Carbs p.2 (Hyperglycemia and Hypoglycemia) Flashcards
Hyperglycemia Laboratory Findings
↑ 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 )
Hyperglycemia Diagnostic Criteria for Diabetes Mellitus
- Random plasma glucose
- Fasting plasma glucose
- 2-h plasma glucose
≥200mg/dL, + symptoms of diabetes
≥126 mg/dL
≥200 mg/dL during an OGTT
Categories of Fasting Plasma Glucose (FPG)
Provisional diabetes diagnosis
Impaired fasting glucose
Normal fasting glucose
FPG ≤126 mg/dL
FBG 100-125 mg/dL
FBG <100 mg/dL
Provisional diabetes diagnosis
Impaired Glucose Tolerance
Normal Glucose Tolerance
2-h PG ≤200 mg/dL
2-h PG 140-199 mg/dL
2-h PG <140 mg/dL
Causes of Hypoglycemia
a. Patients Appears Healthy
No coexisting disease -
Compensated coexistent -
b. Patients Appears ill -
A.
- Insulinoma, Islet hyperplasia
- Factitial hypoglycemia (insulin/sulfonylurea)
- Severe exercise, Ketotic hypoglycemia
-Drugs/disease
B.
-Drugs, Predisposing illness, Hospitalized patient
Genetic Defects in Carbohydrate Metabolism
Von Gierke Disease
(glucose-6-phosphatase deficiency type 1)
Galactosemia
(galactose-1-phosphate uridyl transferase dificiency)
Glycogen build up in the liver
due to inhibition of hepatic glycogenolysis
Von Gierke Disease
glucose-6-phosphatase deficiency type 1
Inhibition of glycogenolysis
Galactosemia
galactose-1-phosphate uridyl transferase dificiency
Diagnosis of Glucose Metabolic Alterations
Considerations:
- WB glucose concentration is 11% lower than plasma
- Serum / plasma must be refrigerated and separated from the cells within 1 hr
- Sodium flouride (gray-top) can be used to inhibit glycolytic enzymes
- FBG should be obtained in the morning after 8 to 10 hours fasting (not longer than 16 hours)
Diagnosis of Glucose Metabolic Alterations Methods:
- Fasting Blood Glucose
- POC
- 2-Hr Post Prandial Sugar
- OGTT
- HbA1C
Non Enzymatic Methods of Glucose Measurement
- Nelson Somogyi
- Hagedorn Jensen
- Ortho-toluidine (Dubowski)
Enzymatic Methods of Glucose Measurement
- Glucose oxidase (Saifer Gernstenfield)
- Hexokinase (Reference method)
- Clinitest
Copper reduction method (uses BaSO4 to remove saccharoids)
Glucose + arsenomolybdic acid arsenomolybdenum blue
Nelson Somogyi
Ferric reduction method (inverse colorimetry)
Glucose + Ferricyanide (yellow) Ferrocyanide (colorless)
Hagedorn Jensen
Condensation of carbohydrates with aromatic amines producing Schiff bases (green)
Ortho-toluidine (Dubowski)
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
Glucose oxidase (Saifer Gernstenfield)
Trinder’s reaction
a. False Low results
b. O2 Consumption electrode (polarographic glucose analyzers)
Glucose + ATP –hexokinase glucose 6-PO4 + ADP
Glucose 6-PO4 + NADP+ –G-6-PD NADPH + H+ + 6-phosphogluconate
Hexokinase (reference method)
a. ↑ in absorbance is measured at 340 nm
b. False low results due to gross hemolysis and ↑↑↑ bilirubin
Hexokinase (reference method)
A solution (75g of glucose) is administered and a specimen is drawn 2 hrs. later
2-Hour Postprandial Tests
FBS is taken. Glucose load is administered. Blood glucose is determined in 30 min, 1st , 2nd and 3rd hrs.
Oral Glucose Tolerance Test
HbA1C Measurement
Index for long term plasma glucose control __
Based on charged differences between___
Specimen requirement is ___ sample. N.V ___
(2-3 month period)
HbA1C and Non-HbA1C
EDTA WB
4.5 to 8.0%
Methods of HbA1C Measurement based on:
A. Structural differences
B. Charge differences
A. Structural differences
1. Immunoassays 2. Affinity Chromatography
B. Charge differences
- Cation-exchange Chromatography
- Electrophoresis
- Isoelectric focusing
- HPLC
