Related News
Which is the most reliable diagnostic test for diabetes?
Question
Which test is more reliable among oral glucose tolerance test (OGTT) and routine blood glucose test to diagnose diabetes? I am a 46 years old woman having glucose levels of 98 mg/dl fasting and 140 mg/dl 2 hours after having a normal breakfast, in the routine blood glucose test. However, in the OGTT test, plasma glucose was 97 mg/dl fasting and 260 mg/dl 2 hours after having 100 g glucose water. What do these results indicate? Why is there a variation?
Expert Answer
S
Dr Sujeet JhaSep 16, 2008
Director,
Institute of Endocrinology, Diabetes & Metabolism,
Max Healthcare, New Delhi
Institute of Endocrinology, Diabetes & Metabolism,
Max Healthcare, New Delhi
The best way to test diabetes is by checking fasting glucose and 2 hours after taking 75 gram glucose, especially in a thin person. In obese middle aged individuals, fasting may be enough.
- Normal - Fasting plasma glucose (FPG) <100 mg/dL
- Two-hour glucose during OGTT <140 mg/dl (7.8 mmol/L).
- Pre diabetes (IFG and IGT)
- Impaired fasting glucose (IFG) - Fasting plasma glucose between 100 mg/dL and 125 mg/dL
- Impaired glucose tolerance (IGT) - Two-hour plasma glucose value during a 75 gram oral glucose tolerance test between 140 and 199 mg/dl
- Diabetes mellitus - FPG at or above 126 mg/dL, a two-hour value in an OGTT (2-h PG) at or above 200 mg/dL (11.1 mmol/L), or
- A random (or casual) plasma glucose concentration = 200 mg/dL in the presence of symptoms. The diagnosis of diabetes must be confirmed on a subsequent day by measuring any one of the three criteria.
Advertisement