OGTT

Objective of OGTT:

·        Assessment of endogenous insulin response to physiological glucose challenge.

Indication of OGTT:

·        Fasting blood glucose 6.1 – 6.9 mmol/L

·        Random blood glucose 7.8 – 11.0 mmol/L

Preparation for OGTT:

·        Unrestricted carbohydrate diet for 3 days before test.

·        Avoidance of drugs affecting blood eg; steroid, oral contraceptive.

·        Treatment of any infection.

·        Overnight fasting prior to the test.

·        Avoidance of smoking and exercise prior to test.

Procedure of OGTT:

·        Collection of fasting blood sample in the morning after previous overnight fasting and estimation of fasting blood glucose.

·        Intake of 75 g glucose orally with 300ml water within 5 min of fasting sample collection.

·        At the end of 2 hours of oral glucose intake another blood sample is collected for estimation of glucose.

Interpretation of blood glucose measured at 2hours after oral glucose load:

·        <7 .8mmol=".8mmol" :no=":no" dm="dm" span="span">

·        ≥11.1mmol/L : DM

·        7.8 – 11.ommol/L : IGT

·        <7 .8mmol=".8mmol" 6.1="6.1" 6.9mmol="6.9mmol" :=":" fbg="fbg" ifg="ifg" span="span" with="with">