GTT (Glucose tolerance test)

GTT (Glucose tolerance test)

Definition: GTT mean Glucose tolerence test.It is a laboratory test to diagnose diabetic mellitus.


  1. Mild DM.
  2. Almentary glycosuria.
  3. History of still birth,Spontaneous abortion.
  4. Premature labor,large baby.
  5. Hydramnios,toxaemia of pregnancy.


  1. To find out the ability of the body to carbohydrate metabolism.
  2. To detect:DM,Endocrine dysfunction,Renal glycosuria.


  1. Individual should be kept fasting for whole night(10-16 hours).
  2. Fasting venous blood for plasma and urine samples are collected.
  3. 75gm glucose in 250-300ml water is given by mouth.
  4. Venous blood and urine sample are collected either at the end of 2 hours or at half hourly intervals for 2-2.5 hours.
  5. Plasma glucose on each sample is estimated.Sugar or each urine sample is examined.


  1. Normal:Plasma/serum glucose value in all samples are with in normal range there is no sugar in urine.
  2. Diabetes:
Normal DM
Fasting Less than 5.5 7.8 or more
2 hours after 75gmglucose Less than 7.8 11.1 or more
  1. 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
  1. Renal glycosuria: Blood glucose values are normal but suger is present in urine due to renal threshold value for glucose.


Leave a Reply

Need help? e-Mail us here! Chat With Us Now!

← Prev Step

Thanks for contacting us. We'll get back to you as soon as we can.

Please provide a valid name, email, and question.

Powered by LivelyChat
Powered by LivelyChat Delete History