Diabetes Mellitus Flashcards
Is T1DM an absolute insulin deficiency? Explain answer
Yes
Panc beta cell destruction by autoantibodies results in no endogenous insulin production
What susceptibility genes are involved in T1DM?
HLA-D (>90% of T1DM pts)
Explain the trigger(s) for T1DM and pathophysiology
In genetically susceptible individuals, environmental triggers like a viral infection and diet can lead to immune-mediated beta-cell destruction
viral infection ➔ destroy beta cells ➔ expose autoantigens to immune system ➔ continued destruction
What does the islet pathology look like in T1DM?
Insulitis, shows immune cell infiltrates around and within the islets
Define T2DM
A relative insulin deficiency due to a insulin resistant cells
What are 5 key risk factors for developing T2DM?
- Obesity/metabolic syndrome
- First-degree relative with DM
- HTN
- Hyperlipidemia
- PCOS
What causes T2DM?
Not fully understood!
Thought that excess adipose tissue ➔ lipolysis ➔ adipokines ➔ inflammation ➔ related to insulin resistance
There seems to be a genetic factor ➔ twin studies, having a twin with T2DM increases the risk of developing T2DM
Explain the progression of T2DM with insulin resistance
hyperglycemia develops when insulin cannot compensate for insulin resistance
- Cells not responsive to insulin ➔ no glucose intake
- pancreas attempts to compensate, so beta-cells produce more insulin
- beta cells can no longer compensate and start shrinking (this takes a long time)
rare: beta cells cannot produce any insulin
Age of onset for T1DM vs T2DM
<25 yrs vs usually older adults
Weight for T1DM vs T2DM
usually thin vs >90% are at least overweight
What is c-peptide and how would this lab result differ for T1DM vs T2DM
c-peptide: connecting protein in proinsulin ➔ only present in endogenous insulin
undetectable/low in T1DM – not producing endogenous insulin because beta cell destruction
normal/high in T2DM – producing more insulin than normal from beta cells that are trying to compensate for the insulin resistance
how frequent do T1DM and T2DM have a family history of DM?
T1DM: infrequently (5-10%)
T2DM: frequent (75-90%)
What are the 3 P’s for hyperglycemia s/s (list them)
polyuria, polydipsia, polyphagia
p/p for polyuria
increased glucose in plasma ➔ increased glucose excretion + water following in urine bc glucose is a solute ➔ increased frequency of urination
increased osmolarity in urine ➔ increased fluid excretion because water is drawn to areas of higher osmolarity
p/p for polydipsia
bc of polyuria ➔ dehydration ➔ signal for thirst and to drink
p/p for polyphagia
cellular need for energy ➔ glucose not being transported into cells ➔ signals to eat
*not typically a main pt concern
what are some s/s of dehydration you’d see in DM? some specifically in peds?
- increased thirst
- dry mucous membranes
- dark coloured urine
- dizziness/light-headedness
- decreased pulses, prolonged capillary refill
peds:
1. irritable/altered mental status
2. sunken eyes/fewer tears
3. sunken fontanelle
Why are UTIs common in DM pts?
Because increased excretion of high glucose sugar ➔ makes it inflamed and dry and prone to infection
What is the dawn phenomenon?
morning hyperglycemia due to increased insulin antagonist hormones (growth hormone, cortisol, and catecholamines) during the night to release more sugar
they have normal blood sugar during the night
What is somogyi phenomenon?
Evening hypoglycemia due to the insulin or oral diabetic medication taken before bed, and a rebound morning hyperglycemia due to the body’s response to increased stress hormones like cortisol and epi
What does first presentation of T1DM look like?
usually with symptomatic hyperglycemia (polyuria, polydipsia, polyphagia) and sometimes in DKA (hyperglycemia, ketoacidosis)
What does first presentation of T2DM look like?
May have hyperglycemic s/s (polyphagia, polyuria, polydipsia)
May be incidentally found w/ routine testing
May initially present w/ diabetic cx (retinopathy, nephropathy, or neuropathy) or HHS
What are 2 signs of insulin resistance (T2DM)
acanthosis nigricans: darkened skin in the armpit/back and sides of neck
skin tags in the same area
What ix can we use specifically to differentiate between T1DM and T2DM?
Autoimmune markers will tell us if its T1DM
- Anti-glutamic acid decarboxylase (more commonly ordered)
- anti-islet cell (less commonly ordered
Consider ketones - if first presentation with s/s of severe hyperglycemia ➔ potentially DKA
- urine dipstick for acetoacetate
- serum for Beta-hydroxybutyrate
What tests can we use according to the Diabetes Canada 2018 Clinical Practice Guidelines to diagnose DM?
- Fasting plasma glucose
- Oral Glucose tolerance test - mainly gestational diabetes
- HbA1C
- Random plasma glucose
What lab work values would you consider to be diabetic for the Diabetes Canada Guidelines for all 4 tests?
A1C: >= 6.5%
FGP: >=7 mmol/L
OGTT: 11.1 mmol/L
Random GP: 11.1 mmol/L
Why is knowing you’re pre-diabetic important?
because 50-80% of ppl can revert to normal glucose tolerance with proper wt loss and lifestyle modifications ➔ so they never progress to DM or have to take meds
What is pre-diabetes?
- impaired glucose tolerance
- these indiv are at a high risk of developing DM and its cx
what lab values would show you pre-diabetes according to the guidelines?
A1C: 6-6.4%
FGP: 6.1-6.9 mmol/L
OGTT: 7.8-11 mmol/L
What kind of follow-up/monitoring tests would you want to organize for DM patients?
- regular clinic visits
- A1C + blood glucose tests every 3 months
- Lipid profile with every bloodwork ➔ if older than 40yrs/higher risk factors, or has T2DM
- serum creatinine ➔ to calculate eGFR
- urine analysis ➔ for albumin to creatinine ratio ➔ monitoring nephrophathy cx)
- annual eye exam ➔ monitoring retinopathy
- diabetic foot exam w/ every visit
What is the target range for HbA1c according to the guidelines?
<7.0%
What is the target range for FPG according to the guidelines?
4-7 mmol/L
What is the target range for OTT according to the guidelines?
5-10 mmol/L
What is the target range for LDL-C according to the Diabetes guidelines?
< 2.0 mmol/L
What is the target range for BP according to the diabetes guidelines?
<130/80
What are the ABCDES of Diabetes Care?
A1C target <7%
Blood pressure <130/80
Cholesterol LDL<2.0 mmol/L
Drugs for CVD risk reduction
Exercise goals and healthy eating
Smoking cessation and screening for complications
