Diabetes Mellitus Flashcards
Diagnosis of DM
FBS >/= 126mg/dl
RBS >/= 200mg/dl + symptoms
HbA1c >/= 6.5%
2hppg >/= 200mg/dl
Diagnosis of IFG or IGT
FBS 100-125mg/dl
RBS 140-199mg/dl
HbA1c 5.6-6.4%
2hppg 140-199mg/dl
Most reliable screening test for diagnosing DM
FBS and HbA1c
Marker of endogenous insulin secretion
C peptide
Key regulator of insulin secretion
Glucose > 70mg/dl
Rate limiting step in glycosis
Glucose phosphorylation by glucokinase
Most potent incretin
Glucagon-like peptide 1 (GLP-1)
Glucose transporter for glucose uptake in the muscle and fat
GLUT 4
Glucose transporter for glucose uptake into the beta cell of the pancreas
GLUT 2
Marker of autoimmune process of T1DM
Islet cell autoantibodies (ICAs)
Predominant mechanism in T2DM
Postreceptor defects in insulin-regulated phosphorylation/dephosphorylation
Two distinct syndromes of insulin resistance in T2DM
Type A: young, obesity, hyperandrogenism
Type B: middle-aged, hyperandrogenism, autoimmune disorders
Lab values of DKA
Glucose 250-600 mg/dl Hyponatremia Normal to increased potassium Normal chloride, phosphate, magnesium Slightly increased creatinine Osmolality 300-320 mOsm/ml High plasma ketones HAG metabolic acidosis pH 6.8-7.3, < 15 meq/l Respiratory alkalosis
Lab values of HHS
Glucose 600-1200 mg/dl Normal sodium, potassium, chloride, phosphate, magnesium Moderately increased creatinine Osmolality 330-380 mOsm/ml \+/- plasma ketones \+/- HAG metabolic acidosis Normal arterial pCO2
Pathophysiology of DKA
Insulin deficiency + Increased counterregulatory hormone excess (i.e. Glucagon)
Pathophysiology of HHS
Insulin deficiency + Inadequate fluid intake
More accurately reflect the true ketone body level
Beta hydroxybutyrate
Indication to start alkaline supplementation in DKA
pH = 7
Goal glucose in managing DKA to be able to stop insulin infusion
150-250 mg/dl
Major nonmetabolic complication of DKA therapy
Cerebral edema
Goal glucose in managing HHS to be able to stop insulin infusion
250-300 mg/dl
4 major theories explaining how hyperglycemia can lead to complications
- Advanced glycosylation end-products: protein and endothelial function
- Sorbitol pathway: REDOX and cell function
- Protein kinase C: enzyme function, gene expression, growth factors
- Increased fructose-6-phosphate in hexosamine pathway: growth factors, proteoglycan production
Primary causes of blindness in DM
Proliferative retinopathy and macular edema
Features of nonproliferative retinopathy
Cotton wool spots, microaneurysms, blot hemorrhages
