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Originally Posted On: https://sloanestreetsurgery.co.uk/diabetes/what-your-blood-sugar-levels-reveal-the-importance-of-testing/

What Your Blood Sugar Levels Reveal: The Importance of Testing

Hba1c – a very useful blood test

HbA1c is a blood marker which tells us your average blood glucose (sugar) level over the last 2-3 months. It is enormously useful because it helps us to diagnose Type 2 diabetes but it can also tell us if you are at risk of developing diabetes. Furthermore, if diagnosed, it is used to monitor how well you are controlling your blood sugar. It is a very practical blood test as you don’t need to fast and you can come in for it at any time of day. As your HbA1c level tells us your average blood glucose concentration over the last 2-3 months, it is a more accurate way of looking at your blood sugar control than a one-off ‘random’ test of blood glucose levels.

What does my Hba1c number mean?

Normal range- 20-42 mmol/mol

Prediabetes – 42-47 mmol/mol

Diabetes 48 mmol/mol or above (if monitoring your diabetic control, the target is usually 48-53 mmol/mol depending on what you have agreed with your doctor)

Everyone is talking about ‘continuous glucose monitoring’ (the little white patch people are sticking on their upper arm)- is this recommended?

Unfortunately, diabetes is not simply about sugar spikes and whether you have them or not. This is not a recommended way to see if you have pre-diabetes or diabetes but may be advised under supervision of a diabetes specialist to monitor sugar control once you are diagnosed.

Diabetes in a nutshell

Diabetes is a condition where your blood sugar is too high. This may be as a result of Type 1 or Type 2 diabetes:

• Type 1 diabetes: An autoimmune condition, commonly diagnosed in childhood or adolescence, where your body fights its own pancreatic cells, preventing insulin production. Insulin is required to drive glucose in your blood into your body cells so that they can function. If there isn’t enough insulin, the sugar will hang around in your blood instead. If we suspect Type 1 diabetes, we usually refer you urgently to a specialist to have this confirmed. Specialists are more likely to use fasting blood glucose tests rather than Hba1c, in this instance.
• Type 2 diabetes: The body cells have become somewhat resistant to insulin and thus they will not take in as much glucose as they should, again leaving too much sugar in your blood.

So what is the problem with too much sugar in my blood?

Unfortunately, there are a host of different complications from having high sugar levels. Common symptoms include being extremely thirsty, needing to pass urine a lot, fatigue and unintentional weight loss.  Extremely elevated levels of sugar can cause acute diabetic crises requiring hospitalisation, largely due to the risk of dehydration. They also put you at higher risk of infections. Over time, high blood sugar is a significant risk factor for heart disease, stroke, peripheral arterial disease, kidney disease, eye disease and peripheral nerve disease1. Studies are also showing that there are other lesser known complications of diabetes emerging, such as cancer, liver disease and dementia2,3,4.

What exactly is pre-diabetes?

This means your sugar levels are higher than normal but not high enough to meet the criteria for diabetes. It means you are at risk of developing diabetes and also constitutes an independent risk factor for developing heart disease and stroke5. The great benefit of knowing you have pre-diabetes is that it is possible to make lifestyle changes to reverse it.

When is Hba1c testing recommended?

Everyone should test their Hba1c at around 40 years old regardless of their health and risk factors. If normal, this can serve as a useful baseline result to see how you continue to control blood sugar levels over time.

You should consider testing your Hba1C as early as your 30’s if you have:

• a strong family history of diabetes e.g. a first degree relative such as a parent or sibling. This is because your chance of being diagnosed with diabetes is 15% if you have one parent with Type 2 diabetes and 75% if both parents have Type 2 diabetes6.
• previously been diagnosed with gestational diabetes (diabetes in pregnancy).
• previously been told you have any of the following conditions: being overweight or obese (BMI 25+), high blood pressure, high cholesterol, heart disease, arterial disease, kidney disease, fatty liver disease, polycystic ovarian syndrome (PCOS).
• been taking daily steroid medication for several months or more.

Who is Hba1c not suitable for?

• If you are acutely unwell.
• If you have a diagnosis of sickle cell anaemia or thalassaemia.

What can I do about having an elevated Hba1c level?

The good news is that there are lots of things you can do.

If you have prediabetes or your Hba1c has increased from a previous result, we will want to assess your other cardiovascular risk factors like weight, blood pressure, cholesterol and family history. The management of prediabetes focuses on making key lifestyle changes, including reducing your intake of sugar, carbohydrates and processed foods, increasing physical activity, and achieving weight loss if you are overweight. Additionally, a referral to a dietitian may be recommended to help you develop a personalised action plan.

If your Hba1c falls within the diabetic range, the above lifestyle changes will be hugely important, and medication is generally also advised. Medications for diabetes include one or more types of oral tablets taken daily. With worsening control (higher Hba1c levels), weekly injections and/or insulin are recommended. Insulin is always required in type 1 diabetes where there is a problem with insulin production. It is reserved for those with poorly controlled type 2 diabetes where several medications have failed and insulin production eventually fails too.

How big a problem is diabetes? The case for getting tested…

Regrettably, diabetes is a large and growing problem in the UK. In 2019, 3.9 million people were diagnosed with diabetes but it was estimated that roughly 1 million more people were living with diabetes, unaware6.

Unfortunately, the longer someone lives with high blood sugar, the more at risk they are of developing diabetic complications. A quick and easy ‘Hba1c’ blood test at 40 years old (or earlier if you have risk factors) can help diagnose pre-diabetes or diabetes. With the right help, you can reduce your sugar levels and often reverse these conditions. Please note Hba1c testing is part of our annual medicals and general health check-ups. Otherwise, it is really worth booking an appointment if you are yet to do so.

To book an appointment online click here or call us on 0207 245 3999. 

Article produced by Sloane Street Surgery, a private GP practice in London that provides world-class private healthcare for patients in Chelsea, Knightsbridge, Belgravia, West London, Hampshire, and beyond.

1Fowler, M. J. Microvascular and macrovascular complications of diabetes. Clin. Diabetes 26, 77–82 (2008).

2Tolman, K. G., Fonseca, V., Dalpiaz, A. & Tan, M. H. Spectrum of liver disease in type 2 diabetes and management of patients with diabetes and liver disease. Diabetes Care 30, 734–743 (2007).

3Chatterjee, S. et al. Type 2 diabetes as a risk factor for dementia in women compared with men: a pooled analysis of 2.3 million people comprising more than 100,000 cases of dementia. Diabetes Care 39, 300–307 (2016).

4Tsilidis, K. K., Kasimis, J. C., Lopez, D. S., Ntzani, E. E. & Ioannidis, J. P. Type 2 diabetes and cancer: umbrella review of meta-analyses of observational studies. BMJ 350, g7607 (2015).

5Ford ES, Zhao G, Li C. Pre-diabetes and the risk for cardiovascular disease: a systematic review of the evidence. J Am Coll Cardiol. 2010 Mar 30;55(13):1310-7. doi: 10.1016/j.jacc.2009.10.060. PMID: 20338491.

6Diabetes UK  (2020) Diabetes risk factors. Diabetes UK. https://www.diabetes.org.uk/

7Diabetes UK (2019b) Diabetes prevalence 2019. Diabetes UK. https://www.diabetes.org.uk/