Diabetes Flashcards
Diabetes Definition
- blood glucose that is inc. to the point that it would cause microvascular disease
- fasting glucose > 126
- 2 hr plasma glucose >200 during 75 g oral glucose tolerance test
- sx of diabetes with random plasma glucose >200
- A1C> 6.5%
A1C in Diabetes
- > 6.5% on 2 occasions is diagnostic
- represents avg blood sugar over last 3 months
- must be in absence of other medical illness
Fasting Glucose in Diabetes
->126 mg/dl
2 Hr Plasma Glucose in Diabetes
->200 mg/dl during 75g OGTT
Random Plasma Glucose in Diabetes
->200mg/dl with sx of diabetes
Impaired Glucose Tolerance/Impaired Fasting Glucose
- prediabetic
- inc. risk for macrovascular disease (CAD, CVD)
- 10% risk per year of progressing to T2DM
- impaired fasting glucose: 100-125
- impaired glucose tolerance: 140-199 during OGTT
- A1C: 5.7-6.4%
Sx of Diabetes
- polyuria
- polydipsia (excessive thirst)
- blurry vision
- weight loss
- sx present at ~90% loss of beta cell function in pancreas
Type 1 DM
- due to autoimmune destruction of beta cells in pancreas
- results in insulin deficiency
- occurs in childhood
- evidence of insulin deficiency: low C peptide
- low genetic contribution
- positive antibody blood tests
- normal weight
- predisposed to DKA
- insulin sensitive
- not related to vaccine exposure
Type 2 Diabetes
- most common form of diabetes
- insulin resistance
- more common in adults
- more common in hispanics, blacks, native americans, and pacific islanders
- overweight
- sedentary lifestyle
- strong genetic component
- DKA unlikely
- no beta cell autoimmunity but beta cells are dysfuctional (dec. insulin secretion)
Gestational Diabetes
- weight gain/pregnancy
- resolves after delivery
- inc. risk of T2DM in future
- risks: big baby, delivery complications, child at risk for T2 also
Pancreatic Diabetes
- insulin deficiency for beta cell destruction
- diarrhea and steatorrhea
- underweight
- lack glucagon in addition to insulin
- may occur in alcoholics
- prone to hypoglycemia
- inc. peripheral neuropathy
Stages of T1DM
- genetic predisposition
- overt immunologic abnormalities
- progressive loss of insulin release
- overt diabetes
- no C-peptide
4 Autoantigens Characteristic of T1DM
- insulin
- glutamic acid decarboylase 65 (GAD65)
- tyrosine phsophatase protein (IA2)
- zinc transporter (ZnT8)
- individuals with 2 or more autoantibodies will progress to T1D
- also genetic risk factors such as HLA DR3/4
Possible Environmental Factors of T1DM
- not vaccines
- viruses
- hygiene hypothesis
- diet (formula)
- obesity
C Peptide
-marker of endogenous insulin
Normal Plasma Glucose Values
-fasting
Diabetic Ketoacidosis
- severe hyperglycemia
- anion gap metabolic acidosis
- inc. ketones
- low insulin/glucagon ratio permits ketogenesis in the liver
- counter regulatory
- hormones are elevated
- most common precipitating cause is infection
- tx: volume replacement, insulin, potassium
Signs of Hypoglycemia
- adrenergic: sweating, tremor, tachycardia
- neuroglycopenic: confusion, convulsions, LOC
- pts can be unaware due to dec. adrenergic warning signs
Maturity Onset Diabetes of Young (MODY)
- autosomal dominant
- linked to mutaitons in glucokinase gene and mitochondrial genes
Macrovascular Disease Associated with DM
- MI
- stroke
- peripheral vascular disease
- lipid lowering significantly dec. mortality and CV events in pts with DM
- legacy effect: early blood sugar control in DM leads to dec. CV events 10-20 yrs later
Vascular Wall Response to Diabetes
- abnormal endothelial cell function
- abnormal vascular smooth muscle cell function
- inflammation and dec. fibrinolysis
Tx to Prevent Complications of DM
- B blockers
- antihypertensives
- lipid lowering agents
- ASA in high risk pts
Microvascular Disease Mechanisms in DM
- polyol pathway-> sorbitol, fructose
- non-enzymatic glycosylation-> AGEs
- elevation of protein kinase C
- oxidative/carbonyl stress
Microvascular Diseases Associated with DM
- retinopathy- hypoxic stress-> neovascularization
- nephropathy
- neuropathy-> ulceration