Definition: GTT mean Glucose tolerence test.It is a laboratory test to diagnose diabetic mellitus.
- Mild DM.
- Almentary glycosuria.
- History of still birth,Spontaneous abortion.
- Premature labor,large baby.
- Hydramnios,toxaemia of pregnancy.
- To find out the ability of the body to carbohydrate metabolism.
- To detect:DM,Endocrine dysfunction,Renal glycosuria.
- Individual should be kept fasting for whole night(10-16 hours).
- Fasting venous blood for plasma and urine samples are collected.
- 75gm glucose in 250-300ml water is given by mouth.
- Venous blood and urine sample are collected either at the end of 2 hours or at half hourly intervals for 2-2.5 hours.
- Plasma glucose on each sample is estimated.Sugar or each urine sample is examined.
- Normal:Plasma/serum glucose value in all samples are with in normal range there is no sugar in urine.
|Fasting||Less than 5.5||7.8 or more|
|2 hours after 75gmglucose||Less than 7.8||11.1 or more|
- Impaired glucose tolerence: Intermediated between normal and Diabetes.
- Fasting glucose 5.5-7.8 mmol/L
- Post prandial glucose 7.8-11.1 mmol/L
- Renal glycosuria: Blood glucose values are normal but suger is present in urine due to renal threshold value for glucose.