Oral Glucose Tolerance Test (OGTT)

Slides:



Advertisements
Similar presentations
Endocrine Module 1b. Pancreas Gland 6 ” long Horizontal Behind stomach Upper left abdominal quadrant Both endocrine & exocrine functions.
Advertisements

Cerebrospinal Fluid (CSF) Analysis for total protein
Quantitation of Methemoglobin
MLAB 2401: Clinical Chemistry Keri Brophy-Martinez
Glucose Tolerance Test Diabetes Mellitus Dr. David Gee FCSN Nutrition Assessment Laboratory.
1 Role of the Laboratory in Differential Diagnosis of Diabetes Mellitus Dr. Essam H. Jiffri.
A medical test to determine the ability of an individual to maintain HOMEOSTASIS of Blood Glucose The most commonly performed version of the Test (OGTT)
DETERMINATION OF BLOOD GLUCOSE CONCENTRATION
Glucose test Ms. Ibtisam alaswad Ms. Nour A. taim.
BGM’s 1. Introduction  An estimated 135 million people worldwide — 18.2 million in the United States — have diabetes mellitus:  a disease in which the.
Oral Glucose Tolerance Test By: Dr. Beenish Zaki Date: 09/05/2012 Senior Instructor Department of Biochemistry.
Blood Glucose Test Dept.of Biochemistry. Determination of glucose concentration is important in the diagnosis and treatment of disorders of carbohydrate.
DIABETES MELLITUS DR. J. PRATHEEBA DEVI. Definition Definition Diabetes is a metabolic disorder characterized by raised levels of glucose in the blood.
Chapter 24 Chapter 24 Exercise Management.  Diabetes is a chronic metabolic disease characterized by an absolute or relative deficiency of insulin that.
DIABETES AND HYPOGLYCEMIA. What is Diabetes Mellitus? “STARVATION IN A SEA OF PLENTY”
Plasma Glucose. Glucose Glucose (MW: ) is a very important fuel source to generate universal energy molecules (ATP). Blood glucose regulation I-
Diagnosis of diabetes. Diabetic symptoms Diabetic symptoms + venous sample for : –Random venous ≥ 11.1 mmol/l ( ) –Fasting glucose > 7(
All body tissues can utilize glucose, the principle and almost exclusive carbohydrate circulating in blood. Glucose is a reducing monosaccharide that.
Estimation of blood glucose in diabetes mellitus.
EXPERIMENT SIX 1. Influence of Adrenalin and Insulin on Glucose Concentration in Serum 2. Determination of Glucose in Urine
DIABETES MELLITUS Current diagnostic criteria Diabetes symptoms (polyuria, polydipsia, unexplained weight loss) plus: – Random venous plasma glucose 200.
BCH302 [Practical] 1. There are three main methods of estimation the reducing sugar content in solution : 1. Reduction of cupric to cuprous salts. 2.
Glucose, quantitative determination
DIABETES MELLITUS IN CHILDREN. Blood glucose Apart from transient illness-induced or stress-induced hyperglycemia, a random whole-blood glucose.
Lab 4 M. Zaharna Clin. Chem. Lab.  All body tissues can utilize glucose, the principle and almost exclusive carbohydrate circulating in blood.  The.
BIOCHEMISTRY 285 PHL Introduction Blood Glucose. Blood Blood is vascular tissue that circulates in the closed system of blood vessels Functions: TransportationTransportation.
Chemical Examination of Urine Part II: Protein, Glucose Ricki Otten MT(ASCP)SC
Urinalysis By Elkhedir Elgorashi Elkhedir Elgorashi Lecturer Immunology M Sc, MLT, MT(MOH)
Practical Hematology Lab
Experiment 6 Measurement of blood glucose (GOD-POD method )
CHOLESTROL ESTIMATION DR. BEENISH ZAKI INSTRUCTOR DEPARTMENT OF BIOCHEMISTRY.
Triglyceride Estimation
Serum biochemical parameters glucose assay Biochemistry Clinical practice CLS 432 Dr. Samah Kotb Lecturer of Biochemistry 2015.
Clinical diagnostic biochemistry - 3 Dr. Maha Al-Sedik 2015 CLS 334.
Diabetes Mellitus Ch 13 ~ Endocrine System Med Term.
Diabetes Mellitus Introduction to Diabetes Epidemiology.
Diabetic Profile Measurement of Blood Glucose T.A. Bahiya Osrah.
Lecturer: Bahiya Osrah.  It is a chronic disease associated with hyperglycemia (increased blood glucose level) & glucourea (presence of glucose in urine)
Lecturer: Bahiya Osrah.  It is a chronic disease associated with hyperglycemia (increased blood glucose level) & glucourea (presence of glucose in urine)
Lab (7): Diabetic profile
Whole blood was the sample of choice for analysis However, values for glucose in whole blood are less than in plasma since red blood cells contain only.
Estimation of blood glucose in diabetes mellitus.
Determination Of Albumin In Serum By Bromocresol Green Method
Exp #1 Glucose Quantitative determination of glucose in serum or plasma.
Diabetes mellitus.
Medical Biochemistry Department
Triglyceride determination
بايو كمستري (م 3) / د . احمد الطويل
(Oral glucose tolerance test OGTT)
BLOOD OR PLASMA GLUCOSE
GLUCOSE TOLERANCE TEST (GTT)
Estimation of blood glucose in diabetes mellitus
D- Xylose Absorption Test
Oral glucose tolerance test (GTT)
Practical Analysis Using Spectrophotometer
BIOCHEMISTRY Blood Glucose
Practical Analysis Using Spectrophotometer
Cerebrospinal Fluid (CSF) Analysis for total protein
Blood Glucose Muthana A. Al-Shemeri.
Glucose test.
بسم الله الرحمن الرحيم 285 PHL Lab# 1 Introduction Blood.
Blood Glucose Test By Fifth Stage Student 18 Dr. Sakar Karem Abdulla
Glycated hemoglobin (HbA1c)
Blood Sugar Measurement
Glucose Tolerance Test Physiology lab-3 February, 2018
QUANTITATION OF METHEMOGLOBIN
Glycated hemoglobin (HbA1c)
Glucose test.
Urine Analysis Protein. Protein: Urine normally contains a scant amount of protein, which derives both blood and urinary tract itself. Proteins present.
Presentation transcript:

Oral Glucose Tolerance Test (OGTT) Biochemistry Practical 1- Batch 17

Glucose Tolerance Test Aim: To understand the significance of glucose tolerance test in clinical diagnosis Objectives: At the end of this practical you should be able to: Use the spectrophotometer to assay glucose in the plasma / serum. Interpret the results of glucose tolerance tests.

Instrument - SPECTROPHOTOMETER

Colorimeter / Spectrophotometer Colorimeter - Instrument to quantify the intensity of the color. Intensity of the color proportional to the amount of light absorbed and the concentration of the substance. Uses a std solution (known concentration).

THEORY Optical density (absorption) of the substance of a colored solution is directly proportional to the concentration of the substance.

Glucose tolerance test Definition - test done to assess the ability of the body to tolerate extra glucose taken orally hence known as oral glucose tolerance test (OGTT).

Procedure for GTT 1. Patient was asked to come after over night fasting. 2. Fasting blood sample (T0) collected. 3. Patient was given 75 g of glucose in 150ml of water orally and blood samples were collected at intervals of 1 hr (T1), 2 hr (T2) and 2½ (T2½) hr along with this urine sample was also collected. 4. Blood and urine samples were used for determination of glucose.

Steps involved in practical 1. Determination of Blood Glucose- Spectrophotometric method - Glucose Oxidase Method. 2. Determination of Urine sugar- Benedict’s method.

Principle - Blood glucose Glucose Oxidase- peroxidase-chromogen sequence (Glucose Oxidase Method) Glucose oxidase Glucose + O2 →→→→→ Gluconic Acid + H2O2 peroxidase 2H2O2 + phenol + 4-amino antipyrine →→→→→ quinoneimine + 4H2O quinoneimine measured at 505 nm.

Principle - Urine glucose Benedict’s Method Glucose + Benedict’s reagent Reddish brown precipitate Reduction

Materials provided Serum samples (X and Y) taken at intervals of 0, 1, 2 and 2½ hours. Urine samples (X and Y) and boiling tubes. 1.5 ml plastic cuvettes (for taking spectrophotometer readings). Spectrophotometer. Glucose oxidase reagent - Combined Enzyme-Color Reagent Solution.

Method Reagent Blank (B) (1 test tube) Standard (S) (1 test tube) Test (T) - T0,T1,T2, T2½ (4 test tubes) Dist. water 100 L (0.1 ml) --- Standard 100 mg/dL Plasma Glucose oxidase reagent 1 ml (1000 L) Incubation – 20 min room temperature, O.D reading – 505 nm

Calculation Concentration of glucose (mg/dl) = O.D reading of the test _________________ x Concentration O.D reading of the standard of std glucose Multiplied by 100 to express in mg/dl.

INDICATIONS FOR DOING GTT Fasting blood glucose is 110–125 mg% ORAL GLUCOSE TOLERANCE TEST (OGTT) Test done to assess the ability of the body to tolerate extra glucose taken. Preparation of the patient Patient should take adequate carbohydrate for at least 3 days before the test. The patient should fast the previous night (10–16 hrs.) Just before the test and while the test, the patient should refrain from exercise, eating, drinking, smoking, diuretics, oral hypoglycemic agents / insulin.

PROCEDURE FOR OGTT After overnight fast, venous blood sample is withdrawn for plasma glucose estimation. A urine specimen is also collected to test for the presence of glucose. The patient is administered 75 gms glucose in 300 ml of water, which the patient has to drink within 3-5 minutes. Blood and urine samples are collected for 2 hrs at 30 min interval, after the ingestion of glucose.

Benedict’s Test

INTERPRETATION OF RESULTS Normal Impaired Diabetes Glucose tolerance Fasting plasma Glucose (mg/dL) < 110 110-125  126 2 hrs after glucose load (mg/dL) < 140  140 but < 200  200

Features of a normal GTT curve: Benedict’s Test Features of a normal GTT curve: Fasting level within normal (70-110mg/dL). Peak value at 1 hour less than “Renal threshold value” (180mg/dL). After 2 hours comes back to fasting value. No sugar in the urine at any time.

Features of Impaired Glucose Tolerance: Impaired GTT Curve Fasting Benedict’s Test Features of Impaired Glucose Tolerance: 1. Fasting level above normal (115mg/dL). 2. Peak value at 1 hour more than renal thresh hold 190mg/dL. 3. After 2 hours does not come back to fasting value. 4. Sugar in the urine seen after the plasma value cross the renal thresh hold value. 5. Such patients may become diabetic after few years.

Renal Diabetes Patient GTT Curve Benedict’s Test Normal Blood glucose concentration, But excretion of Glucose in the Urine. Renal Diabetes Patient GTT Curve Benedict’s Test Features of Renal Glycosuria: 1. Fasting level within normal (70-110mg/dL) 2. Peak value at 1 hour less than “Renal threshold value”. 3. After 2 hours comes back to fasting value. 4. But sugar is seen in the urine

GLYCOSURIA In a normal person there is no sugar in the urine. If there is sugar in the urine it is a pathological condition.--- “GLYCOSURIA”. There are two types of glycosuria: 1. Hyperglycemic glycosuria. 2. Renal glycosuria (Renal Diabetes).

Hyperglycemic glycosuria: if the blood glucose level goes above the renal threshold which is 180mg/dL the glucose is seen in urine. In normal person the whole glucose reabsorbed in the renal tubules. Emotional glycosuria [Transient] -- stress, pain. Endocrine glycosuria ---Diabetes Mellitus, Hyperthyroidism, Cushing syndrome.

Renal glycosuria: The blood sugar levels are within normal limit, less than the renal thresh hold [180mg/dL] but still glucose is present in urine. Types: Hereditary renal glycosuria --- due to absence of Carrier protein. 2. Acquired renal glycosuria --- due to kidney problems and due to heavy metal poisoning. 3. Lowered renal threshold ---normal renal threshold is 180mg/dL.

Laboratory test to diagnose glycosuria: Benedict’s test: 0.5 ml urine + 5ml Benedicts test, boil and cool. Blue colour of Benedicts --- “NORMAL PERSON”. Green precipitate to red precipitate -- “GLYCOSURIA”.

Questions What is GTT? How is GTT done? What are the features of a normal GTT? What are the features of (a) Impaired glucose tolerance. 4. What is meant by glycosuria? What are the types of glycosuria? What is meant by polyuria? 7. What is the renal threshold value of glucose. 8. What are the causes of renal glycosuria.

GTT Procedure & Clinical application & Data interpretation. Normal value of Blood Glucose as per WHO criteria (Fasting & PP). Sodium Fluride Mode of action. Clinical significance of “Glycosylated hemoglobin” (HbA1c) & Fructosamine. Types of Diabetes: Type-1, Type-2, Juvenile DM, Renal Diabetes. Mode of action of Insulin & Glucagon. Insulin Resistance. Polyuria, melituria / glycosuria, proteinuria. Complications of uncontrolled DM: Neuropathy, Nephropathy & Retinopathy. Steate a few clinical conditions in which “hyperglycemia” can be observed. What is the “Renal Threshold Value” of glucose. What is “Advanced Glycation End Products (AGEPs)” and its clinical significance. Name a few oral hypoglycemic agents. Relevance of Metformin in G6PD deficiency.