Diabetes is probably as old as mankind. Great physicians during olden times had knowledge about this disease. Way back around the 6th century, Indian doctor Sushurata had done enormous work on diabetes.

He labelled it as ‘madhumeha’ meaning ‘honey in rain’, as the urine of patients attracted ants. Much research and development has taken place in the field of diabetes since then. Classification of diabetes and values of normal blood glucose have also been changing over a period of time for the better life of the diabetic.

Even though a lot of publications, journals and articles have been published regarding diabetes, people are still in a dilemma about the correct blood glucose values of a normal person and a diabetic person.

For a normal healthy individual, fasting blood glucose (FBS) can be around 70-110mg/dl and after one and half hour of eating postprandial blood glucose (PPBS) can vary between 100-140mg/dl. Normally, the normal values will be specified in the diagnostic laboratories.

Many individuals presume they have diabetes if their blood glucose values vary above this normal value. On the contrary, even if a person’s fasting blood glucose is around 110-125mg/dl and postprandial blood glucose is around 140-200mg/dl, he need not have diabetes. He will fall under the category of IGT or Impaired Glucose Tolerance.

The term IGT was coined way back in the year 1977. IGT is the predecessor of a diabetic condition. It may be called the younger brother of diabetes or "prediabetic state". People in this state usually do not require medication for diabetes but on the contemporary, associated factors like obesity, high cholesterol present in them, should be treated.

Types of IGT

*Progressive: where it progresses to diabetes sooner or later.
*Stationary: where it will be stagnant for many years.
*Regressive: where it returns to the normal range.

Diagnosis

Diagnosis of diabetes or IGT is made through oral glucose tolerance test (OGTT). Here, the patient is asked to take his normal food for three days and to report to the lab in the morning having fasted for at least 10 hours. A fasting blood sample will be taken, and the patient is given 75g of glucose dissolved in 250ml of water.

Blood is drawn every half hour at least four times. At the end, if the patient's second hour reading is more than 200mg/dl, then the patient is diagnosed to be diabetic. If blood sugar value is between 140-20mg/dl, then he will be in the ‘prediabetes state’ or IGT.

Less than 140mg/dl is supposed to be normal. Likewise, if fasting blood glucose values is more than 126mg/dl the patient is recognised to be diabetic, if it is 110-125mg/dl, the person is said to have ‘impaired fasting glucose tolerance’ or IFT while less than 110mg/dl is supposed to be normal. On the whole, the person’s blood glucose value, if found between 140-200mg/dl in the postprandial state need not consider himself to be diabetic. A good diet, exercise, reducing excess weight, avoiding fatty foods and living a stress free life will help him lead a normal life for a good number of years.