What is Diabetes Mellitus (DM)?
DM is a metabolic disorder due to a relative or absolute deficiency of Insulin.
What are the types of DM?
DM is broadly classified into type 1 and type 2 depending on its cause; in type 1 DM, the Islet cells in the pancreas, the source of Insulin is destroyed by the patient’s own defense mechanisms (immune system); in type 2 DM, there are defects in insulin secretion and action. Type 1 DM predominantly develops before the age of 30 and type 2 DM, after the age of 30 years. However, this is not a rule; type 1 DM may appear after 30 years of age and vice versa. Among these types, type 2 DM is more common worldwide.
How does Insulin act?
Insulin helps in uptake and utilization of glucose by the cells of the body. When it is deficient, glucose is not taken up by the cells of the body and we feel tired; glucose levels in the blood increases (hyperglycemia) and it overflows into the urine. Thus the body is deprived of an important source of energy.
How do you diagnose DM?
DM is diagnosed by any one of the following or if the below mentioned lab test abnormalities are confirmed on a repeat test:
- Symptoms of passing urine in large volumes, thirst, excessive hunger in association with random blood sugar >200mg/dL or
- Fasting blood sugar >126mg/dL or Two-hour blood sugar >200mg/dL following a glucose load or glycosylated hemoglobin (HbA1c ≥ 6.5%; see below for details)
What are the organs affected by DM?
Diabetes Mellitus causes disease of various organs by causing damage to small blood vessels (microvascular) or large blood vessels (macrovascular); microvascular damage affects retina, kidney, and nerves; macrovascular damage affects heart (heart attack), brain (stroke) and limbs (gangrene). It can also increase the risk of infections in these patients (especially a skin infection, urinary tract infection, and tuberculosis).
How do we detect the involvement of these organs by DM?
Patients with DM require periodic evaluation for retina, kidney and heart involvement and regular foot examination. Kidney checkup should include urine test for protein and serum test for creatinine; if protein is not detectable in urine on routine examination, small quantities of protein excretion can be detected by doing urine microalbumin. The check up should start five years from the beginning of type 1 DM and from the time of detection of type 2 DM. The frequency of checkup should be annual.
Why is it important to do regular check up for these complications?
Organ involvement in DM can be silent. Detection of organ involvement in early stages can help in prevention of severe complications. Once patients develop severe complications, they cannot be cured.
Is it possible to prevent these complications?
The single most important factor that helps in prevention of these complications is good control of DM. Apart from blood sugar control, cessation of smoking and control of blood pressure (if present) are other factors that minimize the risk of vascular complications of DM. Good fitting shoes, proper nail care and daily visual examination of the feet are important in preventing foot diseases in patients with DM.
What is "good control of DM"?
Good control of DM is indicated by HbA1c (see below) of less than 7% and preprandial (before food intake) and postprandial (after food) blood sugar values of 100-120mg/dL and 140-160mg/dL respectively.
What is HbA1c?
HbA1c, otherwise called glycosylated hemoglobin is a compound formed by the combination of glucose with hemoglobin. This biochemical reaction does not require enzyme. HbA1c is directly proportional to the peaks of sugar values over the previous two to three months. This time period is the turnover time of red blood cells (RBC) in human body; RBCs are the cells that have hemoglobin. While preprandial and postprandial values indicate current sugar ‘situation’ (status is not an appropriate word for this as sugar values are dynamic), HbA1c indicate control of DM over the previous two to three months.
Can we monitor glucose values?
Yes, it is possible to monitor our own glucose values using an instrument called glucometer and some strips. A prick is made on the finger (finger stick) for drawing a drop of blood. This drop is placed on the strip and then the strip is inserted into glucometer. We get a reading in a few seconds. This avoids frequent visits to the lab for sugar tests, helps in immediate decision making in sugar control and also for diagnosis of hypoglycemia (blood sugar values less than 50mg/dL in association with symptoms). Several brands of this instrument are available in the market. The approximate cost of this gadget is two thousand and the strip, thirty (both in Indian rupees). The requirement of strips may be around 30 to 90 per month depending on the existing control.
How can we achieve good control of DM?
Good control of DM can be achieved by a triad of treatment measures – diet control, physical activities and use of various medications. All these three are equally important in control of DM; one in the absence of other two will not help. Physical training helps not only to reduce and maintain weight but also improves the response of various body organs to insulin and conditioning of heart; therefore over a period of time, there is a possibility that the dose of antidiabetic medications can be lowered. It is not that the above three are required for a period of time and subsequently they can be stopped – they have to be continued indefinitely.
To achieve this goal, it is mandatory that the patient has good understanding about the illness and its complications. He should be educated about the need for regular visits, monitoring for control of DM and screening for complications and the role of physical training, diet and medications in improving the control.
What are the food stuffs that have to be restricted in DM?
Avoid foodstuff containing simple sugars (like sweets, sugar, glucose, honey, jaggery, jam, jellies, cakes, candies, dry fruits, soft drinks etc). Use unrefined cereal preparations. Do not sieve the cereal flours; include the husk into the daily diet. Consume high fiber diet as in vegetables and fruits. Eat them in the most natural form. Though restrictions on alcohol use areas for the general population, it should preferably be avoided as they provide empty calories and have no nutritional value. If consumed, it should be taken in moderation with food to minimize the risk of hypoglycemia. Avoid alcohol binges. Salads and clear vegetable soup can be taken liberally; coffee, tea, and milk can be taken without sugar (artificial sweeteners can be used in place of natural sugar).
Harrisons Principles of Internal Medicine 18th Edition