Diabetes Blood Tests | HbA1c, Glucose, Insulin | Epicentre
DiabetesBlood Sugar

Diabetes and Blood Sugar Testing Before It Is Too Late

Fasting glucose, HbA1c and fasting insulin. Standard screening catches diabetes after years of damage. Fasting insulin catches insulin resistance at its earliest, most reversible stage. 4.5 million South Africans have diabetes. Half do not know.

Reviewed by Dr. Samantha Naidoo, MB ChB, FCP (SA) · Medical Director
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Who Is This Page For?

Family history of diabetes

Parent or sibling with Type 2

Overweight or gaining weight

Especially around the middle

Energy crashes

Tired after meals, afternoon slumps

Increased thirst or urination

Classic diabetes warning signs

Monitoring existing diabetes

Already diagnosed, tracking progress

Starting weight management

Need baseline blood tests before any programme

How Diabetes Develops – and When Tests Catch It

Normal

Healthy response. All markers normal.

Insulin Resistance

Body needs more insulin. Fasting insulin rises 10 – 15 years before glucose.

Pre-Diabetes

Glucose starts rising. HbA1c 5.7 – 6.4%.

Type 2 Diabetes

Pancreas cannot keep up. HbA1c ≥ 6.5%.

By the time fasting glucose or HbA1c are abnormal, insulin resistance has often been present for 10 – 15 years. Standard screening only catches diabetes at the pre-diabetes or diabetes stage. Fasting insulin catches metabolic dysfunction at the insulin resistance stage – the earliest, most reversible point.

Blood Sugar Markers Explained

Fasting Glucose

Snapshot of blood sugar right now

Blood sugar after 8+ hours without food. Basic screening marker. Varies day to day. Late marker – rises last in the progression.

HbA1c (Glycated Haemoglobin)

3-month average blood sugar

Gold standard for diabetes diagnosis and monitoring. More stable than fasting glucose. Diagnoses pre-diabetes (5.7 – 6.4%) and diabetes (≥ 6.5%). No fasting required.

Fasting Insulin

Reveals insulin resistance 10 – 15 years early

When the body becomes insulin resistant, it compensates by producing more insulin to keep glucose normal. Glucose and HbA1c stay "normal" while insulin climbs. Earliest marker – the functional medicine gold standard. Enables HOMA-IR calculation.

C-Peptide

How much insulin your pancreas is making

Helps distinguish Type 1 from Type 2. Shows whether the pancreas is overproducing (resistance) or underproducing (failure). Diagnostic marker.

What Is HOMA-IR?

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) is calculated from your fasting glucose and fasting insulin results. It is the gold standard for quantifying insulin resistance.

Under 1.0: optimal sensitivity. 1.0 – 2.0: early insulin resistance – the ideal time for lifestyle intervention. Above 2.0: significant resistance. Above 3.0: severe. Epicentre's ODx report calculates HOMA-IR automatically when fasting insulin is included in your panel.

Diabetes Testing Packages

Screening

Diabetes Screening Package

Basic fasting glucose test. Quick and affordable first check. Fasting required (8 – 12 hours).

Fasting Glucose
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Diabetes Monitoring Package

HbA1c plus random glucose. The standard monitoring panel for diagnosed diabetics. Test every 3 months. No fasting required.

HbA1cRandom Glucose
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Early Detection (Includes Fasting Insulin)

ODx Vital Package

Glucose, HbA1c plus metabolic markers: lipids, inflammation, vitamins, organ function. Better than glucose alone – shows your 3-month average and metabolic context. Fasting required.

Fasting GlucoseHbA1cLipogramCRPVitamin DB12FerritinFBC+more
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ODx Max Package

Includes fasting insulin – detects insulin resistance 10 – 15 years before standard tests. Plus full metabolic panel, hormones, cortisol, homocysteine and 30+ markers. HOMA-IR calculated automatically. Fasting required.

Fasting GlucoseHbA1cFasting InsulinCortisolLipogramHomocysteineTSHCRP+25 more
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ODx Ultimate Package

Everything: fasting insulin, C-peptide, full hormones, inflammation, minerals, 50+ markers. The most comprehensive metabolic investigation. Fasting required.

Fasting GlucoseHbA1cFasting InsulinC-PeptideFull HormonesInflammationMinerals50+ total
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Comprehensive Wellness

Anti-Ageing Health Package

R4,422

HbA1c, glucose plus lipids, inflammation, hormones and organ function. Monitors diabetes alongside cardiovascular risk and overall metabolic health.

HbA1cGlucoseLipogramTSHCortisolVitamin DLFTKidney Function+10 more
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Which package? For basic screening: Diabetes Screening (fasting glucose only). For monitoring: Diabetes Monitoring (HbA1c every 3 months). For early detection of insulin resistance: ODx Max (includes fasting insulin and HOMA-IR). Starting a weight management programme? The ODx Max provides the baseline your doctor needs. Or WhatsApp us.

Fasting instructions: For fasting glucose and fasting insulin, fast 8 – 12 hours. Water is fine. Black coffee is acceptable. HbA1c does not require fasting. Morning testing is recommended for the most accurate results.

All packages: Payflex available (4 interest-free instalments). 10% student discount. 10% pensioner discount. All prices include VAT. ODx functional health report included free with every blood test.

Frequently Asked Questions

What is the difference between fasting glucose and HbA1c?
Fasting glucose is a snapshot of your blood sugar right now (varies day to day). HbA1c shows your average over 2 – 3 months (gold standard for diagnosis). Both can be "normal" while fasting insulin is already elevated – which is why fasting insulin is the earliest marker.
Why test fasting insulin if my glucose is normal?
When insulin resistance develops, the body compensates by producing more insulin to keep glucose normal. This works for 10 – 15 years. By the time glucose or HbA1c are abnormal, insulin resistance has been present for over a decade. Fasting insulin catches it at the earliest, most reversible stage.
Do I need to fast for all diabetes tests?
Fasting required (8 – 12 hours, water fine): fasting glucose and fasting insulin. No fasting: HbA1c and random glucose. Morning testing after an overnight fast is recommended for comprehensive panels.
How often should I test my HbA1c?
Diagnosed: every 3 months. Pre-diabetic: every 6 months. Screening with risk factors (family history, overweight): annually.
What is HOMA-IR?
Calculated from fasting glucose and fasting insulin. Under 1.0: optimal. 1.0 – 2.0: early insulin resistance (ideal intervention point). Above 2.0: significant resistance. Above 3.0: severe. Epicentre's ODx report calculates this automatically when fasting insulin is included.
What tests do I need before starting a weight management programme?
Baseline tests should include HbA1c, fasting glucose, fasting insulin, TSH (thyroid), kidney function, liver function and lipids. The ODx Max Package covers all of these. Epicentre is a diagnostic laboratory and does not prescribe medication. Weight management monitoring guide.

Related

Weight Management Monitoring Hormone Testing Fatigue Testing All Packages

Pre-Diabetes Is Reversible. But Only If You Catch It.

Fasting insulin detects insulin resistance 10 – 15 years before standard tests. No doctor's referral.

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Walk-in labs: Observatory (Cape Town), Hillcrest (Durban), Parktown North (Johannesburg). Mon – Fri, 08:30 – 16:00. Practice #1117394.

SN
Medically reviewed by Dr. Samantha Naidoo
MB ChB, FCP (SA) · Medical Director, Epicentre Laboratories

Epicentre Walk-In Labs does not provide medical diagnoses. For diagnoses and advice, consult your healthcare practitioner.

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