Glucose/Hgb A1c Flashcards
WHO Diabetes Statisitics
- > 220 million people worldwide
- 26 million in US
- 7 million (27%) unaware of condition
- $245 billion in US healthcare costs/year
Carbohydrates
- Major energy source
- Blood concentration maintained c various influences
- Lowered
- Insulin - lowers blood glucose by promoting cellular updatke and glycogen synthesis
- Raised - promote glycogenolysis
- Glucagon
- Cortisol
- Epinephrine
- Growth hormone
- Lowered
Diabetes Mellitus (DM)
Prolonged hyperglycemia due to one or both of the following:
- Insulin secretion defect
- Insulin action defect
Consiquences, untreated DM
(6)
- Retinopathy
- Vascular damage
- Renal failure
- Neropathy
- Cardiac disease
- CVA
Diabetes Classifications
(4)
- Type I
- Type II
- Gestational
- “Other” - group of varying dx
Type I DM Characteristics
(4)
- “Insulin dependent”
- 5-10% of cases
-
Abrupt onset of s/sx
- Polyuria
- Polydipsia
- Weight loss
- Insulinopenia - require insulin to sustain life
Type II DM Characteristics
(6)
- Non-insulin dependent
- ~90% cases
- Minimal s/sx - not prone to ketosis
- Insulin levels may be normal, decreased, or increased
- Impaired insulin action
- Obesity is common
Causes of Secondary DM
(5)
- Genetic defects in insulin secretion/action
- Pancreatic surgery/disease
- Endocrinopathies (Cushing’s, acromegaly)
- Drugs, steroids
- “Other syndromes”
Diagnostic Criteria, DM
(4 options)
Note - usually these tests are performed in progression
- S/Sx + casual/random plasma glu >200mg/dL
- Casual = any time of day s regard to time since last meal
- FPG (fasting for at least 8 hrs) >126 mg/dL on multiple occasions
- 2 h post glucose load >200 mg/dL during OGTT (Glucose Tolerence Test)
- Hemoglobin A1c >6.5%
“Increased Risk” For DM
(2)
Impaired glucose tolerence (IGT) - “Pre diabetes”
- Fasting plasma glu 100-125 mg/dL
- 2 hr OGTT 140-200 mg/DL
Fasting Glucose (FPG) Ranges
< 100 = normal
100-125 = “impaired”
>126 = provisional dx, DM
Oral Glucose Tolerance Test (OGTT) Values
< 140 2h post load = normal
140-199 post load = “impaired”
>200 = provisional dx, DM
Gestational DM
(def, explaination, incidence, prognosis)
Def: CHO intolerence onset during pregnancy
Explaination:
- demands of pregnancy exceeds mother’s capacity to secrete insulin
- fetus secretes more insulin
- stimulate fetal growth, macrosomia
Icidence: ~3%
Prognosis:
- usually asymptomatic and life threatening to mother but increases chances for DM II later
- asst c inc neonatal hypocalcemia, hypoglycemia, macrosomia
Gestational DM Screening
(4 step procedure)
Protocol:
- Initial glu test on at risk women
- Repeat 24-28 weeks
- If elevated, repeat c modified 1 hr OGTT
- If still elevated, perform 3 hr OGTT
Testing Type:
- Initially, no fasting
- If +, use 50 g oral loading dose and 1hr plasma glu
Diagnosis, Gestational DM
(4 qualifications)
- Fasting venous plasma > 92 mg/dL
- 1 hr venous plasma >180 mg/dL
- 2 hr venous plasma >153 mg/dL
- 3 hr venous plasma > 140 mg/dL
If 2 hr OGTT + one other value exceeds threshold, GDM present
Postpartum GDM
Since risk for Type II DM is high after developing GDM (30% within 5-10 years), women must undergo dx testing 6-12 weeks postpartum
Hypogycemia
Blood glucose below fasting average
Causes, Hypoglycemia in Diabetic Pts
(8)
- Oral hypoglycemic agents
- Insulinoma
- Islet hyperplasia
- Severe exercise
- Hypothyroidism
- Hypopituitarism
- Addison disease (cortisol deficiency)
- Liver disease
Causes, Hypoglycemia in Non-diabetic Pts
(2 categories, 5/2 specifics)
Fasting
- Insulin
- EtOH abuse
- Severe hepatic/renal insufficiency
- Hypopituitarism
- Surreptitiuos insulin injection
Postprandial (symptoms develop 1-2 hrs post meal)
- Ailmentary hypoglycemia
- Functional hypoglycemia - pt has not undergone GI surgery
Specimensd for Glucose Testing
(4)
- Blood glucose
- Serum
- Plasma (note - Na fluoride inhibits glycolysis)
- Urine
- CSF
- Whole blood
Draw blood in correct tube!
- Gray tube if blood sample will not be tested w/i 1 hr to prevent glycolysis inhibition
- Red top for blood sample that will be tested w/i 1 hr
Diabetes Analytes
(9)
- Glucose
- blood
- urine
- Glycates proteins
- Glycated hemoglobin - HbA1c
- Gycated albumin - fructosamine
- Ketones
- blood
- urine
- Urine protein
- urine albumin excretion
- Genetic markers
- Autoimmune markers (Ab)
- ICA
- IAA
- GAD
- IA-2
- Insulin + precursors
- Lipids
- “Others” - amylin, leptin, blood lactate, urinary albumin, fructosamine, ketone bodies, glucagon, Hgb A1c
Blood Lactate (Lactic Acid)
(endogenous fctn, elevation - 2 categories 4/3 specifics, sample handling)
Fctn: intermediate in CHO metabolism
Elevation:
- Hypoxia
- Shock
- Severe blood loss
- AMI and CHF
- Pulmonary edema
- Metabolic
- DM
- Liver/renal disease
- Toxins - ethanol, methanol, salicylate poison
Handling:
- Gray top tube
- Keep cold
Fructosamine
(endogenous fctn, clinical usefulness)
Endogenously: glycated serum PRO
Usefulness: monitor short-term glycemic changes (2-3 weeks)
Ketone Tests (2)
- Acetest (tablet)
- uses sodium nitroprusside
- detects acetoacetic acid and acetone
- does not detect beta-hydrobutyric acid (predominating ketone, requires a special test)
- Ketostix
