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    "key": "pyrkov-2021",
    "id": "TAP-RDN-0052",
    "locale": "en",
    "path": "/research/pyrkov-2021/",
    "title": "TAP reading note: Longitudinal analysis of blood markers reveals progressive loss of resilience and predicts human lifespan limit",
    "description": "The study constructs a blood-count-based DOSI and examines age-related changes in its autocorrelation. Age-group correlation times of roughly 2–8 weeks motivate dynamic ageing markers. The proposed 120–150-year limit comes from extrapolation beyond observed ages, not direct measurement of a human lifespan limit.",
    "rights": "© The Allostasis Project. All rights reserved. Reproduction or adaptation requires separate permission, subject to applicable legal exceptions.",
    "version": "1.0",
    "updatedAt": "2026-10-29",
    "editorial": {
      "contentType": "evidence-review",
      "reviewState": "draft",
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      "updatedAt": "2026-10-29",
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          "scope": "Assisted source comparison, evidence extraction and bilingual research-note preparation. The materials consulted and unresolved scientific issues are specified in each note.",
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          "date": "2026-10-29",
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          "description": "Added the dynamic ageing-marker study, distinguishing extrapolated lifespan from observed recovery."
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      ]
    },
    "original": {
      "id": "pyrkov-2021",
      "title": "Longitudinal analysis of blood markers reveals progressive loss of resilience and predicts human lifespan limit",
      "authors": "Pyrkov TV · Avchaciov K · Tarkhov AE · Menshikov LI · Gudkov AV · Fedichev PO",
      "journal": "Nature Communications",
      "year": "2021",
      "url": "https://doi.org/10.1038/s41467-021-23014-1",
      "doi": "10.1038/s41467-021-23014-1",
      "pmid": "34035236"
    },
    "references": [
      {
        "id": "pyrkov-2021",
        "title": "Longitudinal analysis of blood markers reveals progressive loss of resilience and predicts human lifespan limit",
        "authors": "Pyrkov TV · Avchaciov K · Tarkhov AE · Menshikov LI · Gudkov AV · Fedichev PO",
        "journal": "Nature Communications",
        "year": "2021",
        "url": "https://doi.org/10.1038/s41467-021-23014-1",
        "doi": "10.1038/s41467-021-23014-1",
        "pmid": "34035236"
      }
    ],
    "sections": [
      {
        "id": "finding",
        "title": "What the study found",
        "paragraphs": [
          "The study constructs a blood-count-based DOSI and examines age-related changes in its autocorrelation. Age-group correlation times of roughly 2–8 weeks motivate dynamic ageing markers. The proposed 120–150-year limit comes from extrapolation beyond observed ages, not direct measurement of a human lifespan limit."
        ]
      },
      {
        "id": "limits",
        "title": "Scope & limitations",
        "paragraphs": [
          "NHANES modelling and UK Biobank validation; 1,082 people with longitudinal blood counts, reduced to 407 for the DOSI-selected non-frail dynamic analysis, plus separate activity data.",
          "Some longitudinal data lack clinical status, and selection on DOSI affects interpretation. Group-average autocorrelation is not an individual's observed recovery after a defined stressor. Linear extrapolation into unobserved ages cannot establish a hard biological limit."
        ]
      },
      {
        "id": "sample",
        "title": "Population & sample",
        "paragraphs": [
          "NHANES modelling and UK Biobank validation; 1,082 people with longitudinal blood counts, reduced to 407 for the DOSI-selected non-frail dynamic analysis, plus separate activity data."
        ]
      },
      {
        "id": "exposure",
        "title": "Exposure or intervention",
        "paragraphs": [
          "Blood-count mortality models, repeated-measure autocorrelation and comparisons with activity sequences."
        ]
      },
      {
        "id": "outcomes",
        "title": "Outcomes",
        "paragraphs": [
          "Mortality-model C-index of .68 in training, .67 in testing and .65 in UK Biobank; dynamic fluctuations and age associations were also analysed."
        ]
      },
      {
        "id": "duration",
        "title": "Time frame",
        "paragraphs": [
          "Source-specific repeated measurements and follow-up; correlation times are measured in weeks, while lifespan extrapolation extends beyond observed ages."
        ]
      },
      {
        "id": "funding",
        "title": "Research funding",
        "paragraphs": [
          "Supported by Gero PTE."
        ]
      },
      {
        "id": "conflicts",
        "title": "Research conflicts of interest",
        "paragraphs": [
          "Several authors were Gero employees, with additional shareholder and advisory-board relationships."
        ]
      },
      {
        "id": "basis",
        "title": "Reading scope",
        "paragraphs": [
          "Full-text DOSI dynamics, methods, Figure 3, extrapolation discussion and disclosures. All data processing and sensitivity analyses have not been independently reproduced."
        ],
        "links": [
          {
            "label": "Full text in PubMed Central",
            "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC8149842/"
          }
        ]
      }
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