How to Determine if Someone has Diabetes Mellitus

Laboratory Tests for diagnosing Diabetes Mellitus are Inexpensive & Easily Available

Diabetes Mellitus can exist in individuals with very few signs and symptoms. It is a chronic disease that may not manifest in a manner that will make life itself very difficult, until some the complications set in. However, these complications are very difficult to manage and virtually impossible to reverse. Thus, it is essential that diagnosis be achieved in time. Given the high frequency of Diabetes in modern societies, regular monitoring of blood sugar from time to time is advisable for everyone.

Diabetes Mellitus is a metabolic disease where the primary abnormality lies in the inability of the body to metabolise glucose in a manner that would not be detrimental to health. Rising sugar levels lead to passage of glucose in urine, while prolonged levels of high glucose can leave certain chemical markers that can possibly be detected by laboratory tests. These also mark the basic diagnostic tools for diagnosis and confirmation of Diabetes Mellitus in an individual.

Some of these tests can be easily carried out by the individuals at home or anywhere else with easy to carry kits.

Tests for Confirming Diabetes Mellitus

The diagnosis of Diabetes Mellitus depends primarily upon the rise of glucose in blood and its presence in urine.

Urine glucose (Urine sugar) test

Presence of glucose (or sugar) in urine is diagnostic of Diabetes Mellitus. Literally, the word Diabetes Mellitus means ‘sweet urine’ or ‘sugar in urine’. If glucose is identified in urine, it can be considered highly suggestive of Diabetes.  Yet, urine testing is not a confirmatory test, because of many different reasons. In particular, one needs to understand that a negative test or the absence of glucose in urine does not necessarily rule out Diabetes Mellitus. The reason for this is that kidneys begin to excrete glucose only beyond a particular level of glucose in blood, which is around 180 mg/dl and if the blood glucose level is lesser than that, glucose may not be detected in urine.

Blood Glucose Tests

Glucose is a substance normally present in blood. After taking food, its level rises and as time goes by, it falls back to fasting levels. In the normal body, the fine balance between Insulin and glucose ensures that blood glucose level remains with a certain range. In a Diabetic person, this balance is seriously disturbed leading to a higher fasting level, as well as higher levels after intake of glucose or foods like carbohydrates, which produce glucose on digestion. There is some difference in the criteria or cut-off levels used for diagnosis of Diabetes Mellitus. Most physicians tend to follow the criteria adopted by WHO in 2006.

Random Blood Glucose

A blood glucose test, done randomly, without any reference to food or fasting prior to the test is of considerably lesser value in diagnosing Diabetes Mellitus. However, if the blood glucose is over 200 mg/dl or 11.1 mmol/L, it suggests Diabetes.

Fasting Blood Glucose

A fasting blood glucose level, with no food for at least eight hours preceding the test, should be below 100 mg/dl or 5.9 mmol/L in a normal person. If this is above 126 mg/dl or 7.0 mmol/L, it is a sure sign of Diabetes Mellitus. A value that falls in between suggests an intermediary state, often referred to as Prediabetes or Impaired Glucose Tolerance.

Two Hour Glucose Tolerance Test

In this test, a sample of blood is taken for deriving fasting blood glucose level, followed by a specified amount of glucose given orally, and another blood sample taken after two hours to observe the blood glucose tolerance of the body. A value of less than 126 mg/dl or 7.0 mmol/L suggests a fully normal state, while a level of more than 200 mg/dl or 11.1 mmol/L is generally diagnostic of Diabetes Mellitus. A value that falls in between suggests an intermediary state, often referred to as Prediabetes or Impaired Glucose Tolerance.

To diagnose Diabetes, there should be two different confirmatory tests done on two different days, and both of them must be positive.

Glycosylated Hemoglobin or the Hb A1c test

The Hemoglobin A1c test provides an overview of the mean level of glucose in blood during the last 3 months preceding the test. It is more important in monitoring the level of blood glucose control, as a measure for deciding whether more stringent treatment is required. 

What to do if Your Tests are Neither Normal nor Suggesting Diabetes? 

As one can observe, there is a gap between normal and Diabetic blood glucose levels. These are considered cases of ‘Prediabetes’, which are sooner or later likely to develop fully blown up Diabetes Mellitus. Most such cases can be treated with weight loss, dietary modification, regular exercise and other lifestyle measures. Some of them may require small doses of oral hypoglycaemic medicines. Having an impaired blood glucose test is a warming that one needs to adopt a healthier life style, preferably under expert guidance, to prevent the onset of full blown Diabetes Mellitus. It also means that one needs to keep monitoring her Blood Glucose level regularly for the rest of one’s life.