Glycated hemoglobin

Glycated hemoglobin (HbA1c) in the blood test

Glycated hemoglobin is a form of hemoglobin bound to glucose. It reflects the average blood sugar level over the past 2-3 months and is the main marker of long-term diabetes control.

Key Features of HbA1c:

Diabetes compensation score (shows how well glucose levels are controlled).
Diagnosis of prediabetes and diabetes (together with glucose testing).
Predicting the risk of complications (the higher the HbA1c, the higher the risk of vascular, kidney, and nerve damage).

Norms of glycated hemoglobin

Category	HbA1c Level (%)	Interpretation
Healthy Individuals	< 5.7	Normal
Prediabetes	5.7–6.4	High risk of diabetes
Diabetes Mellitus	≥ 6.5	Confirmation of diabetes
Target Level in Diabetes	< 7.0*	Good control
High Risk of Complications	> 8.0	Poor glycemic control

Note:

* In the elderly and people with severe complications, the target HbA1c may be higher (7.5-8.5%).
Children have the same standards as adults.

Deviations from the norm

1. Elevated HbA1c (chronic hyperglycemia)

Reasons:

Type 1 or 2 diabetes mellitus (the main cause).
Prediabetes (metabolic syndrome, insulin resistance).
Uncontrolled eating (excess carbohydrates).
Chronic stress, infections (increase glucose).
Hemoglobinopathies (rarely, for example, in sickle cell anemia).

Symptoms of excess (diabetes):

Thirst, dry mouth (polydipsia).
Frequent urination (polyuria).
Weakness, fatigue.
Long healing of wounds.
Numbness in the legs (neuropathy).

How dangerous is it?

Microvascular complications: retinopathy → blindness, nephropathy → renal failure.
Macrovascular complications: heart attack, stroke.
Diabetic foot (risk of amputation).

2. Low HbA1c (chronic hypoglycemia)

Reasons:

Overdose of insulin or hypoglycemic drugs.
Insulinoma (a tumor that produces insulin).
Fasting, anorexia.
Genetic diseases (for example, congenital hyperinsulinemia).
Chronic kidney disease (rare).

Symptoms of deficiency (hypoglycemia):

Trembling, sweating, palpitations.
Dizziness, weakness.
Hunger, irritability.
Confusion, faintingspells.

How dangerous is it?

Hypoglycemic coma (life-threatening).
Brain damage from frequent episodes.

Additional tests

To clarify the diagnosis, prescribe:

Fasting blood glucose (norm: 3.3–5.5 mmol / l).
Oral glucose tolerance test (PGTT).
Fructosamine (assessment of glycemia in 2-3 weeks).
Insulin, C-peptide (if insulinoma is suspected).

What should I do if there are deviations?

If HbA1c is elevated:

A low-GI diet (vegetables, whole grains, protein).
Physical activity (reduces insulin resistance).
Hypoglycemic drugs (metformin, insulin-as prescribed by a doctor).
Self-monitoring of glucose (glucose meter).

If HbA1c is downgraded:

Correction of insulin/tablet doses.
Frequent snacking (complex carbohydrates + protein).
Examination for insulinoma (CT scan of the pancreas).

Important!

HbA1c does not reflect sharp spikes in sugar -only the average level.
A false decrease in HbA1c is possible with anemia, blood loss, and hemolysis.
Consultation with an endocrinologist is mandatory for deviations!

For the prevention of diabetes:

Control your weight.
Check your HbA1c every 3 years after age 45 (or more often if you are at risk).