{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T18:07:41Z","timestamp":1781633261598,"version":"3.54.5"},"posted":{"date-parts":[[2026,1,30]]},"group-title":"Rheumatology","reference-count":43,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T00:00:00Z","timestamp":1769731200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,1,30]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by metabolic dysregulation, including altered lipid metabolism. While polyunsaturated fatty acids have been studied, the plasma levels, endogenous synthesis, and relevance of monounsaturated fatty acids (MUFAs) in RA remain unclear. This study examined plasma MUFA levels in RA and their associations with disease activity, adiposity, and intake.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>In this cross-sectional study, 59 individuals with rheumatoid arthritis (RA) and 33 non-RA controls frequency-matched on age, sex, and BMI were recruited between 2017 and 2022. Clinical assessments included disease activity (DAS28), body composition, and metabolic parameters. Dietary intake was assessed using a 4-day food journal, and plasma fatty acids were quantified by gas chromatography in 82 participants with available samples. The stearoyl-CoA desaturase-1 (SCD-1) index was used as a proxy for endogenous MUFA synthesis. Associations between MUFAs and clinical variables were evaluated using univariate and multivariable regression (p&lt;0.05).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>RA participants had higher waist-to-hip ratio, fat mass, fasting triglycerides, and lower physical activity than controls. Plasma palmitoleic and oleic acids and the SCD-1 index were higher in RA, whereas linoleic and arachidonic acids were lower. Saturated and omega-3 fatty acids were similar. Higher oleic and gondoic acids were independently associated with greater disease activity; oleic acid was linked to central adiposity, and palmitoleic acid was higher in women, suggesting sex\u2013 and adiposity-specific regulation.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Higher plasma MUFAs in RA are associated with disease activity, adiposity, and sex, highlighting altered MUFA metabolism as a feature of RA and a potential target for metabolic intervention.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Key Messages<\/jats:title>\n                  <jats:sec>\n                    <jats:title>What is already known on this topic<\/jats:title>\n                    <jats:p>Rheumatoid arthritis (RA) involves systemic inflammation and altered lipid metabolism. While polyunsaturated fatty acids have been studied extensively, the plasma levels, endogenous synthesis, and clinical relevance of monounsaturated fatty acids (MUFAs) in RA remain unclear.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>What this study adds<\/jats:title>\n                    <jats:p>Patients with RA have higher plasma MUFAs, including oleic and palmitoleic acids, and an elevated SCD-1 index, a marker of endogenous MUFA synthesis. Higher MUFAs are associated with disease activity, central adiposity, and sex-specific patterns, independent of dietary intake.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>How this study might affect research, practice or policy<\/jats:title>\n                    <jats:p>Plasma MUFAs could serve as potential biomarkers of RA disease activity and metabolic dysregulation. These findings suggest that altered MUFA metabolism contributes to inflammatory pathways, highlighting a potential target for future research, nutritional interventions, or therapeutic strategies.<\/jats:p>\n                  <\/jats:sec>\n                <\/jats:sec>","DOI":"10.64898\/2026.01.27.26344951","type":"posted-content","created":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T22:25:23Z","timestamp":1769811923000},"source":"Crossref","is-referenced-by-count":1,"title":["Elevated Plasma Monounsaturated Fatty Acids and Their Associations with Disease Activity, Adiposity, and Sex in Patients with Rheumatoid Arthritis: A Cross-Sectional Study"],"prefix":"10.64898","author":[{"given":"Shalini N.","family":"Swamy","sequence":"first","affiliation":[{"name":"Department of Medicine, Section of Rheumatology, Immunology and Allergy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martha A.","family":"Belury","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, The Ohio State University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rachel M.","family":"Cole","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, The Ohio State University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristen","family":"Heitman","sequence":"additional","affiliation":[{"name":"Division of Health Sciences, The Ohio State University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven","family":"Pan","sequence":"additional","affiliation":[{"name":"Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhibo","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Biochemistry & Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aizhan","family":"Karabukayeva","sequence":"additional","affiliation":[{"name":"Department of Health Administration & Policy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Mao-Draayer","sequence":"additional","affiliation":[{"name":"Multiple Sclerosis Center of Excellence Oklahoma Medical Research Foundation, Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2695-4852","authenticated-orcid":false,"given":"Beatriz Y.","family":"Hanaoka","sequence":"additional","affiliation":[{"name":"Department of Medicine, Section of Rheumatology, Immunology and Allergy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026020212300547000_2026.01.27.26344951v1.1","doi-asserted-by":"publisher","DOI":"10.1002\/art.27629"},{"key":"2026020212300547000_2026.01.27.26344951v1.2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMra1004965"},{"key":"2026020212300547000_2026.01.27.26344951v1.3","doi-asserted-by":"publisher","DOI":"10.1042\/BST20160474"},{"key":"2026020212300547000_2026.01.27.26344951v1.4","doi-asserted-by":"publisher","DOI":"10.1038\/sj.ejcn.1601478"},{"issue":"1","key":"2026020212300547000_2026.01.27.26344951v1.5","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1186\/s13075-022-02781-2","article-title":"Impact of type and dose of oral polyunsaturated fatty acid supplementation on disease activity in inflammatory rheumatic diseases: a systematic literature review and meta-analysis","volume":"24","year":"2022","journal-title":"Arthritis Res Ther"},{"issue":"2","key":"2026020212300547000_2026.01.27.26344951v1.6","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1002\/acr.23245","article-title":"Dietary Intake of Polyunsaturated Fatty Acids and Pain in Spite of Inflammatory Control Among Methotrexate-Treated Early Rheumatoid Arthritis Patients","volume":"70","year":"2018","journal-title":"Arthritis Care Res (Hoboken"},{"key":"2026020212300547000_2026.01.27.26344951v1.7","doi-asserted-by":"crossref","unstructured":"Veselinovic M , Vasiljevic D , Vucic V , Arsic A , Petrovic S , Tomic-Lucic A , et al. 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