Diabetes Flashcards
What are the two functions of the pancreas?
- endocrine gland produces hormones
- exocrine gland secretes pancreatic juices for digestion
What hormones are produced by the pancreas endocrine gland?
- insulin
- glucagon
What is the functional unit of the pancreas endocrine gland?
- islets of Langerhans
What cells make up the islet of Langerhans?
- alpha
- beta
- delta
- gamma
What do alpha cells secrete?
- glucagon
What do beta cells secrete?
- insulin
What doe delta cells secrete?
- somatostatin
What do gamma cells secrete?
- pancreatic polypeptide
What stimulates the secretion of insulin?
- high glucose levels
What is insulins mechanism of action?
- drives glucose into the cell via binding to Glut 4 transporters
- inhibits glucagon
What stimulates glucagon secretion?
- low glucose levels
What occurs to make glucagon secretion?
- liver glycogenolysis (breakdown of glycogen to glucose)
What is the relationship between insulin & glucagon?
- inverse/neg feedback
What cells take up glucose?
- skeletal
- cardiac
- liver
- adipose
Summarize DM
- increased blood glucose levels during day
- overall insufficient/absent insulin
- fat, muscle, & liver unable to uptake circulating blood glucose
- lack of glucagon inhibition d/t low insulin
- body in “starvation mode” triggers alternative energy source
- stimulates gluconeogenesis, glycogenolysis & lipolysis
- results in increased FFA/ketoacidosis
What are the counterregulatory hormones?
- glucagon
- catecholamines (i.e. E, NE, cortisol, & GH)
What stimulates glucagon secretion?
- low glucose/hypoglycemia
- strenuous exercise
What inhibits glucagon secretion?
- high glucose
What is glucagons role in the liver?
- gluconeogenesis
- glycogenolysis
- glycolysis
- lipolysis
What occurs as a result of lipolysis?
- stimulates ketogenic effect
- increased acidiv enviornment/ketoacidosis
What is responsible for symptoms of hypoglycemia?
- E
When _____ & _____ fail to adequately raise blood glucose levels, the body releases _____ & _____ which also work to increase blood glucose.
- E & glucagon
- cortisol & GH (potent)
Define DM
- hyperglycemia d/t inability to produce insulin, insulin resistance, OR both
Define DM type I
- hyperglycemia d/t an absence or deficiency of insulin
- beta cell destruction ==> inability to produce insulin
Define DM type II
- combination of insulin receptor abnormalities AND inadequate insulin secretion to compensate
What is DM’s rank on the list of causes of deaths worldwide?
- 5th
At which age does DM type I most commonly present?
- <30 y/o
- peak incidence during preschool & pre-puberty
What is the etiology of DM type I?
- autoimmune
- genetic
- environmental (hx resp infx in infants)
- diet (? cows milk)
Describe the physiology of DM type I
- susceptibility gene on HLA region on chromosome 6
- triggers autoimmune destruction of beta cells
- loss of insulin producing beta cells leads to insulin deficiency
What type of immune response in DM type I?
- Tcell mediated autoimmune attack
What antibodies are present in DM type I?
- ICA
- IAA
- GAD
- tyrosine phosphatases (IA2 & IA2-B)
How can antibody levels help patients?
- screen sibilings
At what point does a DM type I become symptomatic?
- 80=90% beta cell destruction
What is the clinical presentation of DM type I?
- 3 P’s (polyuria, polyphagia, polydipsia)
- unexplained wt loss
- ketonemia
- ketonuria
- fatigue
- nausea
- blurred vision
- paresthesia
- hypotension/orthostatic hypotension
Define polyuria
- increased spilling of glucose in urine
Define polydipsia
- increased plasma hyperosmolality
Define polyphagia
- increased appetite
What are the values for fasting blood glucose?
- normal: 70-100mg/dL
- prediabetes: 100-125mg/dL
- diabetes: >126mg/dL
What are the blood glucose values 2hs s/p eating?
- normal: 200mg/dL
What are the values for a random blood glucose?
- normal: 70-140mg/dL
- diabetes: >200mg/dL
What are the values for OGTT?
- prediabetes: 140-199mg/dL
- diabetes: >200mg/dL
What can a urine dipstick test detect?
- glucose
- ketone
- albumin
Define HbA1c
- % Hb coated with glucose
What are the values of HbA1C?
- normal: < 5.7%
- risk of DM: 5.7-6.4%
- DM: > 6.5%
- goal for DM: <7%
Besides specific glucose tests, what should be ordered for DM pts?
- lipid panel
- renal function
- EKG
- peripheral pulse check
- neuro, pod, & optho consults
What are the primary goals of DM type I tx?
- prevent acute illness
- prevent long term complications
What does it mean to prevent long term complications?
- microvascular complications
- macrovascular complications
What are microvascular complications?
- nephropathy
- neuropathy
- retinopathy
What are macrovascular complications?
- CAD
- peripheral arterial disease
- stroke
What are the types of insulin preparations?
- ultra short/rapid
- short/regular
- intermediate
- long
What are the rapid acting insulin preparations?
- lispro (Humalog)
- aspart (NovoLog)
Discuss the use of rapid acting insulin
- 5-15m prior to a meal
- eat soon after injx
- flexible dosing schedule
- used with long or intermed insulin
- subQ
What is a common side effect of rapid acting insulin?
- hypoglycemia
What are the regular acting insulin preparations?
- Humulin R
- Novolin R
Discuss the use of regular insulin preparations
- 30m prior to a meal
- IV
What are the intermediate acting insulin preparations?
- NPH (Humilin, Novolin)
Discuss the use of intermediate insulin
- BID b/t meals
- combo with regular or lispro for tighter glucose control
What are the long acting insulin preparations?
- glargine (Lantus)
- detemir ( Levemir)
What are long actin insulins best for?
- basal coverage
Discus long acting insulin use
- combo with rapid acting
- given at bedtime
- less nocturnal hypoglycemia
What is the preferred insulin therapy regiment?
- ultrashort with long
Why is self-monitoring required?
- essential to achieve tight glycemic control
What is the secondary line of tx for DM type I?
- diet
What is the primary line of tx for DM type II?
- diet
Why is exercise important in DM?
- improves utilization of CHO & lipids
What is a concern of DMs exercising?
- predispose them to hypoglycemic episodes so start slow, check glucose, take in extra carbs, reduce insulin prior to starting
What is the surgical intervention for DMs?
- pancreas transplant
What are the glucose level goals for DM?
- preprandial & after night fast: 90-130mg/dL
- 1hr postprandial: 180mg/dL
- 2 hr post prandial: 150mg/dL
- HbA1C: <7% or 8% w/ hx of hypoglycemia, short life expect, elderly, CVD, many co-morbidities
What is a serious concern with insulin therapy?
- hypoglycemia (blood glucose < 54mg/dL)
What is stimulated at blood glucose < 54mg/dL?
- ANS
i. e. tachycardia, palpitations, sweating, tremulousness, nausea, hunger
What is stimulated at blood glucose < 50mg/dL?
- neuroglycopenic
i. e. difficulty speaking, irritability, blurred vision, H/A, tiredness
What are the treatments for insulin induced hypoglycemia?
- simple sugar (IV bolus 50% or tabs dextrose)
- glucagon (1mg ampule IM or SC)
What can patients with DM develop?
- insensitivity to hypoglycemia
How does insensitivity to hypoglycemia develop?
- counterregulatory hormones fail to respond
- loss of ability to secrete glucagon
- repeated episodes of hypoglycemia leads to blunted E response
What is the treatment for hypoglycemia insensitivity?
- allow a few weeks of higher glucose levels to recalibrate ANS
What are the 3 pre-breakfast hyperglycemias?
- Waning effect
- Dawn phenomenon
- Somogyi effect
Define Waning effect
- waning levels of circulating insulin at night leads to hyperglycemia
Define Dawn phenomenon
- decreased tissue sensitivity to insulin during the night
Define Somogyi effect
- nocturnal hypoglycemia which triggers counterregulatory hormones
i. e. pt takes insulin but doesn’t eat a bedtime snack
Describe the body changes that occur during sleep cycle
- b/t 3a-8a, increase amount of counterreg hormones
- counterreg hormones work against insulin
- increased release of counterreg hormones when bedtime insulin is wearing out leads to prebreakfast hyperglycemia
What is a complication of DM type I?
- diabetic ketoacidosis (DKA)
Describe the pathophysiology of DKA
- lack of insulin
- elevated glucagon
- lipolysis
- cerebral edema in severe cases
What are the symptoms of DKA?
- n/v
- thirst/polyuria
- abd pain
- dyspnea
What are the physical findings of DKA?
- tachycardia
- dehydration/hypotension
- tachypnea/kussmal resp/fruity breath
- lethargy/ obtundation/ cerebral edema/coma
What are the labs of DKA?
- glucose: 350-900mg/dL
- blood pH: 6.9-7.2
- serum bicarb: <15mEq/L
- ketonemia
- hyperkalemia (5-8mEq/L)
What is the tx of DKA?
- restore plasma vol & tissue perfusion via IV fluids
- reduce blood glucose & osmolality via regular insulin IV
- correct acidosis & replenish electrolytes via bicarb tx
- ID & tx precipitating factors
Define DM type II
- metabolic disorder that is characterized by hyperglycemia d/t insulin resistance & relative lack of insulin
What is the etiology of DM type II?
- obese/overweigh
- lack of physical activity
- poor diet
What are the risk factors for DM type II?
- > 45 y/o
- > 120% desirable body weight
- increased hip:waist
- (+) family hx in a 1st deg relative
- hx of impaired glucose tolerance test or fasting glucose
- HTN
- dyslipidemia
- hx of gestational diabetes
- genetics
- secondary diabetes
What is the pathophysiology of DM type II?
- body produces insulin but cell receptors have decreased sensitivity to insulin’s action
- beta cells continue to secrete insulin –> hyperinsulinemia
- overtime, beta cells fail –> decreased insulin
How do many DM type II’s remain asymptomatic?
- pancreas is able to keep up with body’s insulin requirement and keeps blood glucose in normal range
What does constant state hyperglycemia + lack of insulin cause?
- stimulates glucagon secretion & hyperglucagonemia as a way to supply “starving” cells with fuel via gluconeogenesis
What is the onset of DM type I v. II?
- I: sudden
- II: gradual
What is the age at onset of DM type I v. II?
- I: mostly in children
- II: mostly in adults
What is the body habitus of DM type I v. II?
- I: thin or normal
- II: often obese
Is ketoacidosis more common in DM type I or II?
- I: common
- II: rare
Are antibodies present in DM type I or II?
- usually present in I
- absent in II
What is the level of endogenous insulin for DM type I & II?
- low or absent in I
- normal, increased, or decreased in II
What is the clinical presentation of DM type II?
- initially asymptomatic
- 3 P’s
- fatigue
- blurred vision
- neuropathy
- yeast/fungal infx
- CVD
- dyslipidemia
- poor wound healing
- acanthosis nigricans
What is the diagnostic criteria for DM type II?
- FPG > 126mg/dL (repeated 2x) OR - HbA1C >6.5% (repeated 2x) - 2hPG >200mg/dL after a 75g OGTT - random PG > 200mg/dL in pt w/ classic sx
What are the glucose treatment goals for DM?
- blood glucose near normal
- HbA1C < 7%
What are the initial tx options for DM type II?
- low CHO, low fat, CHO counting
- smoking cessation
What is step 1 of DM type II tx?
- metformin + life changes
What is step 2 of DM type II tx?
- add insulin or other oral antihyperglycemics
What are the medications for DM type II tx?
- biguanides
- sulfonylureas
- meglitinide derivatives
- alpha-glucose inhibitors
- TZDs
- GLP-1
- DPP-4 inhibitors
- SGLT-2 inhibitors
What is the first medication started for a newly dx’d DM type II?
- biguanides (metformin)
What is the MOA of biguanides?
- decreases hepatic gluconeogenesis production
- decreases intestinal absorption of glucose
- improves insulin sensitivity
- lowers basal & postprandial PG levels
What are examples of sulfonylureas?
- glyburide
- glipizide
- glimepiride
What is the 2nd medication given to a type II DM patient?
- sulfonylureas
What is the MOA of sulfonylureas?
- insulin secretagogues
- stimulates insulin release from beta cells
What is a common side effect of sulfonylureas?
- hypoglycemia
What is the MOA of meglitinide derivatives?
- short acting insulin secretagogues
uncontrolled DM type II patient is on biguanide (metformin) with sulfonylurea allergy, what is the next tx?
- meglitinide derivatives
What is the MOA of alpha-glucosidase inhibitors?
- delay sugar absorption
What is the last resort of DM type II tx?
- TZD
What are examples of TZDs?
- pioglitazaone (Actos)
- rosiglitazone (Avandia)
What is the MOA of TZDs?
- insulin sensitizers
- increase insulin cellular transport
- decrease tryglyceride
- increase HDL level
What patient population are TZDs contraindicated and why?
- advanced CHF
- wt gain & fluid retention
What is an example of GLP-1?
- exenitide
What is the MOA of GLP-1?
- glucagon like peptide -1
- increases insulin response to glucose
- increases insulin sensitivity
- decreases glucagon
What is the MOA of DPP-4?
- dipeptidyl-peptidase-4
- inactivates GLP1
What is an example of DPP-4 inhibitor?
- sitagliptin
What is the EFFECT of DPP-4 INHIBITOR?
- prolongs GLP-1 action
What is the MOA of SGLT-2?
- inhibit glucose reabsorption in the proximal tubule
- increased glycosuria
- decreased hyperglycemia
What are examples of SGLT-2s?
- Invokana (canagliflozin)
- Farxigan (dapagliflozin)
What are side effects of SGLT-2s?
- volume contraction from glycosuria & hypotension
- UTIs
What type of insulin is used to start patients on insulin therapy?
- basal or intermediate
What is hyperosmolar hyperglycemic state?
- HHS
- relative insulin deficiency
What does HHS lead to?
- volume depletion
- hemoconcentration
What are the risk of complications of HHS?
- coma
- death
What distinguishes DKA from HHS?
- level of acidosis
What is the tx for HHS?
- IV fluids
- insulin
- manage underlying conditions
What are the long term microvascular complications of both types DM?
- retinopathy
- neuropathy
- nephropathy
- HTN
What are the long term macrovascular complications of both types of DM?
- CAD
- cerebrovascular disease
- peripheral vascular disease
What ocular diseases can occur from DM?
- diabetic cataracts
- diabetic retinopathy (non-proliferative & proliferative)
What distribution will diabetic neuropathy present as?
- glove & stocking
How are diabetic neuropathy sx alleviated?
- improved glycemic control
- foot protection & inspection
What is the tx of peripheral neuropathy?
- TCA (tricyclic antidepressants)
How is diabetic nephropathy diagnosed?
- urine spot >30-300mcg/mg (microablunuria)
What is the treatment of diabetic nephropathy?
- hemodialysis
- HTN control
What is the tx of diabetic HTN?
- ACE inhibitors
- ARBs
Why are ACE inhibitors or ARBs given to patients w/o HTN?
- renal protective characteristics
What is the tx of CAD/cerebrovascular/PVD?
- control HTN
- ASA
- statins
What are patients with both PVD & peripheral neuropathy at risk for?
- diabetic foot ulcers, poor wound healing
- gangrene
- digit/limb amputation
What is diabetic foot ulcer/Charcots Foot?
- d/t periarticular fx & obesity
- decreased foot sensitivity to pain and pressure
- osteoclastic activity
What is the tx of Charcots Foot?
- mechanical unloading
- wound tx
- abx
- debridement