{
  "abstract": "Calculated total antioxidant capacity (cTAC), a weighted sum of albumin, urate and bilirubin, is often interpreted as a single antioxidant dimension. We asked whether its constituents share the same association with leukocyte count, a routine but nonspecific marker of the inflammatory, oxidant-generating cell compartment, and examined 25-hydroxyvitamin D [25(OH)D]. In this retrospective cross-sectional study of routine records from a tertiary university hospital laboratory (2014–2023; 20,525 patient-years, 14,152 adults), cTAC was calculated with Trolox-equivalent coefficients (0.63·albumin + 1.02·urate + 1.50·bilirubin). Patient-clustered models of log leukocyte count, leukopenia (<4 × 109/L) and leukocytosis (≥10 × 109/L) were adjusted for age, sex, season and era, and additionally for estimated glomerular filtration rate and alanine aminotransferase. Urate accounted for 90% of the variance of cTAC. cTAC showed a U-shaped association with leukocytosis, whereas its components diverged. Per standard deviation, urate was associated with more leukocytes (+4.2%, 95% CI 3.2–5.2; leukocytosis odds ratio [OR] 1.23, 1.14–1.32) and calculated unconjugated bilirubin with fewer (−4.3%, −5.7 to −2.9; OR 0.71, 0.63–0.82). Both associations were similar after multiple imputation of missing covariates. Platelet adjustment attenuated the bilirubin estimate to −1.4%, whereas haemoglobin adjustment did not; with platelet counts of 150–400 × 109/L and no anaemia, it was −3.8% (−5.0 to −2.7). 25(OH)D was weakly inversely associated (−1.2%, −1.8 to −0.6), without evidence of effect modification. In this cross-sectional setting, in which residual confounding is likely, a single calculated antioxidant capacity statistically conceals opposite-signed associations of its constituents with leukocyte count.",
  "abstract_shown": true,
  "affiliations": [
    "Clinical Institute of Clinical Chemistry and Biochemistry, University Medical Centre Ljubljana, Zaloška Cesta 2, 1000 Ljubljana, Slovenia",
    "Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000 Ljubljana, Slovenia",
    "Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška Ulica 8, 6000 Koper, Slovenia",
    "Department of Gastroenterology, University Medical Centre Ljubljana, Zaloška Cesta 2, 1000 Ljubljana, Slovenia",
    "Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Joško Osredkar",
      "orcid": "0000-0002-1839-2415"
    },
    {
      "affs": [
        2
      ],
      "name": "Uroš Godnov",
      "orcid": "0000-0003-4447-3435"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Aleš Jerin",
      "orcid": "0000-0002-6748-7082"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Darko Siuka"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9xdvg3eryhkvf.bib",
  "cited_by": 0,
  "doi": "10.3390/ijms27219483",
  "fulltext_url": null,
  "id": "9xdvg3eryhkvf",
  "issns": [
    "1422-0067"
  ],
  "landing_url": "https://www.mdpi.com/1422-0067/27/21/9483",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2704|Antioxidant Activity and Oxidative Stress"
    ]
  ],
  "openalex": "W7223855650",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/9xdvg3eryhkvf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:57Z",
      "native_id": "10.3390/ijms27219483",
      "source": "crossref",
      "url": "https://www.mdpi.com/1422-0067/27/21/9483"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2704|Antioxidant Activity and Oxidative Stress",
      "subfield": "general"
    }
  ],
  "title": "Calculated Serum Antioxidant Capacity Masks Opposite Associations of Urate and Unconjugated Bilirubin with Leukocyte Count: A Ten-Year Cross-Sectional Hospital Laboratory Study Including 25-Hydroxyvitamin D",
  "title_text": "Calculated Serum Antioxidant Capacity Masks Opposite Associations of Urate and Unconjugated Bilirubin with Leukocyte Count: A Ten-Year Cross-Sectional Hospital Laboratory Study Including 25-Hydroxyvitamin D",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:57Z",
  "url": "https://research.draconitic.com/paper/9xdvg3eryhkvf",
  "venue": "International Journal of Molecular Sciences",
  "versions": []
}