Chem: Section 3.3- Carbohydrate Metabolic Disorders

What are some common S/S of hypoglycemia? (at first and as it progresses)

heart palpitations, shakiness/dizziness, anxiety, sweating, hunger/tingling sensation in the mouth, irritability

As it progresses: confusion, indifference, abnormal behavior, inability to complete routine tasks, blurred or double vision, seizures and loss of consciousness (uncommon)

How do you diagnose hypoglycemia?

The common S/S alone are not specific to hypoglycemia, there may be other causes. A glucose level drawn at the time of the S/S is the only way to know for sure that hypoglycemia is the cause.

What are the glucose levels associated with hypoglycemia? At which levels are S/S observed?

diagnosed at

What is the difference between reactive and fasting hypoglycemia? What is the other term used for each?

Reactive, or *post-prandial* is caused by a stimulus or trigger.

Fasting, or *post-absorptive* is rare and occurs as a response to insulin-producing tumors (insulinomas)

How is reactive/post-prandial hypoglycemia diagnosed?

Whipple's triad

1) low blood glucose (

How is fasting/post-absorptive hypoglycemia diagnosed?

by testing C-reactive protein levels during a 72-hour fast

Where does glycogen accumulate in the body when there is a glycogen storage disease?

liver, skeletal muscle, cardiac muscle, adipose tissue

What is the pathology behind glycogen storage diseases?

missing or defective enzymes can cause *reduced amounts of glycogen* to be produced, *abnormal glycogen* to be produced, or glycogen *not being stored correctly*

What is the most common glycogen storage disease?

Type 1, Von Gierke's disease

What enzyme is deficient in Type I glycogen storage disease (Von Gierke's disease)?

glucose-6-phosphatase

What happens during Type I glycogen storage disease (Von Gierke's disease)?

Glycogen accumulates in the liver and skeletal muscle causing ineffective gluconeogenesis, hypoglycemia during fasting states, growth retardation, ketosis, lactic acidosis, and hepatomegaly

What is the primary enzyme linked to the inability to metabolize galactose normally?

Galactose-1-phosphate uridyltransferase

What are the S/S associated with galactose metabolism deficiency?

failure to thrive, liver problems, kidney problems, CNS problems, hypoglycemia

What is the cure for galactose metabolism deficiencies?

no cure, just remove lactose and galactose from their diet

What are the three enzymes that are linked to the inability to metabolize fructose normally?

fructokinase, fructose-1-phosphate aldolase, fructose-1,6-diphosphatase

What are the S/S of fructose metabolism deficiencies?

fructosuria is the only complication for the fructokinase enzyme deficiency. The others lead to ketosis, lactic acidosis, and liver failure

What is the hereditary pattern of fructose metabolism deficiency?

autosomal recessive

What is the treatment fructose metabolism deficiency?

no cure-- avoid eating fruits, honey, and corn syrup

How is lactate produced in the body?

Lactate is a by-product of the glucose metabolism pathway (lactate dehydrogenase enzyme)

lactate is produced from pyruvate in _________________ conditions

anaerobic

What are the enzymes involved in lactate testing? What is the final product measured?

Enzymes: lactate oxidase and peroxidase

Final product measured is a red colored dye at 540 nm which is proportional to the patients lactate levels

What is the preferred specimen for lactate testing?

venous plasma or venous arterial/whole blood. CSF can also be measured

What are some limitations to lactate testing?

don't create an anaerobic environment- no tourniquet, no exercise prior to draw, place sample in ice water

What are some potential consequences of lactate metabolism deficiency?

lactic acidosis, poor circulation and oxygen

What is the difference between diabetic ketoacidosis (DKA) and Hyperosmolar Hyperglycemia Syndrome (HHR) in terms of lab findings?

HHR: normal ketones, much higher glucose than DKA

DKA: high ketones in urine and blood, glucose not as high as HHR