Diabetes Mellitus: 6 Steps to Accurate Diagnosis

Diagnosis of diabetes mellitus requires that certain tests be carried out on the patient before you can conclude whether or not he/she has the problem. The steps to take to get an accurate diagnosis include:
History: The personal history from the patient coupled with physical examination and the classical signs of diabetes – polyuria (glucose in urine), polydipsia (abnormal thirst) and polyphalgia (excessive hunger) are often diagnostic. However, for the purpose of confirming the diagnosis, some laboratory tests have to be conducted, and they include:
Fasting Blood Glucose: The normal fasting blood glucose level in an adult without diabetes is 70-110mg/dl (4.5-5.6mmol/l). With diabetes mellitus this value becomes higher. Before the test is carried out the individual abstains from food for at least 8 hours. The individual is only allowed to take water, but other things capable of stimulating metabolism e.g. cigarette, tea, coffee, etc. should be avoided. Value above 110mg/dl is indicative of diabetes.
Post-Prandial Blood Glucose: An oral glucose load is administered to the patient and the serum glucose level is checked after 2 hours. In normal adult, serum glucose is expected to be less than 140mg/dl 2hours after ingesting the meal. But in diabetes mellitus the level returns to normal very slowly. If the value is above 180mg/dl after 2hours, this signifies that the individual is diabetic.
Glucose Tolerance Test: Prior to the test the patient is given a high carbohydrate meal of 150g for 3 days. Specimen of blood and urine are then collected at intervals of 1, 2, and 3hours and their sugar levels evaluated. A high level usually indicates the presence of diabetes. The nurse or the lab technician should however be sure that the patient is not having any physical illness, emotional stress or physical stress as these may interfere with the result since hormones secreted under these conditions influence blood sugar levels. All drugs that can influence blood glucose tolerance (oestrogen, steroids, salicylates, diuretics, etc.) should be stopped at least 3 days prior to the test. The test should be carried out in the morning because glucose tolerance decreases later in the noon. Specimen should as well be collected to serve as control.
Intravenous and Oral Tolbutamide Response Test: Tolbutamide stimulates endogenous secretion of insulin and indicates the pancreatic function; hence it is used as a confirmatory test for suspected diabetes mellitus. The patient abstains from food the night before the test. In the morning following the fast, a baseline fasting blood sugar is then taken. Tolbutamide is thereafter given to him and the blood specimens are taken 20 and 30 minutes after. The result shows a slower rate of decrease of blood glucose in the diabetic.
Urinalysis: Urinalysis may also be done to have an idea of the sugar level in the urine. Though this test is not diagnostic, it serves as a guide. The urine should be tested for the presence of glucose, albumin, white blood cells, casts and organisms to rule out glomerulosclerosis and urinary tract infection.