Carbohydrates Part 2 Flashcards
Symptoms unique to adolescent diabetes mellitus
They are the same as adults, but also:
- Blurred vision - frequent infections
- Slow wound healing - Hypertension
- Acanthosis nigricans (skin around neck or armpits appears dark, thick, and velvety)
Definition of double diabetes
Child has elements of both Type 1 and type 2 DM
How do patients develop double diabetes?
- Type one becomes overweight then becomes insulin resistant
- Type two developed antibodies to beta cells
What is the most important factor in the development of adolescent diabetes mellitus?
Important factor is weight gain in diabetic adolescents
Typical blood glucose levels and clinical findings in hypoglycemia
Symptoms: weakness, shakiness, sweating, nausea, rapid pulse, lightheadedness, epigastric discomfort
Severe Hypoglycemia
- cause
- typical blood glucose concentration
-Severe CNS dysfunction
Hypoglycemia in Neonates and Infants
- cause
- typical blood glucose concentration
- due to low glycogen stores at birth
- approximately 35 mg/dL
Fasting Hypoglycemia in Adults
- cause
- typical blood glucose concentration
- caused by certain drugs (most common), toxins, advanced liver disease, hormone deficiencies, insulinomas, septicemia, and end-stage renal failure
- < 45 mg/dl
Reactive Hypoglycemia
- cause
- typical blood glucose concentration
- Occurs in everyday life after eating
- < 45 - 50 mg/dl
Specific enzyme defect in galactosemia
galactase deficiency
Clinical symptoms and long-term effects of galactosemia
- infants who fail to thrive on cow’s milk; vomiting and diarrhea
- Later, can cause liver disease, cataracts, and mental retardation
Three lab means of galactosemia diagnosis
- screening urine for reducing substances via Benedict’s Test (Clinitest)
- ID of the sugar by paper
- Direct assay of enzyme activity
Specific enzyme deficiency of lactose intolerance
lactase deficiency
Clinical symptoms of lactose intolerance
- abdominal pain
- diarrhea
- lactose in urine
Specific cause of glycogen storage diseases
Caused by deficiencies of a specific enzyme in glycogen metabolism
What are the 3 liver forms of glycogen storage diseases?
What are their 4 general clinical biochemical features
Types I, IV, and VI
- are characterized by hepatomegaly,hypoglycemia, decreased insulin, and increased glucagon
What are the 4 muscle forms of glycogen storage disease?
What is one general clinical feature of the muscle forms of glycogen storage disease?
Types II, III, V, VII
- appear in young adulthood during strenuous exercise
specific enzyme deficiency in von Gierke’s disease
deficiency of glucose-6-phosphatase
Is von Gierke’s disease a liver or muscle form of a glycogen storage disease?
Liver form (most common and severe form)
Specific enzyme deficiency in Pompe’s disease?
Deficiency of alpha-1,4-glucosidase
Is Pompe’s disease a liver or muscle form of a glycogen storage disease?
muscle form
Why should separation from the cells or testing must be performed within a half hour of venipuncture in glucose testing?
Glucose decreases up to 7% per hour or more when serum is left in contact with cells
Why is oxalate-sodium fluoride the preferred anticoagulant in glucose testing?
(gray top) - it inhibits enolase, a critical enzyme in the glycolytic pathway
Whole blood glucose value
60-90 mg/dl
Plasma glucose value
70-100 mg/dl
Oxygenated, deoxygenated, and capillary blood glucose value
2 to 5 mg/dL higher than deoxygenated samples
What is the reason for the prompt analysis of CSF glucose?
due to possible cellular utilization and resultant false picture
What is the relationship normally observed between plasma glucose and CSF glucose?
CSF is lower than plasma glucose (60-70%) at the same time
Clinical significance for urine glucose
Glucose appears in urine after blood glucose exceededs renal threshold (160-180 mg/dL)
specific renal threshold range for urine glucose
160-180 mg/dlL
What are the 3 copper reductase methods for glucose?
- Benedict’s Test (Clinitest)
- Somogyi-Nelson
- Neocuproine Copper Reduction
Benedict’s copper reduction test (Clinitest)
- principle of measurement
based on the reduction of cupric iron in cupric sulfate. The change in absorbance is measured
Benedict’s copper reduction test (Clinitest)
- clinical significance of a positive test
Used as a screen for diseases of inborn errors of carbohydrate metabolism in newborns
Benedict’s copper reduction test (Clinitest)
- specific carbohydrates detected
galactose and glucose
Benedict’s copper reduction test (Clinitest)
- interferences
include false positives from other sugars, ascorbic acid, salicylates, penicillin, and uric acid
