Composite Biological LegAge Index

Getting Started

Overview

Indices

Inflammation

Muscle

Bone and mineral

Glucose and insulin

Lipids

Nerve and blood vessel

Oxidative stress and fibrosis

Kidney and protein

Cartilage

Cartilage oligomeric matrix protein

The CBLAI sums seven domains of leg ageing into one score. It uses 25 biomarkers, the most of any index. 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

Domain	Biomarkers	αd
Inflammation Risk Factor (IRF)	hs-CRP, NLR, IL-6, MDA	2
Vascular & Angiogenic Function (VAF)	VEGF, MMP-9, TGF-β1	2
Musculoskeletal Health Factor (MHF)	COMP, CK-MM, Aldolase A, CTX-II	2
Bone Metabolic Function (BMF)	PTH, Ca/P ratio, Vitamin D, Osteocalcin	1
Peripheral Nerve Function (PNF)	BDNF, Substance P	1
Cardiometabolic Function (CMF)	HbA1c, TC, LDL-C, HDL-C, TG	6
Renal Filtration Factor (RFF)	Creatinine, BUN, eGFR	3

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 Risk Factor (IRF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
hs-CRP	0.2–3.0 mg·L⁻¹	1.6	0.7	↑ Bad	3.5	2.71	2.71
NLR	1.0–3.0 ratio	2	0.5	↑ Bad	3.2	2.40	2.40
IL-6	0.5–7.0 pg·mL⁻¹	3.75	1.63	↑ Bad	9.8	3.71	3.71
MDA	1.0–3.5 µmol·L⁻¹	2.25	0.63	↑ Bad	4.6	3.73	3.73

Vascular & Angiogenic Function (VAF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
VEGF	30–250 pg·mL⁻¹	140	55	Context	305.6	3.01	3.01
MMP-9	20–140 ng·mL⁻¹	80	30	↑ Bad	155.8	2.53	2.53
TGF-β1	10–40 pg·mL⁻¹	25	7.5	Context	45.8	2.77	2.77

Musculoskeletal Health Factor (MHF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
COMP	200–600 ng·mL⁻¹	400	100	↑ Bad	850	4.50	4.50
CK-MM	50–170 U·L⁻¹	110	30	↑ Bad	190	2.67	2.67
Aldolase A	1.2–7.5 U·L⁻¹	4.35	1.58	↑ Bad	8.5	2.63	2.63
CTX-II	120–450 pg·mL⁻¹	285	82.5	↑ Bad	510.7	2.74	2.74

Bone Metabolic Function (BMF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
PTH	15–65 pg·mL⁻¹	40	12.5	↑ Bad	75.3	2.82	2.82
Ca/P ratio	2.0–2.8 ratio	2.4	0.2	Normal best	2.9	2.50	2.50
Vitamin D	30–100 ng·mL⁻¹	65	17.5	↓ Bad	25.4	-2.26	2.26
Osteocalcin	11–43 ng·mL⁻¹	27	8	↓ Bad	8.9	-2.26	2.26

Peripheral Nerve Function (PNF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
BDNF	15–40 ng·mL⁻¹	27.5	6.25	↓ Bad	12.8	-2.35	2.35
Substance P	30–200 pg·mL⁻¹	115	42.5	↑ Bad	225.6	2.60	2.60

Cardiometabolic Function (CMF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
HbA1c	4.0–5.6 %	4.8	0.4	↑ Bad	7.6	7.00	7.00
TC	120–199 mg·dL⁻¹	159.5	19.8	↑ Bad	225.6	3.34	3.34
LDL-C	50–99 mg·dL⁻¹	74.5	12.3	↑ Bad	185.5	9.02	9.02
HDL-C	40–80 mg·dL⁻¹	60	10	↓ Bad	35.7	-2.43	2.43
TG	50–149 mg·dL⁻¹	99.5	24.8	↑ Bad	165.8	2.67	2.67

Renal Filtration Factor (RFF)

Biomarker	Healthy range	Mean	SD	Direction	Value	Z	\|Z\|
Creatinine	0.7–1.3 mg·dL⁻¹	1	0.15	↑ Bad	1.8	5.33	5.33
BUN	7–20 mg·dL⁻¹	13.5	3.25	↑ Bad	21.8	2.55	2.55
eGFR	90–120 mL·min⁻¹·1.73 m⁻²	105	7.5	↓ Bad	82.7	-2.97	2.97

Domain scores

Domain	Mean \|Z\|d	Wd	Mean \|Z\|d × Wd	αd	Score
IRF	3.14	0.14	0.44	2	0.88
VAF	2.77	0.12	0.34	2	0.68
MHF	3.13	0.14	0.44	2	0.87
BMF	2.46	0.11	0.27	1	0.27
PNF	2.48	0.11	0.27	1	0.27
CMF	4.89	0.22	1.06	6	6.39
RFF	3.62	0.16	0.58	3	1.75
Total	22.49	1.00	3.40		11.11

The example patient's CBLAI is 11.11.

Cardiometabolic Function adds the most to the score (6.39 of 11.11).

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.