Screening for diabetes - is usually done to detect cases of type 2 diabetes, which make up for 90-95% cases of diabetes. Screening is not recommended for type 1 diabetes in the general population since it would probably detect very few cases.
Screening for Pre-diabetes - Screening also helps to detect pre- diabetes. Pre-diabetes is a condition where the blood sugar or hemoglobin A1c levels are above normal but have not reached the diabetic range. These patients could suffer from diabetes and heart disease in the future. Early detection helps them to control their diet and increase physical activity at the right time and thus prevent diabetes from setting in early.
Diabetes Screening Tests1. When should a person start screening for diabetes?
Screening for diabetes should start once a person is 45 years of age. It should be started earlier if he/she is overweight with a BMI of more than 25 km/m2 and has one additional risk factor for developing diabetes. These risk factors include:
► History of diabetes in parent or sibling
► Obesity with a BMI of more than 25 km/m2
► Physical inactivity
► Belonging to races like African American, Latino, Native American, Asian American or Pacific Islander
► Previously identified impaired fasting blood glucose or glucose tolerance test
► History of diabetes in pregnancy or delivery of a big baby
► High blood pressure
► High triglyceride and/or low HDL-cholesterol levels
► Conditions associated with insulin resistance like polycystic ovary syndrome or acanthosis nigricans
► History of disease affecting blood vessels
2. How frequently should tests for screening diabetes be carried out?
Screening tests for diabetes should be done every three years.
3. What are the tests used in screening for diabetes?
The following tests are used to screen for diabetes:
► Fasting plasma glucose levels (FPG)
A Fast Planning Glucose of 100-125 mg/dl indicates pre-diabetes and a level of more than 125 mg/dl indicates diabetes.
► Glucose tolerance tests (GTT)
In a glucose tolerance test, blood glucose levels are measured at the fasting state and 1 and 2 hours after an intake of 75gm of glucose. A blood level of 140-199 mg/dl at 2 hours indicates pre-diabetes whereas a level of more than 150 mg/dl indicates diabetes.
► Hemoglobin A1c level
Hemoglobin A1c testing measures average blood glucose levels for a period of up to 3 months prior to the test. An A1c level of 5.7% to 6.4% indicates pre-diabetes, whereas a level of 6.5% or higher indicates diabetes.
If any of the above tests are abnormal, the diagnosis of diabetes should be confirmed by performing at least one further test on a later day.
Frequently Asked Questions
1) Which doctor should I see for screening diabetes?
You may consult your general physician for diabetes screening. He will guide you to a laboratory to get the test done and a diabetologist/endocrinologist if the test is abnormal.
2) Will I have to take lifelong medications once I am diagnosed?
Your doctor may put you on a diet and advise increased physical activity if your sugar is not too high. Once you start the medication, you will probably have to take them lifelong depending on the blood sugar control.
3) Which test is used to screen patients for gestational diabetes?
Glucose tolerance test at 24 to 28 weeks is usually used to screen patients for gestational diabetes.
4) Does hemoglobin A1c test require fasting?
No. You do not need to be fasting for the hemoglobin A1c test.
Help in Early identification of Diabetic Retinopathy
References:1) Harrison’s Principles of Internal Medicine
Latest Publications and Research on Diabetes ScreeningLADA: a type of diabetes in its own right? - Published by PubMed
Treatment of Latent Autoimmune Diabetes in Adults: What Is Best? - Published by PubMed
Lower alpha fetoprotein and higher risk of hepatocellular carcinoma, study from the type 2 diabetes mellitus patients. - Published by PubMed
Type 2 diabetes and influence of diabetes-specific distress on depression. - Published by PubMed
A form of autoimmune diabetes in adults named LADA - an update on essential features and controversies. - Published by PubMed