{ "abstract": "Rationale & objective\n\n3-epi-25(OH)D₃, an epimeric form of 25(OH)D₃ generated by C-3 epimerization, declines with advancing chronic kidney disease (CKD), yet its role in vascular health and related outcomes remains largely unknown. We aimed to determine whether circulating 3-epi-25(OH)D₃ levels are associated with arterial stiffness and longitudinal cardiovascular (CV) outcomes in advanced CKD (stages 5 and 5D).Study design\n\nA prospective observational study.Setting & participants\n\nA total of 270 patients with advanced CKD using the Cambridge Coventry Vascular cohort.Exposure s or predictor s\n\nBaseline 3-epi-25(OH)D₃ measured by liquid chromatography-tandem mass spectrometry.Outcome s\n\nArterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx75). Longitudinal outcomes included a composite of major CV events and all-cause mortality.Analytical approach\n\nBaseline 3-epi-25(OH)D₃ was categorized into quartiles. Associations were assessed using multivariable regression adjusted for age, race, and dialysis status. Kaplan-Meier and Cox models assessed longitudinal outcomes.Results\n\nAmong 270 participants, quartiles were Q1 < 0.30 ng/mL (n = 64), Q2: 0.30-0.456 ng/mL (n = 71), Q3: 0.457-0.729 ng/mL (n = 68), and Q4 ≥ 0.73 ng/mL (n = 67). Strata were similar in age (44.9 years), sex, and BMI (all P > 0.05). Race differed by quartile (P < 0.001); 87.4% were White. 24.8% were pre-dialytic, 61.1% treated with hemodialysis, and 14.1% treated with peritoneal dialysis. Arterial stiffness was similar across quartiles (AIx75 ∼20-21%, P = 0.99; PWV: 7.8-8.0 m/s, P = 0.94). 3-epi-25(OH)D₃ showed no association with AIx75 or PWV before or after adjustment using multiple regression modeling. Over 9.3 years, 115 composite events occurred (97 CV events, 18 deaths). Kaplan-Meier analysis did not discriminate risk across 3-epi-25(OH)D₃ quartiles for the composite outcome (log-rank P = 0.23), and adjusted Cox models showed no association.Limitations\n\nObservational design with possible residual confounding.Conclusion\n\nIn advanced CKD, 3-epi-25(OH)D₃ showed no independent association with arterial stiffness or CV events and mortality. Further studies are needed to determine the role of epimeric vitamin D in patients with CKD.", "abstract_shown": true, "affiliations": [ "Division of Nephrology & Hypertension, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN.", "Department of Geriatric and Gerontology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.", "Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.", "Department of Biostatistics and Health Data Science, Indiana University School of Medicine, Indianapolis, IN.", "Department of Biostatistics and Health Data Science and Richard M. Fairbanks School of Public Health, Indiana University School of Medicine, Indianapolis, IN.", "Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.", "Department of Biomedical and Molecular Sciences and Medicine, Queen's University, Kingston, Ontario, Canada.", "Department of Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.", "Department of Nephrology and Department of Acute Medicine, North Cumbria University Hospital NHS Trust, Carlisle, UK.", "Cambridge Clinical Trials Unit and School of Clinical Medicine, University of Cambridge, Cambridge, UK." ], "article_type": "research article", "arxiv": null, "author_total": 13, "authors": [ { "affs": [ 0 ], "name": "Monique O Campos" }, { "affs": [ 0, 1, 2 ], "name": "Chien-Yao Sun" }, { "affs": [ 3 ], "name": "Heather N Burney" }, { "affs": [ 4 ], "name": "Yang Li" }, { "affs": [ 0 ], "name": "Gayatri Narayanan" }, { "affs": [ 0 ], "name": "Olivia Carlton" }, { "affs": [ 5 ], "name": "Tzong-Shi Lu" }, { "affs": [ 6 ], "name": "Glenville Jones" }, { "affs": [ 6 ], "name": "Martin Kaufmann" }, { "affs": [ 7 ], "name": "Stephen M S Ting" }, { "affs": [ 8 ], "name": "Daniel Zehnder" }, { "affs": [ 9 ], "name": "Thomas Hiemstra" }, { "affs": [ 0 ], "name": "Kenneth Lim" } ], "bibtex": "https://research.draconitic.com/paper/9jatdqpwftede.bib", "cited_by": 0, "doi": "10.1016/j.xkme.2026.101519", "fulltext_url": "https://europepmc.org/articles/PMC13677220", "id": "9jatdqpwftede", "issns": [ "2590-0595" ], "landing_url": "https://europepmc.org/article/MED/42894851", "language": "eng", "licence": "CC-BY-NC-ND", "licence_label": "CC BY-NC-ND", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/", "metadata_licence": null, "native_subjects": [ [ "openalex", "2734|Vitamin D Research Studies" ] ], "openalex": "W7212036330", "pdf_url": "https://europepmc.org/articles/PMC13677220?pdf=render", "pmcid": "PMC13677220", "pmid": "42894851", "published": "2026-09-09", "publisher": null, "ris": "https://research.draconitic.com/paper/9jatdqpwftede.ris", "sources": [ { "first_seen": "2026-10-30T12:19:41Z", "native_id": "MED:42894851", "source": "europepmc", "url": "https://europepmc.org/article/MED/42894851" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2734|Vitamin D Research Studies", "subfield": "general" } ], "title": "Epimeric Vitamin D is Not Associated With Arterial Stiffness or Cardiovascular Outcomes in Patients With Advanced CKD.", "title_text": "Epimeric Vitamin D is Not Associated With Arterial Stiffness or Cardiovascular Outcomes in Patients With Advanced CKD.", "type": "peer-reviewed", "updated_at": "2026-10-30T12:19:41Z", "url": "https://research.draconitic.com/paper/9jatdqpwftede", "venue": "Kidney medicine", "versions": [] }