Diabetes Mellitus Flashcards
What is insulin and timeline of how it works?
controls blood glucose levels in the body
Once a meal is eaten, glucose enters the bloodstream which increases blood sugar concentration and insulin is released from pancreas
What does insulin do?
helps glucose go from the blood to cells or stops the liver from releasing glucose from storage and liver converts it to glycogen
once blood sugar levels are normal, insulin is blocked
What is diabetes mellitus
hyperglycemia (increased blood glucose) due to excessive glucose production or impaired glucose clearance
What are the types of DM
T1DM T2DM Gestational Diabetes LADA MODY
What are the different ways to test blood sugar levels?
Fasting Blood Glucose
Random Blood Glucose
HbA1c
OGTT (Oral Glucose Tolerance Test)
What are the blood glucose levels for FBG
Normal: 70-99mg/dl
Pre-DM: 100-125mg/dl
DM: >126mg/dl
What are the blood glucose levels for RBG
Normal: <140mg/dl
Pre-DM: 140-199mg/dl
DM: >200mg/dl
What are the blood glucose levels for HbA1c
Normal: <5.7%
Pre-DM: 5.7-6.4%
DM: >6.5%
What are the blood glucose levels for OGTT
Normal: <140mg/dl
Pre-DM: 140-199 mg/dl
DM: >200mg/dl
How does the HbA1c test work
A1c is the component of the hemoglobin that binds to glucose and so the more A1c = the more complications you have
It does an average reading over 2-3 months (life of a platelet)
At 6% = 125 mg/dl and every 1% increase is 30mg/dl
How does the OGTT test work?
Patient ingests 75-100g of glucose and we measure the 1,2,3 hour mark and see the chart
A diabetic will have a large spike and take more time to bring the levels down
What are the symptoms of DM
polyuria, polydipsia, polyphagia, blurred vision, weight loss, extreme fatigue, slow healing sores, frequent infection, and tingling/numb extremities
What is the epidemiology of DM
most common endocrine disorder in US (#7 in death)
incidence increases with age, obesity, sedentary lifestyle
US: Natives > AA > Hispanics > Asian > White
Leading cause of kidney failure, non-traumatic limb amputee, and blindness
Contributes to heart disease + stroke
What happens in pre-DM stage and its risk factors?
usually asymptomatic but body is developing insulin resistance and increased risk of CV pathology
50% within 10 years progress to T2DM
obesity, sedentary, 45+, family history, race, BMI >25, GDM, baby over 9 lbs, HTN, hyperlipidemia
What happens in T1DM
absolute deficit of insulin from pancreatic atrophy and loss of beta cells
5-10% cases usually diagnosed as kids where they lose function of pancreas
idiopathic or immune-mediated
M=F; older mothers, pre-eclampsia, and autoimmune disorders (hashimoto, graves, addison, pernicious anemia, MS)
How do you treat T1DM
Insulin injection or pump
What happens in T2DM
most common form (90-95%) where people have peripheral insulin resistance and insufficient insulin production
Polygenic disorder from sedentary lifestyle, obesity, family history, GDM, impaired glucose metabolism, Age, Race
Manifestations: CV damage, vision loss, neuropathy, recurrent infections, and renal failure
How do you treat T2DM
Diet, Exercise and Meds (oral + injection)
What is gestational DM
happens during pregnancy where you have glucose intolerance from estrogen and progesterone antagonizing insulin
2-10% pregnancies and usually temporary but can lead to T2DM (50%)
Risk Factors: AA, Hispanic, American Indian, Obesity and family history
How do you treat GDM
insulin or 2nd line (metformin and glyburide)
What is LADA
latent autoimmune diabetes of Adults (T1.5)
slow progression B-cell failure of pancreas
onset around 30 years old
Treated with insulin
What is MODY
Maturity Onset Diabetes of Young
Early T2DM - autosomal dominant
ineffective production of insulin
onset around late teens or early 20s
Treated with oral meds and maybe insulin
What is metabolic syndrome
a cluster of conditions that increase your risk for CHD, DM, and Stroke
FBG > 100 TG > 150 HDL < 40 BP > 135/85 Waistline: >40 and >35 Associated with sedentary life, obesity, insulin resistance, BUT preventable with diet, exercise, and meds
NEED MORE THAN 3**
What are the effects of chronic hyperglycemia
Glycation of Proteins (abnormal cross-linking)
- protein + glucose over time (becomes permanent) = AGE (cross-linking proteins)
Accumulation of Sorbitol (cellular edema bc it loves H20)
- elevated glucose gets converted to sorbitol (30%) in hyperglycemia vs normoglycemia (3%)
Increased activation of Protein Kinase C (increased DAG to increased PKC) DAG: diacyl glycerol
- vasoconstriction (impede blood flow)
- vascular permeability (angiogenesis)
- thicker BM (decrease O2 transmission)
- capillary or vascular occlusion
What are the macrovascular effects of hyperglycemia
Heart (CAD, MI, CHF), Cerebrovascular Disease (TIA, Stroke), Peripheral Artery Disease (Amputations)
What are the most common causes of death in T2DM
coronary artery disease + stroke
What are the microvascular effects of hyperglycemia
Retinopathy, Nephropathy, and Neuropathy
what is endothelial glycation (think abnormal cross linking, pericytes, and glycated RBC)
abnormal cross linking damages the endothelium and causes the basement membrane to thicken and decreases O2 transmission
the loss of pericytes over time lead to weak blood vessels and micro-aneurysms (leaks)
Glycated RBC or platelets stick to the vessel wall which becomes a thrombus and leads to obstruction or rupture and then exudate / hemorrhaging / ischemia
What is diabetic nephropathy
most common death in T1DM (AA, Asian, NA > White)
DM is leading cause of renal failure + ESRD due to glomerulosclerosis (scarring of renal tissue) leading to albuminuria
TX: hemodialysis + treat underlying conditions
Chronic hyperglycemia leads to kidney wanting to filter out the glucose but with time that causes problems and damages the glomeruli leading to decreased GFR and renal failure
What is diabetic neuropathy
demyelination of nerves throughout body and affects 60-70% of DM
caused by hyperglycemia, lack of insulin, ischemia, and duration / control of DM
What are the types of neuropathy
peripheral (most common) - sensory before motor
autonomic: bladder incontinence, impotence, diarrhea, and perspiration
Proximal: thighs, legs, hips
Focal: can affect ANY nerve in body (CN palsy)
What is diabetic retinopathy
1 cause of blindness in working population (20-65)
pericytes break down around the blood vessels and are part of the BBB so when they break down, retinal microvasculature becomes leaky
Dx > 10 years: 50% chance of retinopathy
Dx > 15 years: 90% chance of retinopathy
want the A1c to be less than 7%
How do cataracts form from DM
the accumulation of sorbitol makes the lens swell and lead to apoptosis and free radical formation
lenticular swelling + vacuole formation + lenticular opacification
a posterior subcapsular cataract can affect vision
What are some other ocular manifestations from DM
myopic shift, decrease in amp, early onset presbyopia, 2x risk of glaucoma, and decreased corneal sensitivity
What are the effects of acute hyperglycemia
hypoglycemia and DKA
What is DKA
diabetic ketoacidosis: when there is no insulin, glucagon is not suppressed and glycogen will be depleted and then the body will produce excess ketones (acidic) and make the blood acidic
Hyperglycemia + Hyperketosis + Acidosis (T1»T2)
TG > 200mg/dl + Ketones in blood/urine and a pH of <7.3
What are the symptoms of DKA
fruity breath from acetone, altered mental status, and hyperventilation because of the attempt to stabilize blood pH to decrease CO2
What is the treatment for DKA
normalize blood glucose levels or rapid insulin
What is hypoglycemia? T2 or T2? What are the BG levels?
most often with T1»_space; T2
When BG is <70mg/dl or 50-55 mg (SEVERE)
2-10% of all DM experience this once / year
What are the symptoms of hypoglycemia
nervous, sweat, tremor, muscle weakness, HA, confusion, coma (25%)
What is the treatment for hypoglycemia
rapid glucose infusion or glucagon infusion
