Verbatim response from Claude
Key Blood Biomarkers for Longevity
Tier 1 - Strong Evidence
Metabolic Health
- Fasting insulin & HOMA-IR - arguably the most important; insulin resistance drives multiple aging pathways
- HbA1c - average blood sugar over ~3 months
- Fasting glucose
- Triglycerides/HDL ratio - better cardiovascular predictor than total cholesterol alone
Inflammation
- hs-CRP (high-sensitivity C-reactive protein) - chronic inflammation marker
- IL-6 - predictive of mortality in multiple studies
Organ Function
- eGFR/creatinine - kidney health
- ALT/AST - liver health
- Cystatin C - more accurate kidney aging marker than creatinine
Tier 2 - Meaningful but Context-Dependent
- ApoB - better cardiovascular risk marker than LDL
- Homocysteine - linked to cardiovascular and cognitive decline
- Vitamin D - immune and metabolic function
- Testosterone/DHEA-S - hormonal aging
- IGF-1 - growth factor balance
Getting Tested
Good options:
- Inside Tracker - analyzes results with longevity-specific ranges
- Function Health - comprehensive panel (~100 biomarkers)
- LabCorp/Quest through your doctor - most affordable
Worth skipping for most people: extensive genetic panels, exotic markers without actionable interventions
The metabolic cluster matters most - fix insulin resistance and you often improve several others simultaneously.