• Glucose is the only sugar normally present in blood.• Sources:

From carbohydrate in diet.From liver glycogen by glycogenolysis.From glucogenic compounds by

gluconeogenesis.• Importance: Main energy source for brain Only energy source for exercising skeletal muscles and RBCs. Precursor of milk sugar (lactose), Ribose for nucleotides, CHO portion of glycoprotein.

• Insulin is the principle hormone affecting blood glucose level. • It's a small protein synthesized in β-cells of Langerhan's of pancreas.

Action: decrease BGL through: It promotes:- Glucose uptake by muscle and adipose tissue- Glycolysis and glycogenesis

• It’s antagonized by glucagon, epinephrine, glucocorticoid, thyroxin and growth hormones.

So BGL is a result of a balance between these endocrine forces.

Diabetes

• It’s a Greek term means large urine volume with 2 types: 

1.Diabetes insipidus, in which urine is tasteless.• Occurs due to deficiency of antidiuretic hormone (ADH).• Producing ployuria but without glucosuria.

2. Diabetes mellitus, in which urine taste sweet

Diabetes mellitus

Type 1: Insulin-dependent DM

(IDDM)

Type 2: Non insulin-dependent DM (NIDDM)

Common in childhood Common in adults > 35 yearsCharacterized by absolute lack of insulin due to β-cell destruction by antibodies or by viral infection.

Due to resistance of peripheral tissues to the action of insulin, so insulin level may be normal or even high.

Resistance occurs due to down-regulation or defect of insulin receptors.

Treated by insulin injection Treated by: diet control and exercise oral hypoglycemics

Symptoms:HyperglycemiaGlucosuriaPolyuriaPolydipsiaPolyphagiaWeight loss and weakness.

Chronic complication of diabetes:Cataract Retinopathy Nephropathy Neuropathy

Diagnosis:1. Random blood glucose (RBG):

• Normal RBG is 60-140 mg/dl.• RBG > 200 mg/dl on 2 different occasions indicates DM. 2. Fasting blood glucose (FBG):• Normal fasting blood glucose level is 70-100 mg/dl.• FBG > 120 mg/dl on 2 different occasions is diagnostic for DM.

3. Postprandial blood glucose:• Normally < 120 mg/dl.• Levels > 200 mg/dl on 2 different occasions is indicative of DM.

Diagnosis:4. Oral glucose tolerance test

(OGTT):

Long -term incidence of diabetes mellitus:

Glycosylated Hb

• It reflects BGL over 2 months prior to its measurement, the half-life of hemoglobin.• Used to monitor the therapy.

• Normal level: 4-8 %7% → indicates good diabetic control10% → indicates fair diabetic control13-20% → indicates poor diabetic control

Determination of Blood Glucose

• PRINCIPLE:Glucose Glucose oxidase H2O2 + Gluconic acid

2 H2O2 + Phenol + 4-amino-antipyrine Peroxidase

Coloured Quinonemine + 4 H2O

• PROCEDURE:1 ml Plasma Sample

+ 1 ml Working reagent

Mix, incubate for 20 minutes

Pink color(Measured at 510 nm)