Health Tips

Diabetes mellitus

Diabetes mellitus is characterised by abnormally high blood glucose level for an extended period of time and the disrupted metabolism of carbohydrate, fat and protein. This happened when the body failed to secrete a hormone called insulin and/or your body cells are resistant towards the effect of the secreted insulin (called insulin resistance). 

💡Insulin is a hormone secreted by the organ called the pancreas. Insulin is a hormone that is responsible for allowing glucose in the blood to enter cells, providing them with the energy to function. Insulin also assists in breaking down fats or proteins for energy. 

What is HbA1c?

The glycated haemoglobin, HbA1c, develops when haemoglobin, a protein within red blood cells that carries oxygen throughout your body, joins with glucose in the blood, becoming ‘glycated’.

Image credit: Biologic Models

Hence, the amount of glucose that combines with this protein is directly proportional to the total amount of sugar that is in your system at that time.

Because red blood cells in the human body survive for 8-12 weeks before renewal, the HbA1c test is an important blood test that gives a good indication of how well your diabetes is being controlled in the past 2-3 months. 

If your blood sugar levels have been high in recent weeks, your HbA1c will also be greater.

HbA1c Testing in Diagnosing Diabetes

An HbA1c reading can be taken from blood from a finger but is often taken from a blood sample that is taken from your arm.

On the other hand, the blood glucose level is the concentration of glucose in your blood at a single point in time, i.e. the very moment of the test. This is measured using a fasting plasma glucose test, which can be carried out using blood taken from a finger or can be taken from a blood sample from the arm.

Together with the fasting plasma glucose test, the HbA1c test is one of the main ways in which type 2 diabetes mellitus is diagnosed.

According to the World Health Organisation (WHO), an HbA1c of 6.5% is recommended as the cut point for diagnosing diabetes. A value of less than 6.5%, however, does not exclude diabetes diagnosed using glucose tests. 

To be more exact,

• HbA1c below 42 mmol/mol (6.0%): Non-diabetic

• HbA1c between 42 and 47 mmol/mol (6.0–6.4%): Impaired glucose regulation (IGR) or Prediabetes

• HbA1c of 48 mmol/mol (6.5%) or over: Type 2 diabetes mellitus

Your doctor should inform you of the target HbA1c you should achieve.

It’s worth noting that HbA1c is not used to diagnose gestational diabetes (i.e. first-time diagnosed diabetes during pregnancy). Instead, an oral glucose tolerance test (OGTT) is used.

How often should I carry out the HbA1c test?

If you have diabetes, you are advised to get an HbA1c test every 3-6 months. Your doctor is likely to advise you get an HbA1c test every 3 months if your HbA1c reading is above the target; every 6 months if your diabetes is well-controlled and stable.

Image credit: Diabetes.co.uk
 

What are the benefits of lowering your HbA1c?

There are many benefits in lowering HbA1c. For starter, HbA1c reading is a good predictor to many diabetes complications. 

A study has found out that by lowering HbA1c, one is less likely to experience vision loss (retinopathy) and kidney damage (nephropathy) as a result of diabetes.

Not only that, but a well-controlled HbA1c reading also reduces the risks of heart attack, stroke and amputations among the diabetic patient. 

Some of the factors that influence HbA1c and its measurement

Source: WHO - Use of Glycated Haemoglobin (HbA1c) in the Diagnosis of Diabetes Mellitus 

In these situations, HbA1c is not recommended, and alternatives such as self-monitoring blood glucose (SMBG) should be considered. In addition, HbA1c does not provide information on glucose variability and does not capture hypoglycaemia. In such circumstances, a combination of SMBG and A1c is appropriate.

💡Hypoglycaemia happens when the blood glucose level falls below the normal level. This may result in a variety of symptoms including clumsiness, trouble talking, confusion, loss of consciousness, seizures or death.

Here are what you can do to lower your HbA1c:

• Limit your total carbohydrate intake of the day based on the doctor’s advice.

• Monitor your total intake of carbohydrate in a day. You may consult a dietician or doctor for this. 

• Adopt a low-glycaemic intake diet. 

• Lose weight if you are overweight or obese.

• Maintain an active lifestyle by exercising 5 days a week. Both aerobic and resistance exercise are beneficial for patients with diabetes, and it is optimal to do both types of exercise.

• Strictly adhere to your medication regimen and do not skip dose unless under the supervision of a healthcare professional.

• Attend your follow-up with the doctor regularly, particularly follow-up for foot check, eye check etc.

Written by

Ms Joyce Toh