How to confirm Diabetes? How to know if you have Diabetes? How to diagnose Diabetes Melliturs? Which tests to confirm Diabetes? Which tests should be undertaken for Diabetes?
Diabetes Mellitus is a condition that affects a large number of people around the world. Estimates suggest that more than 220 million people in the world are affected from it, and around 3.4 million people may be losing their life every year because of it. Ironically, a lot of people affected by it do not even know that they are suffering from such a condition, making Diabetes Mellitus the most dangerous silent killer of our times. Worst of all, the World Health Organisation projects that the number of people dying from Diabetes will double between 2005 and 2030, making it imperative that every person on this planet becomes aware about this condition.
What is Diabetes Mellitus
Diabetes Mellitus is a disease of glucose metabolism, resulting from inadequate or defective insulin, or defective response to it by the body. To understand Diabetes Mellitus, one needs to be aware of the normal glucose cycle in the body.
Our bodies need glucose as source of all energy. All forms of carbohydrates in food are digested in the intestines to produce glucose, which is then absorbed in blood and taken to different parts of the body. While some of it is immediately taken up by cells of the body and utilized there, the remainder is stored by liver and other parts for later needs, after conversion to another form called glycogen. This process of conversion of glucose to glycogen is facilitated by Insulin, a hormone produced by the Islet cells of Pancreas, and it is this effect of Insulin that regulates the level of glucose in blood. As soon as the blood glucose levels rise, Insulin is produced. This Insulin then stimulates the absorption of glucose and its conversion to glycogen, and prevents the blood glucose level from rising.
If there is insufficient production of Insulin or if the cells of the body do not properly respond to the Insulin that is produced, then, the body cells are unable to take up glucose from blood. As a result, all the glucose absorbed from the digested food in intestines keeps accumulating in blood, leading to a rise in blood glucose levels. When blood glucose exceeds a certain level, then glucose begins to get passed in urine, as kidneys are no longer able to hold it back. As a result, glucose is present in urine, and by its osmolar impact, it also drags a lot more water along with it, causing excessive urine formation or polyuria. This excessive loss of water leads to dehydration and thirst, so the affected person has a tendency to drink lots of water.
Diabetes Mellitus is a disease resulting from defective glucose metabolism. In this condition there is either a deficiency of insulin in the body, requiring Insulin injections (hence also known as Insulin dependent or Type I Diabetes Mellitus), or the body does not respond properly to insulin, a condition known as Insulin Resistance, requiring various measures to reduce the need for Insulin (hence also known as Non-Insulin dependent or Type II Diabetes Mellitus). Both the conditions are marked by a high glucose level in blood which may be associated with the presence of glucose in urine.
What are the signs & symptoms of Diabetes Mellitus
The common symptoms of Diabetes Mellitus are Polyuria (high frequency of urination), Polydipsia (high intake of water) and sometimes weight loss (especially in Type I Diabetes) in spite of a good appetite (known as Polyphagia).
These symptoms are far more commonly observed in cases of Type I Diabetes, which occurs in life earlier than Type II. Since type I affects within the first three decades of life, it is also termed as Juvenile Diabetes. In comparison, the Type II Diabetes usually occurs later in life, and is seldom marked by the classical symptoms of polyuria, polydipsia and polyphagia. People with Type II Diabetes may not observe any symptom for a long time, and it is not uncommon for them to discover their Diabetic status by accident during a routine test of blood or urine. Since, Type II Diabetes Mellitus accounts for almost 90% of Diabetes in the world, most affected persons may actually become aware of their symptoms, if any, only after they come to know that they have Diabetes.
Diabetes leads to a variety of acute and chronic complications, and sometimes the first symptoms that one observes may be related to them. The acute complications include Diabetic Ketoacidosis and Non Ketotic Hyperosmolar Coma, both life threatening conditions associated with deteriorating consciousness and finally coma. Chronic complications of Diabetes affect the kidney, eyes and nerves and may result in various symptoms related to them. Presence of Diabetes Mellitus also delays healing and recovery of infections. Hence, if a person has an ulcer that is not healing, or the infection is not subsiding in spite of heavy treatment with antibiotics, Diabetes must be ruled out before other measures are adopted.
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 within 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 110 mg/dl or 6.1 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 confirmative 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.