HbA1c by age: what is a normal value after 60?

A daughter recently called us about her father's result: his HbA1c was "44" and it was keeping him up at night. On its own, that single number says little. HbA1c shows how high your blood sugar was on average over the past two to three months, and that average often reassures where a one-off finger-prick alarms.

My conviction after hundreds of these conversations: do not panic over a single value just above the line. The direction over time says more than a snapshot.

What is HbA1c?

HbA1c is a measure of your average blood sugar over roughly the past two to three months. Sugar attaches to the red blood pigment (haemoglobin) in your blood, and the higher your sugar, the more sugar attaches. So one measurement gives a picture over a longer period. You usually do not need to fast for an HbA1c test, which makes it easy to plan at a calm moment.

What is a normal HbA1c value?

In many people without diabetes, HbA1c sits below 42 mmol/mol, but the exact cut-offs are always on your lab report and can differ slightly between laboratories. According to the Diabetes Fonds and the NHG guideline that Dutch GPs follow, a value of 48 mmol/mol or higher is used as the threshold for a diabetes diagnosis. A doctor assesses your value not in isolation but together with your symptoms and your other risk factors.

These figures are an aid, not a diagnosis. The definitive thresholds and the interpretation belong with your doctor, who also looks at repeat measurements.

Does HbA1c change with age?

Sensitivity to insulin decreases in many people over the years, so blood sugar rises a little more easily. A slightly higher HbA1c later in life is therefore not unusual, but does not automatically mean illness. A doctor weighs your age into the assessment: what calls for attention in one person may fit healthy ageing in another. Thuisarts.nl, the public site of Dutch GPs, reflects the same nuance.

What is prediabetes and what can you do about it?

Prediabetes means your blood sugar is higher than normal but not yet high enough for a diabetes diagnosis. It is mainly a signal to look at your lifestyle, not a reason to panic. With attention to diet and exercise, much is often possible. The Voedingscentrum advises eating enough vegetables and wholegrain foods daily and staying active, which can favourably influence blood sugar. To see the bigger picture, read how to prevent and recognise type 2 diabetes after 60 or what changes in your blood values.

A few concrete lifestyle steps that, according to the NHG and the Diabetes Fonds, can help to influence blood sugar favourably: move for at least half an hour daily, choose wholegrain instead of white products more often, limit sugary drinks, and lose a few kilos if you are overweight. None of this is a guarantee, but with prediabetes the gain from lifestyle is often greatest. Discuss with your GP which steps suit you.

Which symptoms fit a high blood sugar?

A high blood sugar does not always cause symptoms, certainly not at the start. That is exactly why an HbA1c measurement can be useful: it makes something visible before you notice anything. If there are symptoms, they can be vague. Frequently mentioned signs are:

• more thirst and passing urine more often, including at night;
• unexplained tiredness or low energy;
• cuts that heal more slowly;
• blurred vision or more often recurring infections.

These symptoms can also have other causes. If you recognise them, discuss them with your GP and have your blood sugar checked if needed. Thuisarts.nl explains when to make contact.

What can distort an HbA1c result?

HbA1c is reliable, but not infallible. Because the value is measured on the red blood pigment, it can deviate in conditions that affect the lifespan of red blood cells, such as anaemia or a recent blood transfusion. In some forms of kidney disease the value can also be less accurate. That is why, when in doubt, a doctor also looks at your fasting glucose and your blood count. A single HbA1c is a snapshot of an average, not a final verdict.

How often should you check your HbA1c?

How often a check is worthwhile depends on your value and your risk. With a normal value and no symptoms, periodic measuring often suffices, for example once a year or every two years. If your value is in the prediabetes range, measuring more often can help to follow the trend and see the effect of lifestyle changes. You determine the right frequency together with your GP; this table is only meant as a rough guide.

How do you get your HbA1c measured?

You can have your HbA1c measured with the Levenswijs Diabetes Panel, without a referral. Alongside HbA1c, this panel also looks at fasting glucose and your kidney function, because those values are connected. A higher HbA1c sometimes goes together with a lower kidney function, which is why a doctor likes to look at the whole picture.

My advice: know your baseline and track it over time. Always discuss an abnormal result with your GP, if helpful using the explanations on Thuisarts.nl.

Would you like to have your blood sugar checked at a calm moment, without first making an appointment with your GP? At Levenswijs Health you can. The result is reviewed by a BIG-registered doctor. A blood test does not provide a diagnosis. For treatment decisions, always discuss your results with your GP.