10 Biomarkers That Actually Predict Longevity

Your standard annual physical is built around what insurance will reimburse, not around what predicts mortality. That's not a conspiracy — it's just how the system evolved. The labs that correlate most tightly with cardiovascular events, metabolic disease, and all-cause mortality are often one tier deeper than the panel your primary care doc ordered last spring.

Below are the ten biomarkers with the strongest evidence base for predicting longevity, why each one matters, and which ones your last physical almost certainly skipped.

1. ApoB — the lipid number that actually matters

Apolipoprotein B counts the number of atherogenic particles in your blood — every LDL, VLDL, and Lp(a) particle carries exactly one ApoB. Standard LDL-C measures cholesterol content; ApoB measures particle count. When the two disagree (and they often do in insulin-resistant patients), particle count wins.

The Mendelian randomization data is hard to argue with: ApoB outperforms LDL-C and non-HDL-C as a predictor of coronary events (Sniderman et al., JAMA Cardiology, 2019). Most annual physicals don't order it.

2. Lp(a) — the genetic risk almost nobody checks

Lipoprotein(a) is genetically determined, stable across your lifetime, and elevated in roughly 1 in 5 adults. High Lp(a) independently raises risk for atherosclerotic cardiovascular disease and aortic stenosis, and no amount of clean eating will move it meaningfully.

You only need to measure it once. The fact that most people never have is the closest thing in preventive cardiology to a free lunch missed.

3. hs-CRP — inflammation, quantified

High-sensitivity C-reactive protein is a downstream marker of systemic inflammation. Elevated hs-CRP predicts cardiovascular events independently of LDL — the JUPITER trial demonstrated this directly, showing that statin therapy reduced events in patients with normal LDL but elevated hs-CRP (Ridker et al., NEJM, 2008).

A value under 1.0 mg/L is ideal. Over 3.0 mg/L deserves a conversation about what's driving it — visceral fat, periodontal disease, autoimmune activity, or sleep apnea are common culprits.

4. HbA1c — three months of glucose, in one number

Fasting glucose tells you what your blood sugar looked like this morning. HbA1c tells you the average over the previous ~90 days. The relationship between HbA1c and all-cause mortality is roughly U-shaped, with the nadir somewhere between 5.0 and 5.6%.

Many physicals still skip A1c in non-diabetic patients. That's a missed opportunity, because the metabolic dysfunction window — A1c 5.7 to 6.4% — is exactly where lifestyle changes still work and medications usually aren't needed yet.

5. Fasting insulin — the earliest signal of metabolic trouble

Fasting insulin elevates years before fasting glucose does. By the time your glucose is abnormal, your pancreas has been compensating for a long time. A fasting insulin under 7 µIU/mL in a non-fasted state suggests reasonable insulin sensitivity; values above 10–12 µIU/mL in the fasted state warrant attention.

Almost no standard physical includes this. It should.

{callout: The takeaway} If your annual physical didn't include ApoB, Lp(a), hs-CRP, fasting insulin, and HbA1c, you have a partial picture — not a complete one. The biomarkers with the strongest mortality links are mostly the ones not being ordered.

6. GGT — the liver enzyme that does more than flag drinkers

Gamma-glutamyl transferase is often dismissed as the "alcohol enzyme," but it's also a sensitive marker of oxidative stress, hepatic fat, and metabolic syndrome. Elevated GGT independently predicts cardiovascular mortality and type 2 diabetes, even in patients who don't drink (Kunutsor et al., Atherosclerosis, 2014).

If your ALT and AST are normal but your GGT is creeping up, that's usually the earliest signal of non-alcoholic fatty liver disease.

7. Uric acid — the gout marker that predicts more than gout

Elevated uric acid correlates with hypertension, metabolic syndrome, kidney disease, and all-cause mortality. The mechanism is partly oxidative stress, partly endothelial dysfunction, partly insulin resistance.

You don't need to have had a gout flare for high uric acid to matter. A value persistently above 6.0 mg/dL (women) or 7.0 mg/dL (men) deserves attention.

8. Homocysteine — cheap, useful, ignored

Homocysteine reflects methylation status and B-vitamin sufficiency (specifically B12, B6, and folate). Elevated homocysteine is associated with cardiovascular disease, cognitive decline, and brain atrophy in older adults.

The test costs almost nothing. Treatment — when warranted — is usually inexpensive B-vitamin supplementation. The reason it's not on standard panels is mostly inertia.

9. Vitamin D (25-OH) — the one supplement marker worth tracking

Vitamin D deficiency is associated with increased all-cause mortality, though the causal picture is messier than the supplement industry suggests. Most adults benefit from a 25-OH vitamin D level between 30 and 60 ng/mL.

Levels under 20 ng/mL are clearly deficient. Levels over 100 ng/mL are unnecessary and can cause harm. This is one of the few labs where the supplement aisle and the evidence base actually agree — within a narrow range.

10. eGFR with cystatin C — kidney function, done right

Standard eGFR is calculated from creatinine, which is influenced by muscle mass. Muscular patients can look like they have impaired kidney function when they don't; sarcopenic older adults can look fine when their kidneys are actually struggling.

Cystatin C–based eGFR is independent of muscle mass and is a stronger predictor of cardiovascular and all-cause mortality (Shlipak et al., NEJM, 2013). It costs a few dollars more. It's almost never ordered.

Why your annual physical misses half of these

A few honest reasons:

• Reimbursement. Many of these aren't reliably covered for asymptomatic adults, so primary care doesn't reflexively order them.
• Time. A 15-minute visit doesn't accommodate a long conversation about ApoB versus LDL-C.
• Guidelines lag evidence. ApoB has been the better marker for over a decade; major US guidelines only recently caught up.
• "Normal" lab ranges are population averages, not optimal ranges. A glucose of 99 mg/dL is "normal." It's also not where you want to be at 45.

The labs your insurance reimburses and the labs that predict your lifespan are overlapping circles, not the same circle.

How to actually get these run

You have three reasonable paths. You can ask your primary care doctor directly and explain why you want each one — some will order them, some won't. You can order them yourself through a direct-access lab service. Or, if you're already working with a telehealth clinician on hormones, weight, or metabolic health, the markers worth having on file before a serious protocol typically include most of this list.

If you choose to do bloodwork through DirectCare AI, the markers we look at first depend on what you're being treated for — but the longevity-relevant panel above is the one most patients ask about second, after their initial protocol is dialed in.

What to do with the results

Don't panic at one out-of-range value. Biomarkers move with sleep, illness, recent training, hydration, and the lab itself. The pattern matters more than any single number, and the trajectory over time matters more than the pattern.

The point of measuring isn't to collect numbers. It's to find the two or three levers that, in your specific physiology, will move your risk curve the most over the next decade — and then pull them.

Editorial disclosure: This article is for informational purposes only and does not constitute medical advice. All treatments at DirectCare AI are prescribed by US-licensed clinicians based on individual medical evaluation. Compounded medications are not FDA-approved as finished products; their active ingredients are individually FDA-approved. Always consult a US-licensed clinician before starting or changing any therapy.