Biomarkers
Laboratory and physiological markers used to monitor health, aging and physical performance.
4.7HbA1c (Glycated Hemoglobin)
A biomarker reflecting average blood glucose over the past 2–3 months — the gold standard for diagnosing and monitoring diabetes, far more stable than a single glucose measurement.
4.5Ferritin
An iron-storage protein whose blood level is the best available indicator of the body's iron stores — though it can be falsely elevated by inflammation, which complicates straightforward interpretation.
4.5CRP and hs-CRP
A protein produced by the liver in response to inflammation — in its high-sensitivity form (hs-CRP) it has become one of the most widely studied additional markers of cardiovascular risk.
4.0OMAA Score
The OMAA Score (Oral Microbiome Aging Acceleration) is a numerical index calculated as the difference between the age predicted from an oral microbiome sample and a person's actual age — in the study that introduced it, it was linked to elevated mortality and frailty risk.
3.9MicroAge
A machine-learning model that estimates biological age from the composition of the saliva microbiome — a very early, emerging approach to aging biomarkers, distinct from the mortality-focused OMAA Score.
4.1Epigenetic Age Acceleration
The difference between an age estimated from a DNA methylation pattern and chronological age — one of the most statistically well-documented aging biomarkers, strongly linked to mortality in population studies, though still of limited diagnostic value for a single individual.
4.2Organ Biological Age
The concept that individual organs — the heart, brain, liver, or kidneys — can age at markedly different rates within the same person, measurable through analysis of tissue-specific plasma proteins rather than a single, averaged 'biological age' score.
4.2Biological Age Clocks
An umbrella term covering very different methods for estimating the 'true' pace at which an organism is aging — from well-validated second-generation epigenetic clocks to far less proven commercial tests based on glycans or the microbiome. Not all of them carry a comparable level of evidence.
4.1Intrinsic Capacity
A World Health Organization (WHO) concept defining 'true' functional aging as the sum of five domains of physical and mental ability — an alternative to molecular biomarkers, assessed in a clinical exam rather than a lab.
4.0GlycanAge
A commercial biological-age test based on the glycosylation pattern of IgG antibodies — it grew out of real research from the Croatian Genos/Gordan Lauc group, but independent validation of the product itself remains limited.
4.6Can insulin resistance occur in a lean man?
Yes — insulin resistance can affect men with a normal BMI too, if fat accumulates mainly viscerally and inside internal organs rather than under the skin. We explain the TOFI phenomenon (thin-outside-fat-inside) and why BMI alone isn't enough to assess metabolic risk.
4.5Can insulin resistance occur without being overweight?
Yes — insulin resistance can occur even in people with no excess body fat at all, including visceral fat. We explain the rarer, but real, mechanisms that operate independently of fat: genetic variants in the insulin signaling pathway, chronic sleep deprivation, chronic stress, and physical inactivity.
4.7Why is insulin high despite normal glucose?
Elevated insulin with normal fasting glucose is most often compensatory hyperinsulinemia — the pancreas produces more insulin to keep glucose normal despite the tissues' weaker response. It's an early warning sign that the HOMA-IR index can catch long before glucose itself ever rises.
4.6Can high insulin lower SHBG?
Yes — insulin directly suppresses SHBG production in the liver, making chronically elevated insulin one of the best-documented causes of low SHBG. This is an important bridge between insulin resistance and the interpretation of testosterone results, in both men and women.
4.6Can Iron Deficiency Occur Without Anemia?
Yes — iron deficiency develops in stages, and depleted stores (low ferritin) can precede a drop in hemoglobin by months, which is why fatigue and hair loss can appear with a completely normal blood count.
4.6Why Is Ferritin Low Despite a Normal Blood Count?
Because ferritin reflects iron stores, which are depleted first — changes in the blood count show up later, only once the bone marrow can no longer compensate for the shortage of raw material for red-cell production.
4.6Does Normal Ferritin Rule Out Iron Deficiency?
Not always — ferritin is also an acute-phase protein, so inflammation, infection, liver disease, or obesity can artificially raise its result and mask a genuine iron deficiency.
4.6What Does Low Transferrin Saturation Mean?
Low transferrin saturation means the protein that transports iron in the blood is mostly 'empty' — too little iron is circulating in a usable form, making it one of the earliest signals of functional iron deficiency.
4.5Why Is RDW High Despite a Normal Blood Count?
RDW rises when red blood cells start varying in size more than usual — it can signal early iron deficiency before MCV changes, or, less often, a masked mixed deficiency (iron plus B12/folate).
4.5Does Low MCH Always Mean Iron Deficiency?
No — low MCH is most often caused by iron deficiency, but thalassemia trait, anemia of chronic disease, and chronic lead exposure produce the same picture, so telling them apart requires additional testing.
4.5Can Low MCV Occur With Normal Hemoglobin?
Yes — this is microcytosis without anemia: the body compensates for smaller red cells by producing more of them, keeping hemoglobin normal despite abnormally sized cells. The most common causes are mild iron deficiency or thalassemia trait.