Different Tests And Readings Of Blood Sugar You Need To Know

Diabetes mellitus (DM) is a disease with a characteristic of high blood sugar levels as the patient’s body fails to regulate it.

Diabetes has been diagnosed in at least 3.6 million Malaysians today. Diabetes used to be thought of as an elderly disease, although there is a significant increase in incidence among children and adolescents over years.

Diabetes has a strong relation to obesity and a poor lifestyle, personal habits, in addition to genetic factors. Thus, for anyone who wants to keep track of their own or their family member's blood sugar levels, here we will show you how to take a blood sugar reading and how to evaluate the readings. So, how would you know if you could have diabetes?

How Laboratory Tests Detect Diabetes

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1. Random Blood Sugar Level

The random blood sugar level test is used to measure blood sugar levels at random. That means that blood samples can be taken at any time and the influence of food is not taken into account.

The normal range for random blood sugar level is within 7.8 mmol/L to 11.1 mmol/L. The random blood sugar test results are not a test to diagnose diabetes, but for routine blood sugar monitoring at any time.

2. Fasting Blood Sugar Level (FBS)

The collection of blood samples for this test requires fasting of around 8 to 12 hours or over the night before the day of the test. Drinking water is allowed during the fasting period.

Under normal circumstances, the blood sugar levels will increase every time you fast; nevertheless, a healthy individual will be able to involuntarily utilize and balance out the overloaded blood sugar levels by using the hormone insulin.

Diabetic, on the other hand, will face the problems of utilizing their blood sugar levels and hence it remains high.

Fasting blood sugar levels of more than 7.0 mmol/L is one of the criteria for diagnosing diabetes. In addition, if a person has symptoms of diabetes, only a single reading excess of 7.0 mmol/L is considered sufficient to diagnose diabetes mellitus.

Meanwhile, for those without symptoms, the fasting blood test requires at least 2 readings more than 7.0 mmol/L for a doctor to confirm the diagnosis.

3. Oral glucose tolerance test (OGTT)

The OGTT is typically performed in less visible circumstances where it is uncertain if a person has diabetes or not. For example, an individual with fasting blood sugar levels within the normal range, but having the common symptoms of diabetes such as glycosuria, polyuria, and polydipsia.

The glucose tolerance test requires the candidate to consume his or her meals as usual for around 2 to 3 days, then fast for 8 to 12 hours over the night before the day of the test.

After these preparations, a fasting blood sample, FBS will be taken and a glucose drink that contains 75g of glucose solution will be given to drink immediately. Finally, the second blood sample, 1-HPP and a third blood sample, 2-HPP will be taken after 1 and 2 hours the candidate drank the glucose water.

The results of the glucose tolerance test are shown below.

How Laboratory Tests Monitor Diabetes

1. Glycated Haemoglobin (HbA1c)

This is the most effective and most widely used parameter to monitor diabetics. This test detects and measures the average blood sugar level over the previous three months. This test does not require fasting and blood samples can be taken at any time.

HbA1c is formed when haemoglobin, a protein in the red blood cells, is combined with glucose. The HbA1c works by moving glucose throughout the body as a source of energy. While excess HbA1c will combine with high amounts of glucose causing blood sugar levels to rise in diabetics.

Other than that, because the lifespan of red blood cells is at least 120 days, this allowed the HbA1c test can provide accurate blood glucose measurements for up to three or four months.

Individuals without diabetes had HbA1c levels of less than 5.6 percent and individuals with well-controlled diabetes should have HbA1c levels of less than 6.5 percent.

2. Urine Glucose Test

This test is to detect the presence of glucose in the urine, a common symptom of diabetes called glycosuria. This test usually uses a test strip that will change its colour after reacting with glucose in the urine. This test can also be performed at home using commercial test kits.

Normal individuals do not have glucose in their urine, while diabetics who have high blood glucose levels may have excess glucose filtered into the urine. Even so, pregnant women and those with impaired kidney function are likely to produce traces of glucose in their urine as well. These incidents make the urine glucose tests interpretation to be quite challenging. Therefore, this test is only used for monitoring diabetic patients and their kidney function.

Self-Monitoring Test Can Be Done At Home

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Blood sugar levels can be monitored at home easily using a machine or device known as the glucometer. This device can measure blood sugar levels by using blood samples taken from finger pricks. There are a few factors that may alter the accuracy of the results using this device, such as:

• Steps and technique of using the device

• The other blood contents like electrolytes, fat concentrations and some medications

• Anaemic patient

• Damaged or malfunction glucometer and measuring strip

• Different branded glucometer

That is why the diabetes readings obtained from the glucometer can only be used as a reference and for self-monitoring purposes. For accurate blood glucose levels, diabetic patients are still advised to undergo blood glucose tests from the laboratory on a regular basis.

Who Needs The Blood Glucose Tests?

Supposedly, all Malaysians should undergo a diabetes screening test. The reason being is that our daily lifestyle, diet, genetics and other factors do show that we are at high risk of getting diabetes mellitus. However, the MOH has decided and disseminated guidelines for the screening of diabetes.

1. Individuals With Signs and Symptoms of Diabetes

Examples of symptoms of diabetes are:

• Polyuria (frequent urination)

• Polydipsia (frequent thirst)

• Polyphagia (often feels hungry)

• Weakness

• Lethargy

• Weight loss

• Pruritus vulvae

• Balanitis

2. High-Risk Individuals Without Diabetes Symptoms

• Overweight or obese (BMI over 23 kg/m2 or waist circumference over 80 cm for women and 90 cm for men)

• First degree relatives with diabetes mellitus

• History of cardiovascular disease

• High blood pressure

• Hypercholesterolemia

• Glucose intolerance or an unsatisfactory fasting blood sugar test

• Women with polycystic ovary syndrome

• Other diseases associated with insulin deficiency such as endocrine diseases

• All pregnant women (the diabetes readings during pregnancy may be affected due to the influence of hormones produced.)

3. Individuals Without Risk Factors And Age of 30 Years and Above

If the screening test result is normal, the subsequent blood glucose test should be performed annually.

What Do Diabetics Should Be Aware Of?

​Diabetic needs to take care of their blood glucose level with caution, or else it may cause some medical emergencies. The incidences are very common if the blood sugar levels are not controlled appropriately, maintained in the normal range.

Hypoglycemia

Hypoglycemia is a condition in which plasma glucose levels are lower than 4.0mmol/L as well as the onset of autonomic or neuroglycopenic symptoms.

The individual will become drowsy, sweating, sense of hunger, thirst, shortness of breath, disorientation, loss of consciousness and more. If this happens, you can try eating some candy or drink sugary drinks.

Wait for 15 minutes and see if there is any sign of recovery. You may repeat these steps up to 2 times. If the symptoms and blood glucose level do not recover or have worsened, please immediately seek help from the hospital, emergency department.

Hyperglycemia

Hyperglycemia is a condition in which blood sugar levels increase drastically and develop certain signs and symptoms. For example:

• Diabetic ketoacidosis (DKA), happens when the capillary blood glucose levels exceed 11.1 mmol/L, capillary ketones exceed 3 mmol/L or urine ketones 2+, and venous pH is less than 7.3 or bicarbonate is lower than 15 mmol/L.

• Hyperglycemic hyperosmolar state (HHS), happens when the blood glucose levels exceed 30 mmol/L, hypovolemia and venous osmolality exceed 320 mosmol/kg.

Both of these hyperglycemic conditions as described above are very dangerous and potentially life-threatening. Therefore, if this happens, please immediately seek help from the hospital, emergency department for appropriate life-saving treatment.