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HbA1c and TIME IN RANGE: what you should know

HbA1c and TIME IN RANGE: what you should know?

India has suffered a lot this one year. Lockdowns have been imposed to stop the escalating spread of Covid-19 infection. Hospitals are overflowing with patients needing oxygen, anti-virals, and steroids to battle the cytokine storm. Amidst all this, the Covid warriors have one major hurdle while treating the patient besides the viral load and the severity of lung infection: uncontrolled diabetes.

The South Asian phenotype which makes us more susceptible to diabetes, has also made us more susceptible to more severe Covid infection. The only means of prevention or control of this infection’s spread is by reducing the chances of getting infected through diligent use of what is popularly known as SMSSoap, Mask and Social distancing. The other main effort to prevent severe Covid and deadly diseases like mucormycosis should be in keeping the glycated hemoglobin (Hba1c) of everyone with diabetes under 7%. This is the most important step to ensure that the coronavirus does not become a life-threatening one.

An HbA1c below 7% makes one’s immunity and overall health almost equal to someone who does not have diabetes. So measure your HbA1c and follow all these measures to keep it under control: healthy diet, adequate exercises, regularity in medicines and frequent testing of blood glucose levels.

Why is HbA1c considered a more reliable test for diabetes than just random blood sugar checked with a glucometer?

Random blood sugar is a blood test that is taken to check the level of sugar in your body at any particular point in time. It is like a photograph taken at a particular point in time capturing the scene at the moment. However, blood glucose is one of the parameters that fluctuate a lot. It goes down before food and rises after food. Sometimes it may rise even in the early morning because the liver produces excessive glucose at night. It is thus difficult to keep track of one’s sugars throughout the day, week, or months. HbA1c is an indicator of the average blood glucose control achieved in 3 months. HbA1C Test in Chennai, IndiaSince this measures the percentage of sugar hemoglobin (hence the term “glycated” hemoglobin) inside the red blood cells which has a life of 3 months (approximately 117 days in men and 106 days in women), this measurement, taken once in 3 months, can clearly show one’s overall sugar control over a 2-3 month period. This is like getting a movie or a video of one’s sugar levels rather than a photograph. Glycated hemoglobin (HbA1c) was first published by Rahbar et al. in 1969. Subsequent research showed that the level of HbA1c depicted the glycemic control over a period of 2 to 3 months. This lead to the inclusion of HbA1c test into routine diabetes treatment in the 1980s. HbA1c levels also correlated well to the development of diabetes complications. HbA1c estimation thus has become a cornerstone of diabetes management.

However, the HbA1c test may be affected by several conditions as shown below :

Conditions that may cause abnormal HbA1c :

HbA1C Test for diabetes

Drugs that may cause abnormal HbA1c:

Drugs that may cause abnormal HbA1c:

What is Continuous Glucose Monitoring (CGM) and what is its role in this Covid season for patients with Diabetes


Continuous glucose monitoring
Continuous glucose monitoring

Continuous glucose monitoring (CGM) is possible when the patch the size of a two rupee coin is worn on the arm as shown in the picture, a reader (size of a pager) can help to continuously monitor the glucose levels without pricking repeatedly. This CGM is a boon to patients with diabetes, more so during covid. This is because the three-month blood glucose average or maybe hampered during or after COVID treatment due to the drugs given and the infection itself. After recovery from Covid, glucose control plays a pivotal role in gaining back health and vigor.

This simple and cost-effective device is worn on the arm for a period of 14- 15 days. This device can keep measuring the blood glucose about 100 times in 24 hrs and it displays the results as a graph – tabulating almost 1400 test results over a 14 day period. This will also give in a day, the percentage of time sugars were within the prescribed “normal” limits. This is called Time in range or TIR. This can link the glycemic control, the effect of medicines, diet and exercise.

 CGM Graph Report showing Time in Range, Time above Target
CGM Graph Report showing Time in Range, Time above Target

Also, this helps the diabetologist and the patient to see if there are unexplained low or high sugar readings during the day or night. Since night time low sugars can go undetected and can be life-threatening.

Checking one’s HbA1c and Time in Range during this season is much advised

  1. In order to keep blood sugar under control and to help prevent severe covid-19 or any other adjoining infections like mucormycosis etc
  2. To help a patient who has recovered from covid-19 regain their strength


  1. Unnikrishnan R, Anjana RM, Mohan V. Drugs affecting HbA1c levels. Indian J Endocrinol Metab. 2012;16(4):528-531. doi:10.4103/2230-8210.98004

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In order to facilitate blood sugar testing among the public, we are offering free random blood sugar tests using a glucometer to all those who walk into our clinics, along with FREE diet counseling during this #diabetescontrolmonth. Those with diabetes may check if they are in control. Those who have been affected by covid or have been administered steroids and recovered may also check if their blood sugars have reached back to their normal levels. Because #bloodglucose one parameter that can affect one’s health and well-being greatly. Uncontrolled diabetes is one of the main reasons for serious complications pertaining to #Covid like #mucormycosis (#blackfungus). For appointments call 8939110000 or email

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