIV), Link\u00f6ping University , SE 581 83 , Link\u00f6ping , Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2025,11,18]]},"reference":[{"key":"2025120909552355289_j_sjpain-2025-0023_ref_001","doi-asserted-by":"crossref","unstructured":"Alciati A, Nucera V, Masala IF, Giallanza M, La Corte L, Giorgi V, et al. 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