Biomarker reference

Energy & metabolic

Glucose, insulin and the full lipid picture: the pattern behind afternoon crashes, years before it reads as diabetes risk.

Metabolic markers describe how well your body converts food into usable energy, and they move years before a diabetes diagnosis becomes possible. The reason is compensation: when cells begin resisting insulin, the pancreas responds by producing more of it, and blood glucose stays normal for years while the amount of insulin required to hold it there climbs steadily. Glucose-based tests — fasting sugar and HbA1c, which is what a standard checkup measures — only register once that compensation starts to fail. Fasting insulin and HOMA-IR register at the beginning. This distinction is the whole argument for measuring them in India, where 15.3% of adults have prediabetes, more than the 11.4% who have diabetes, and where 42% of those with already-elevated blood sugar did not know it. The reversible window is the one nobody is measuring.

Why are these markers read together?

No marker in this group means much on its own. Energy & metabolic covers 29 of the measurements in the Peak Brain panel, and a physician reads them as a pattern — one value at the edge of a reference range means something quite different depending on what the others are doing.

Fasting insulin and glucose are only interpretable as a pair. Normal glucose achieved with high insulin and normal glucose achieved with low insulin describe completely different people, and HOMA-IR is the ratio that distinguishes them.
HbA1c is the diagnostic test but the laggard: it describes the last three months of average glucose, by which point the metabolic pattern has usually been established for years.
Liver markers sit in this group because fatty liver is a metabolic disease. It affects an estimated 38.6% of Indian adults and is a consequence of insulin resistance more often than of alcohol.

What does this group explain?

The 3pm crash, the post-lunch fog, and the weight that gathers at the waist while the scale barely moves.
Why a normal BMI is weak reassurance in Indians, who develop insulin resistance at lower body weights than Western populations.
Whether a dietary change is actually working, months before HbA1c would show it.

Energy & metabolic: marker explanations

Fasting insulin

Fasting insulin measures how much insulin the pancreas is releasing to hold blood glucose steady after an overnight fast.

HOMA-IR

HOMA-IR is a calculated index that combines fasting glucose and fasting insulin into a single number describing how resistant the body has become to its own insulin.

HbA1c

HbA1c measures the proportion of haemoglobin in your red blood cells that has sugar attached to it.

Also measured in this group

These markers are included in the panel and read alongside the ones above. They have no standalone reference page, because outside the context of a full panel there is little useful to say about them individually — and a page that exists only to fill a URL is worse than no page.

Fasting glucose — morning baseline
C-peptide — how hard the pancreas works
Post-load glucose — how fast you clear sugar
Total cholesterol — the headline number
LDL cholesterol — standard risk marker
HDL cholesterol — clearance capacity
Triglycerides — sugar and alcohol load
VLDL cholesterol — the triglyceride carrier
Non-HDL cholesterol — everything atherogenic
TG:HDL ratio — metabolic flexibility
Total:HDL ratio — the quick risk read
Uric acid — fructose and purine load
ALT — liver strain
AST — liver and muscle
AST:ALT ratio — pattern, not just level
GGT — alcohol and fatty liver
Alkaline phosphatase — bile and bone turnover
Albumin — protein status
Globulin — immune protein fraction
A:G ratio — protein balance
Total protein — nutrition baseline
Total bilirubin — clearance check
Direct bilirubin — where the load sits
Indirect bilirubin — the unconjugated share
Amylase — pancreas, first pass
Lipase — the more specific one

Who reviews this group

Reviewer assignment follows speciality. Pages in this group are assigned to Dr. Nitesh Arora (MD, DM) and Dr. Alfia Kaki (MD, PGC), and each page carries a byline naming its reviewer and the date of review.

Dr. Nitesh Arora — Interventional Cardiology
Dr. Alfia Kaki — Internal Medicine, Rheumatic & Musculoskeletal Medicine

Energy & metabolic: common questions

Can I have insulin resistance with a normal HbA1c?

Yes, and it is the most common presentation. The body maintains normal average glucose by producing progressively more insulin, so HbA1c stays in range throughout the phase when insulin resistance is developing and is most reversible. Fasting insulin and HOMA-IR are the markers that show it.

How long before metabolic markers respond to change?

Faster than most people expect. Fasting insulin and HOMA-IR often move measurably within eight to twelve weeks of a genuine change in diet, visceral fat and training. HbA1c lags by design, because it averages three months of glucose.

Why is fasting insulin not in a standard checkup package?

Because those packages are built to diagnose established disease at scale, and glucose and HbA1c are cheaper and sufficient for that. Fasting insulin detects the years-long phase before disease, which is a different job from the one a diagnostic panel is designed to do.

The programme

One marker rarely answers the question.

Peak Brain draws a full blood and urine panel at your home, has a licensed physician read every marker together rather than one at a time, and turns what they find into a ranked 90-day protocol with a retest at the end.

How the programme works