Reading Your CMP
CMP — Comprehensive Metabolic Panel
The CMP covers glucose, electrolytes, kidney function (BUN, creatinine), and liver function (ALT, AST, bilirubin, albumin). It's your organ-function snapshot. Reading it well lets you spot pre-diabetes, early kidney stress, and metabolic fatty liver years before they announce themselves.
Fasting glucose — the too-high-but-normal trap
Reference ranges call fasting glucose "normal" up to 99 mg/dL. Outcome-based data says mortality starts rising at glucose above 90–95. Anyone consistently in the 95–100 range is pre-pre-diabetic — a category many clinicians won't flag but longevity practitioners will.
ALT — the fatty liver signal
ALT (alanine aminotransferase) is a liver enzyme. Textbook "normal" goes to 40 U/L. Longevity-optimal is under 20–25 for women, 30 for men. Values in the 30–40 range are often dismissed as normal by PCPs but almost always mean MASLD (metabolic fatty liver). Stealth problem, very common.
Order these by fasting glucose → diabetes
Arrange from optimal (lowest) to diabetic (highest).
eGFR — the kidney number to watch trending
Estimated GFR (glomerular filtration rate) measures kidney function. Normal >90, CKD stage 2 is 60–89, stage 3 is 30–59. Everyone's eGFR drops ~1/year after 30. What matters is whether YOUR trajectory is normal. A single year-on-year drop of 5+ points deserves attention.
Key Takeaway
The CMP holds several stealth findings that slip past standard interpretation — fasting glucose creeping into the mid-90s, ALT in the low 30s suggesting fatty liver, eGFR trending down faster than age predicts. Read your own panel with tighter ranges than your PCP uses.