Ultimate Longevity Bible

Best of

Best Biomarkers to Track in Your 40s

Last updated Mon Jun 08 2026 00:00:00 GMT+0000 (Coordinated Universal Time)· 2 min read

RCT evidenceMost listed biomarkers have outcomes-trial evidence supporting management

The shortlist

If you can only get one annual lab draw, prioritise this panel.

1. ApoB

ApoB — the single most important atherogenic biomarker. Target depends on personal lifetime risk; modern targets are tighter than legacy LDL-C targets. Trumps LDL-C when they disagree.

2. Lp(a) (one-time)

Lp(a) — ~90% genetic; measure once in a lifetime. If elevated (~20% of adults), every other CV risk factor needs tighter control.

3. HbA1c + fasting insulin

HbA1c plus fasting insulin / HOMA-IR — HbA1c gives the 3-month glucose average; insulin / HOMA-IR detects insulin resistance years earlier than HbA1c becomes abnormal.

4. hsCRP

hsCRP — chronic low-grade inflammation marker. Independent CV predictor; useful for response tracking.

5. eGFR + cystatin C

eGFR — kidney function. The combined creatinine + cystatin C equation is more accurate in muscular or low-muscle adults.

6. CAC score

Coronary artery calcium — once in the 40s (if intermediate risk). Powerful negative predictor if zero; guides intensity of management if elevated.

7. VO2max estimate

VO2max — from a wearable or treadmill estimate. Cardiorespiratory fitness predicts all-cause mortality as well as any single biomarker.

8. Grip strength

Grip strength — simple dynamometer reading. Predicts mortality and frailty trajectory.

9. Blood pressure (home)

Blood pressure — home cuff baseline matters more than single office readings.

10. Sleep apnea screening

AHI if any snoring, daytime sleepiness, witnessed apneas, or hypertension that doesn’t respond to standard therapy.

What to add if motivated

What to deprioritise

  • Single-time epigenetic-age tests (high noise; trend-only).
  • Long lists of micronutrients without specific clinical suspicion.
  • Continuous CGM in metabolically healthy adults (interesting; not outcome-changing).

Related entries

40s guide, ApoB, CAC score, VO2max, Peter Attia.

More best-of guides