Indmedica - India's Premier Medical Portal - Cyber Lectures


Diabetes Mellitus - A Clinical Biochemist's View

Dr. Seema Garg M.D. (Biochemistry) Medical Officer

Page 2


A question which must have cropped up in the mind of many readers by now is I am healthy, should I get myself investigated for DM? Well friends, here is the answer to your query.

You need to get tested if you are 45 years of age or above, particularly if your Body mass index( BMI )is 25 or above. Also, if your results are normal now, you can be at ease for the next 3 years as that is the time you will need to repeat it, every 3 years till it continues to be normal.

Ideal body weight is: [(Height in cm’s) – 100] x 0.9 cm’s

(Height in meters) squared

If you are not yet 45 years of age , the recommendation for you is that you should go in for testing if you are overweight i.e. your BMI is 25 or more, and you have an additional risk factor or more – like a first degree relative with DM, are habitually physically inactive, are from a high risk ethnic group, have delivered a baby over 9 pounds, have high blood pressure, have HDL cholesterol of 35mg/dl or less , have triglyceride level of 250mg/dl or above, have polycystic ovary disease, or on a previous testing had IFG or IGT, or have a history of vascular disease.

Although the OGTT and FPG are both suitable tests, in clinical settings, FPG is recommended more because it is easier to perform, faster test, more convenient and acceptable to patients, more reproducible and less expensive. This approach grossly under diagnoses this global problem as there are a lot of people who will have a normal FPG , but will have an elevated 2-hour PG ,which may be in the impaired zone or in the overt diabetic range. It has now been hypothesized that the first abnormality that occurs is the rise in post-prandial (after meals) blood glucose. Fasting levels rise to abnormal values much later, even many years later, as insulin sensitivity worsens and insulin deficiency starts appearing. Hence the more meticulous physician will advise you to go in for both a fasting and a post glucose load blood glucose estimation to be on the safer side. This is actually very much in the interest of the patient, although it may appear cumbersome to many individuals, because the vascular damage will occur if high circulating glucose levels persist for a longer time. More so, more than half the patients would already be having complications as a result of vascular damage at the time they are diagnosed as having DM using the FPG approach. Actually, the primary aim in the management of diabetes is early detection and intervention. Early detection can be done by testing for plasma glucose at the time of the occurrence of an early abnormality in glucose metabolism. If we continue to screen the population with only FPG levels, many persons who have glucose intolerance would not be identified and this would expose their system to abnormally high levels of glucose for many years, and result in tissue damage. Testing blood glucose after a glucose load will help to identify patients at risk of developing diabetes in the future, as we shall be able to pick up those with impaired glucose tolerance as well, who are likely to get converted to overt DM later on. There are few persons in the the early stage of the disorder, who will show an abnormality in both test results— fasting and post-load glucose estimation, hence it is best to have both tested if one has to be doubly sure and one can afford it in terms of time and money.

At this juncture, it seems appropriate to talk about the much- practiced test of urinary sugar. This test is advocated by general practitioners to get an overview of the glucose metabolism in an individual. There is as such nothing wrong with this test, if used judiciously. High degree of dependency on this test is often misleading as there are numerous persons with no sugar in their urine, but very high blood sugar levels. This test may at best be used in conjunction with blood glucose estimation, to avoid missing an important diagnosis.

To monitor diabetes is a very meticulous affair, more so, with rising number of diabetics and the associated rise in complications as well. Most often, a newly detected diabetic is not one whose disease is of recent origin, it is just that it has been detected recently. There is an analysis termed the glycosylated haemoglobin, that tells about the glycaemic(glucose metabolism) status of the individual in the past three months or so. Normally it’s levels should be < 7 , but if the blood glucose has remained elevated in the past few months( approx. 8-12 weeks), then its levels are bound to be higher in the range of 12-25. Estimation of lipid profile is very essential in these patients. After starting medication, it is advised that the patient gets a follow up after 3 weeks with a fasting and post- glucose load blood glucose estimation. A glucometer for repeated testing at home is highly being recommended these days. A less popular test is that for glycosylated albumin, which detects the glucose status in the past few days as against few months previous status depicted by glycosylated haemoglobin. Limitation is that this test is not freely available for routine use.

1 2 3 Previous page Next page Back