Glucose and Diabetes Flashcards
Fasting glucose serum/plasma reference range
3.3-6.0 mmol/L
Random glucose serum/plasma reference range
3.3-11.1 mmol/L
OGTT serum/plasma fasting reference range
2.2-6.0 mmol/L
OGTT serum/plasma 2hr reference range
</= 7.8 mmol/L
CSF glucose reference range
2.2-4.4 mmol/L
HbA1C reference range
4.3-6.1%
Lactic acid reference range
0.5-2.2 mmol/L
critical: >4.0 mmol/L
What is hypoglycemia
abnormally low blood glucose concentration
When is hypoglycemia most often seen
in patients with diabetes who are being treated with hypoglycemic drugs (insulin)
What is fasting hypoglycemia associated with
ethanol and salicylates
What is postprandial hypoglycemia associated with
insulin, antibodies to insulin or insulin receptors and inborn errors of metabolism
When is a hypoglycemia diagnosis made
when the criteria of the Whipple Triad is met
- symptoms are known or likely to be caused by hypoglycemia
- blood glucose is low when the symptoms occur
- symptoms are relieved by administration of glucose
What is hyperglycemia
abnormally high blood pressure caused by hormonal imbalance
What is diabetes mellitus
a group of disorders characterized by underutilization of glucose as an energy store causing hyperglycemia
What is type 1 diabetes mellitus
insulin-dependent diabetes
the insulin producing cells of the pancreas are destroyed by the hosts immune system, usually develops in children or teens
prone to ketosis
What is the treatment for type 1 diabetes mellitus
insulin and meal planning
islet cell, pancreas, kidney transplants
What is type 2 diabetes mellitus
the result of insulin resistance with or without defective secretion of insulin
normal levels of blood insulin are seen but the action of the insulin cells is defective, most common in adults
What is the treatment for type 2 diabetes mellitus
lifestyle modifications such as diet and exercise or medications such as insulin
What is gestational diabetes
a temporary condition characterized by glucose intolerance that begins or is first recognized during pregnancy
usually asymptomatic but is associated with increased morbidity and mortality as well as mother and child are at increased risk of developing diabetes
What is prediabetes
individuals at high risk of developing type 2 diabetes and its complications
usually have abnormal fasting glucose, OGTT or HbA1C results but do not meet the criteria for diagnosis yet
What is metabolic syndrome
individuals with type 2 diabetes and prediabetes can also present with additional symptoms of abdominal obesity, hypertension, dyslipidemia and elevated blood glucose
What are complications of diabetes
retinopathy, neuropathy, angiopathy, nephropathy, infection, dyslipidemia and atherosclerosis
When should patients start being screened for diabetes
around 40 years of age or older, every 3 years using fasting glucose or HbA1C
What is the diagnosis criteria for diabetes
fasting blood glucose >7.0 mmol/L, OGTT >/= 11.1 mmol/L or Hba1C >6.5%
What is the OGTT
a test to evaluate glucose clearance after loading with a defined dose under controlled conditions
What is the procedure of the OGTT
ingest a minimum of 150g carbs per day for three days leading up to the procedure
the patient then fasts for 10-16 hours
the test should be performed between 7 and 9 am
a fasting specimen is drawn and then the patient drinks a 75g glucose drink within 5 minutes a second draw is done after 2 hours
What are variables that affect the glucose tolerance
illness, oral contraceptives, thiazide, corticoid steroids, length of fast, age, activity, weight, smoking, caffeine, anxiety, stress, posture
What is the preferred specimen for blood glucose
serum or plasma
immediately separated
stable for 8 hours at RT
leukocyte and bacterial contamination can falsely decrease
24 hour urine samples should be collected in containers with 5mL glacial acetic acid
What is the hexokinase method of glucose testing used for
blood, urine and CSF
What are interferences in the hexokinase method of glucose testing
hemolysis, icterus and lipemia
What is the glucose oxidase method of glucose testing used for
blood and CSF
What are the interferences in the glucose oxidase method of glucose testing
hemoglobin, bilirubin, ascorbic acid and uric acid
When does glucose appear in the urine
when the blood levels exceed the renal threshold of 11.0 mmol/L
commonly associated with uncontrolled diabetes mellitus, advanced renal disease, pregnancy
When is a CSF glucose test done
to differentiate between viral and bacterial (low glucose) meningitis
What is hemoglobin A1C
a test that can be used to diagnose and monitor diabetes
HbA1C is proportional to the average plasma glucose concentration
it is reported as a percentage of the normal hemoglobin
in patients with unstable RBCs intra-individual results are compared rather than comparing to a reference range
What is fructosamine
non-enzymatic attachment of glucose to amino groups of proteins other than hemoglobin
fructosamine levels can be measured at 2-3 week intervals
individuals with kidney or licer disease have decreased serum protein therefore fructosamine cannot be used
How is fructosamine level determined
chromatography and photometric methods
What is the urine albumin:creatinine ratio used to monitor
kidney function of people with diabetes
screens for early kidney damage by detecting albumin in the urine
an ACR of >/= 3mg/mmol is clinically significant
Why do diabetics have increased ketones
a decreased use of carbs for energy causes the metabolization of fatty acids which produces ketones
What is B-Hydroxybutyrate used for
to determine if a patient is in metabolic acidosis
it can be detected by a colorimetric or gc-ms spectrophotometry
What is the reference range for B-Hydroxybutyrate
<0.4 mmol/L
What causes lactic acidosis
severe tissue hypoxia and association with disease (diabetes mellitus, liver disease, drugs and inborn errors of metabolism)
What is the reference range for lactic acid
0.5-2.2 mmol/L
critical: >4.0 mmol/L
