Carbs p.2 (Hyperglycemia and Hypoglycemia)

Question 1

Hyperglycemia Laboratory Findings

Answer 1

↑ glucose in plasma and urine
↑ urine specific gravity
↑ serum and urine osmolality
Ketones in serum and urine (ketonemia and ketonuria)
↓ blood and urine pH (acidosis)
Electrolyte imbalance (↓ Na,↑ K )

Question 2

Hyperglycemia Diagnostic Criteria for Diabetes Mellitus

1. Random plasma glucose
2. Fasting plasma glucose
3. 2-h plasma glucose

Answer 2

≥200mg/dL, + symptoms of diabetes

≥126 mg/dL

≥200 mg/dL during an OGTT

Question 3

Categories of Fasting Plasma Glucose (FPG)

Provisional diabetes diagnosis
Impaired fasting glucose
Normal fasting glucose

Answer 3

FPG ≤126 mg/dL
FBG 100-125 mg/dL
FBG <100 mg/dL

Question 4

Provisional diabetes diagnosis
Impaired Glucose Tolerance
Normal Glucose Tolerance

Answer 4

2-h PG ≤200 mg/dL
2-h PG 140-199 mg/dL
2-h PG <140 mg/dL

Question 5

Causes of Hypoglycemia
a. Patients Appears Healthy
No coexisting disease -

Compensated coexistent -

b. Patients Appears ill -

Answer 5

A.

• Insulinoma, Islet hyperplasia
• Factitial hypoglycemia (insulin/sulfonylurea)
• Severe exercise, Ketotic hypoglycemia

-Drugs/disease

B.
-Drugs, Predisposing illness, Hospitalized patient

Question 6

Genetic Defects in Carbohydrate Metabolism

Answer 6

Von Gierke Disease
(glucose-6-phosphatase deficiency type 1)

Galactosemia
(galactose-1-phosphate uridyl transferase dificiency)

Question 7

Glycogen build up in the liver

due to inhibition of hepatic glycogenolysis

Answer 7

Von Gierke Disease

glucose-6-phosphatase deficiency type 1

Question 8

Inhibition of glycogenolysis

Answer 8

Galactosemia

galactose-1-phosphate uridyl transferase dificiency

Question 9

Diagnosis of Glucose Metabolic Alterations

Considerations:

Answer 9

1. WB glucose concentration is 11% lower than plasma
2. Serum / plasma must be refrigerated and separated from the cells within 1 hr
3. Sodium flouride (gray-top) can be used to inhibit glycolytic enzymes
4. FBG should be obtained in the morning after 8 to 10 hours fasting (not longer than 16 hours)

Question 10

Diagnosis of Glucose Metabolic Alterations Methods:

Answer 10

1. Fasting Blood Glucose
2. POC
3. 2-Hr Post Prandial Sugar
4. OGTT
5. HbA1C

Question 11

Non Enzymatic Methods of Glucose Measurement

Answer 11

1. Nelson Somogyi
2. Hagedorn Jensen
3. Ortho-toluidine (Dubowski)

Question 12

Enzymatic Methods of Glucose Measurement

Answer 12

1. Glucose oxidase (Saifer Gernstenfield)
2. Hexokinase (Reference method)
3. Clinitest

Question 13

Copper reduction method (uses BaSO4 to remove saccharoids)

Glucose + arsenomolybdic acid  arsenomolybdenum blue

Answer 13

Nelson Somogyi

Question 14

Ferric reduction method (inverse colorimetry)

Glucose + Ferricyanide (yellow)  Ferrocyanide (colorless)

Answer 14

Hagedorn Jensen

Question 15

Condensation of carbohydrates with aromatic amines producing Schiff bases (green)

Answer 15

Ortho-toluidine (Dubowski)

Question 16

Β-D-glucose + O2 +H2O –glucose oxidase gluconic acid + H2O2

H2O2 + reduce chromogen –peroxidase oxidized chromogen + H2O

a. Couple reaction is known as
____ due to ↑ uric acid, bilirubin and ascorbic acid
b. _____ measure oxygen depletion

Answer 16

Glucose oxidase (Saifer Gernstenfield)

Trinder’s reaction

a. False Low results
b. O2 Consumption electrode (polarographic glucose analyzers)

Question 17

Glucose + ATP –hexokinase glucose 6-PO4 + ADP

Glucose 6-PO4 + NADP+ –G-6-PD NADPH + H+ + 6-phosphogluconate

Answer 17

Hexokinase (reference method)

Question 18

a. ↑ in absorbance is measured at 340 nm

b. False low results due to gross hemolysis and ↑↑↑ bilirubin

Answer 18

Hexokinase (reference method)

Question 19

A solution (75g of glucose) is administered and a specimen is drawn 2 hrs. later

Answer 19

2-Hour Postprandial Tests

Question 20

FBS is taken. Glucose load is administered. Blood glucose is determined in 30 min, 1st , 2nd and 3rd hrs.

Answer 20

Oral Glucose Tolerance Test

Question 21

HbA1C Measurement
Index for long term plasma glucose control __
Based on charged differences between___
Specimen requirement is ___ sample. N.V  ___

Answer 21

(2-3 month period)
HbA1C and Non-HbA1C
EDTA WB
4.5 to 8.0%

Question 22

Methods of HbA1C Measurement based on:
A. Structural differences
B. Charge differences

Answer 22

A. Structural differences

  1. Immunoassays
  2. Affinity Chromatography

B. Charge differences

1. Cation-exchange Chromatography
2. Electrophoresis
3. Isoelectric focusing
4. HPLC