Diabetes Mellitus Flashcards
What are the sub classifications of type 1 DM?
Type 1a and 1b
What are the characteristics of type 1a DM?
Most common subtype of type 1 (90-95%) and is immune based (autoimmunity)
What are the characteristics of type 1b DM?
Idiopathic and affects approximately 5-10% of people with type 1
How common is type 2 DM?
Very common, 90%
What is the etiology of DM?
Complex trait (multiple genes and something in the environment)
What are the etiologys for type 1 DM? (3)
Familial (immediate family members have a 10x increased risk)
Insulin gene on chromosome 11 (10%)
MHC genes on chromosome 6 (40%)
What is the etiology of type 2?
Glucokinase gene on chromosome 7 (50%- codes for enzyme that phosphorases glucose in target cell)
What is prediabetes (for type 2) described by? (3)
IFG 6.1-6.9
HbA1C 6-6.4%
IGT 7.8-11
What is metabolic syndrome? Do all features need to be present for it diagnosed?
It is a predisposition to type 2 and CV disease and not all features need to be present for it to be diagnosed
What is metabolic syndrome defined by?
IFG IGT Insulin resistance HTN Abdominal obesity (f >88cm + m>102cm) Hyperlipidemia
What is the definition of insulin resistance?
Insulin is unable to bring about a hypoglycaemic response in a hyperglycaemic state
What are the characteristics of type 1 DM?
Early age onset
Autoimmune destruction of beta cells (insulin autoantibodies and islet cell autoantibodies destroy B cells)
Since it is autoimmune it requires a genetic predisposition + some sort of environmental infection? = complex trait
What are the characteristics of type 2 DM?
Adult onset, B cells are mostly intact
Can have normal, increased or decreased levels of insulin
Type 1 DM is ________ insulin deficiency while type 2 DM is ________ insulin deficiency
Absolute
Relative
In type 2 DM what are 3 factors that can cause a relative insulin deficiency?
Delayed section of insulin
Defective target cell
Insulin resistance
What is something the liver does during hyperglycaemia as a result of the cells feeling they lack glucose?
Secrete glucose (glucogenesis)
What is the renal threshold for glucose? At what point would glucose appear in the urine?
RT- 10. Anything above 10 and glucose will appear in the urine
What is the patho of type 1 and 2 DM? Note the patho for polyuria & polydipsia
Insulin deficiency -> impaired glucose utilization and increased hepatic glucogenesis -> hyperglycaemia -> RT exceeded -> glucosuria -> inc OP in filtrate -> inc fluid enters filtrate -> polyuria -> dehydration -> polydipsia
What is the patho for type 1 and type 2? Note ketoacidosis and polydipsia and polyuria
Mobilization of lipid and proteins -> inc lipid and protein metabolites (ketones) -> accumulation of ketones -> ketoacidosis -> ketonuria -> inc OP infiltrate -> inc fluid enters filtrate -> polyuria -> dehydration -> polydipsia
Ketoacidosis -> acidotic coma and death
What are manifestations of DM?
3 ps
Weight loss (losing glucose & calories in urine)
Other complications
What are acute complications of DM?
Hypoglycaemia
Diabetic ketoacidosis (DKA)
Hyperosmolar hyperglycaemic state (HHS)
What can acute complications lead to quickly?
Death
What is the etiology of hypoglycaemia?
Missed meal
Insulin overdose
Overexertion
What is the treatment for hypoglycaemia? Mild and severe.
Mild: 15g CHO PO
severe (
What is a complication of hypoglycaemia and what is a treatment?
Hypoglycaemic coma because the brain is deprived of glucose
1 mg glucagon SC/IM to stimulate glucogenesis
What are 3 derangements of DKA
Hyperglycaemia
Ketosis
Ketoacidosis
What must be in place for DKA to occur?
Decreased insulin and excessive glucagon
What is the patho of DKA? (Note protein breakdown side of patho)
Decreased glucose uptake -> protein breakdown -> gluconeogenesis -> hyperglycaemia -> water and electrolyte loss -> dehydration -> circulatory failure
What is the patho of DKA? (Note lipid breakdown portion)
Lipolysis -> glycerol and FFA -> gluconeogenesis & circulatory shock from glycerol -> ketones from FFA -> metabolic acidosis -> CNS depression and coma
What are the final outcomes of DKA?
Circulatory shock, CNS depression & coma
Who does HHS most commonly affect?
People with type 2 DM and elderly
What occurs in HHS and why does it result?
Hyperglycaemia causing hyperosmolarity leading to increased glucose concentration in the blood
Results from increased CHO intake
What can occur if HHS becomes exacerbated?
Increased insulin resistance
What is the patho of HHS?
Severe hyperglycaemia -> hyperosmolarity -> cellular fluid efflux -> glucosuria -> polyuria (inc op) -> dehydration
Does ketoacidosis occur in HHS? Why/why not?
No because lipid reserves are not being broken down because CHO are present for metabolism
What are chronic complications of DM?
Vascular damage Retinopathy Nephropathy Neuropathy Infection
When do the chronic complications set in? Do these eventually lead to death?
They set in approximately 15 years after onset and they result in death
Why does vascular damage occur as a complication of DM? (3)
Altered metabolism -> ketones attach to endothelium in BV -> thicken cap wall and alter trans cap exchange -> inflm and damage
Glycoslated proteins attract platelets which aggregate on them -> impedes perfusion
Growth of anaerobic bacteria
What causes retinopathy as a complication of DM?
Cap damaged from ketones and glycoslated proteins -> aneurysm -> rupture -> visual impairment
What causes nephropathy as a complication of DM?
Glomerular damage from build up of precipitates -> decreased renal fx -> renal failure
What causes neuropathy as a result of a complication of DM?
Neural ischemia as a result of inadequate perfusion to neurons in brain -> some demyelination -> poor conduction -> decreased sensation
What causes HTN as a complication of DM?
BV wall affected
What causes CAD as a complication of DM?
Hyperlipidemia due to altered metb -> atherosclerosis -> MI
What causes a CVA as a complication of DM?
Hyperlipidemia -> atherosclerosis -> CVA
Why are people with DM more susceptible to infections? (3)
Glucosuria -> UTI
Neuropathy
Impeded perfusion, vascular insufficiency
Impaired leukocyte fx
What is the first, second and third ways to control hyperglycaemia?
Lifestyle mods must stay in place throughout all treatment
Metformin if a1c >7% after 2-3 months of lifestyle mods
Metformin and insulin if a1c >9%
What is the treatment for type 1 DM?
Insulin
True or false: diabetes is the most common endocrine disorder?
True
