Which blood biomarkers actually matter for longevity?

Short answer: for predicting and improving healthy lifespan, focus first on cardiometabolic, inflammatory, kidney/liver, and metabolic-aging biomarkers — because they are the strongest, actionable predictors of morbidity and mortality. Below I list the highest-priority blood tests, why they matter, and where you can get them.

High‑priority biomarkers (what to test and why)

• Lipids / atherosclerosis risk
  • LDL‑C, non‑HDL, triglycerides — routine measures of heart disease risk.
  • ApoB and/or LDL‑particle number (LDL‑P) — better measures of atherogenic particle burden than LDL‑C alone.
  • Lipoprotein(a) [Lp(a)] — largely genetic, major independent risk factor; crucial to know if high.
  • Where to get them: request a lipid panel + ApoB and Lp(a) from LabCorp or Quest; NMR lipoprofile (LDL‑P) is available via LabCorp (Vantera NMR) or specialty services such as Nightingale or some cardiometabolic clinics.
• Glucose metabolism and insulin resistance
  • HbA1c, fasting glucose, fasting insulin (or HOMA‑IR) — predict diabetes and cardiovascular risk. Keeping HbA1c in the low-normal range is associated with longer healthspan.
  • Where: standard panel at Quest or LabCorp; fasting insulin sometimes needs special order.
• Inflammation
  • High‑sensitivity CRP (hs‑CRP) — simple inflammatory predictor of cardiovascular and overall mortality.
  • Interleukin‑6 (IL‑6) and GlycA (if available) — stronger predictors in research settings, but less commonly ordered.
  • Where: hs‑CRP available at Quest/LabCorp; GlycA via Nightingale; IL‑6 via specialty labs or research panels.
• Kidney and liver health
  • Creatinine/eGFR and cystatin C (if available) — kidney function is strongly tied to outcomes.
  • ALT/AST and GGT — liver health and metabolic dysfunction markers.
  • Where: routine metabolic/comprehensive metabolic panel at Quest or LabCorp; cystatin C by special request.
• Hematology and general health
  • CBC (hemoglobin, hematocrit, WBC) and albumin — anemia, immune status and low albumin are risk markers.
  • Where: CBC and CMP at LabCorp/Quest.
• Hormones (age/gender dependent)
  • Testosterone (total and free) in men; estradiol in women; DHEA-S; TSH/free T4 (thyroid).
  • Why: low or imbalanced sex hormones and thyroid dysfunction affect muscle, bone, cognition and survival.
  • Where: standard hormone panels at major labs; may need time-of-day ordering for testosterone.
• Micronutrients & metabolic risk modifiers
  • 25‑OH vitamin D, vitamin B12, folate, and homocysteine — deficiencies or high homocysteine are linked to adverse outcomes.
  • Where: Quest/LabCorp; micronutrient panels via SpectraCell (specialty micronutrient testing) or Direct­-to‑consumer kits.
• Advanced / research markers (optional)
  • Epigenetic “biological age” (DNA methylation clocks) — gives an estimate of biological age and response to interventions.
    • Where: TruDiagnostic is a leading commercial provider; Elysium offered related products; these are research‑focused but increasingly practical.
  • Telomere length — widely available but limited predictive value compared with methylation clocks.
    • Providers: TeloYears (older product), other specialty labs.
  • NMR metabolomics (detailed lipoprotein subfractions, GlycA) — Nightingale Health and LabCorp NMR services provide high‑resolution risk info.

Where to get tests and interpretation (brands/services to consider)

• LabCorp and Quest Diagnostics — large national labs. Reliable, accept physician orders; good for comprehensive metabolic panel, lipid panel, HbA1c, hs‑CRP, thyroid, hormones, Lp(a), and specialty tests like cystatin C or NMR lipoprofile.
• InsideTracker and WellnessFX — consumer-facing services that combine lab testing with personalized interpretation and lifestyle recommendations. Good if you want actionable guidance rather than raw numbers.
• Everlywell and LetsGetChecked — convenient at‑home kits for common tests (lipids, HbA1c, vitamin D, hormones). Useful for convenience but may not offer all specialty tests.
• TruDiagnostic — leading commercial epigenetic clock testing if you want DNA methylation biological‑age measures.
• Nightingale Health / LabCorp NMR (Vantera) — for advanced lipoprotein and metabolomics (GlycA and LDL‑P).
• SpectraCell — specialty micronutrient testing and intracellular nutrient panels (useful for complex deficiency workups).

How to prioritize and act

• If you can only do a few tests: get a basic metabolic panel (CMP), lipid panel + ApoB or LDL‑P, HbA1c, hs‑CRP, CBC, and 25‑OH vitamin D. Add Lp(a) once.
• Frequency: every 6–12 months for stable patients; more often if you’re making big lifestyle, medication, or supplement changes.
• Interpret results with a clinician — many markers are actionable (statins for high ApoB/LDL‑P, PCSK9 or niacin consideration for very high Lp(a) in context, lifestyle/medication for glucose control, vitamin D/B12 repletion, etc.).
• Don’t chase single numbers only — trends over time and multimarker risk (lipids + inflammation + glucose + kidney function) are what predict longevity.

Caveats

• Some tests (epigenetic age, telomere length, certain cytokines) are still research‑oriented and not yet proven to be clinical game‑changers. Use them to inform, not dictate, care.
• Genetic testing (APOE, LPA genetics) can add context but requires counseling for interpretation.

If you want, tell me:

• your age, sex, major health conditions, and whether you want at‑home vs physician‑ordered testing — I’ll give a tailored, prioritized test panel and recommended providers.