The CBOAI sums five domains of orthopaedic ageing into one score. It uses 15 biomarkers. A higher score means more of the panel sits outside its healthy range, with the most weight on the domains that matter most for this index.

See Indices for how every index is calculated.

Domains

DomainBiomarkersαd
Inflammation & Immune Aging (IIA)hs-CRP, NLR, IL-66
Endocrine-Mineral Regulation (EMR)PTH, Ca/P ratio, Vitamin D1
Bone & Cartilage Output (BCO)PINP, CTX-II, Osteocalcin1
Muscle-ECM Degeneration (M-ECMD)CK-MM, Aldolase A, MMP-9, MDA5
Neurovascular Coupling (NVC)VEGF, BDNF3

αd is the fixed priority of each domain in this index.

Example

These are the results of one example patient, worked through step by step.

Biomarker Z-scores

Each result becomes a Z-score: (value − mean) / SD, with the mean and SD taken from the healthy range.

Inflammation & Immune Aging (IIA)

BiomarkerHealthy rangeMeanSDDirectionValueZ|Z|
hs-CRP0.2–3.0 mg·L⁻¹1.60.7↑ Bad3.52.712.71
NLR1.0–3.0 ratio20.5↑ Bad3.22.402.40
IL-60.5–7.0 pg·mL⁻¹3.751.63↑ Bad9.83.713.71

Endocrine-Mineral Regulation (EMR)

BiomarkerHealthy rangeMeanSDDirectionValueZ|Z|
PTH15–65 pg·mL⁻¹4012.5↑ Bad75.32.822.82
Ca/P ratio2.0–2.8 ratio2.40.2Normal best2.92.502.50
Vitamin D30–100 ng·mL⁻¹6517.5↓ Bad25.4-2.262.26

Bone & Cartilage Output (BCO)

BiomarkerHealthy rangeMeanSDDirectionValueZ|Z|
PINP20–80 ng·mL⁻¹5015↓ Bad9.7-2.692.69
CTX-II120–450 pg·mL⁻¹28582.5↑ Bad510.72.742.74
Osteocalcin11–43 ng·mL⁻¹278↓ Bad8.9-2.262.26

Muscle-ECM Degeneration (M-ECMD)

BiomarkerHealthy rangeMeanSDDirectionValueZ|Z|
CK-MM50–170 U·L⁻¹11030↑ Bad1902.672.67
Aldolase A1.2–7.5 U·L⁻¹4.351.58↑ Bad8.52.632.63
MMP-920–140 ng·mL⁻¹8030↑ Bad155.82.532.53
MDA1.0–3.5 µmol·L⁻¹2.250.63↑ Bad4.63.733.73

Neurovascular Coupling (NVC)

BiomarkerHealthy rangeMeanSDDirectionValueZ|Z|
VEGF30–250 pg·mL⁻¹14055Context305.63.013.01
BDNF15–40 ng·mL⁻¹27.56.25↓ Bad12.8-2.352.35

Domain scores

DomainMean |Z|dWdMean |Z|d × WdαdScore
IIA2.940.220.6463.82
EMR2.530.190.4710.47
BCO2.560.190.4810.48
M-ECMD2.890.210.6153.07
NVC2.680.200.5331.59
Total13.601.002.739.42

The example patient's CBOAI is 9.42.

Inflammation & Immune Aging adds the most to the score (3.82 of 9.42).

Notes

  • The mean and SD come from the healthy range, so a result inside the range has a |Z| of 2 or less.
  • The score has no fixed upper limit. Compare it over time for the same person, not between indices.
  • This page is general information, not medical advice. Discuss results with a clinician.