100 terms

Endocrine pancreas 1

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glucagon is made by
alpha islet cells
alpha islet cells take up what % of cellularity
20%
When is glucagon released (specific)
BG<70-80 mg/dL (e.g. fasting)
primary target(s) of glucagon
liver
secondary target(s) of glucagon
skeletal muscle
goals of glucagon
prevent hypoglycemia, increase BG
glucagon mechanism/promotes
gluconeogenesis, glycogenolysis
Insulin is made by
beta islet cells
beta islet cells make up __% of cellularity
80%
insulin is released/increased when (specific)
BG> 110-120 mg/dL (e.g. postprandial)
primary target(s) of insulin
skeletal muscle
secondary target(s) of insulin
adipose, liver
goals of insulin
prevent hyperglycemia, decrease BG
insulin mechanism/promotes
glycogenesis, lipogenesis
most important signal for insulin release
blood glucose
definition of diabetes
group of metabolic disorders sharing the common feature of hyperglycemia
type 1 DM onset
usually in childhood/adolescence (can be an adult)
type 1 DM weight
usually normal to lean
type 1 DM insulin levels
deficient/declining at dx
type 1 DM antibodies present?
yes;
anti-IA2, anti-GAD65, etc.
anti-IA2
type 1 DM
anti-GAD65
type 1 DM
Type 1 DM most common emergent situation
DKA
Genetics of type 1 DM
MHC class II linkage insulin, receptor gene mutations
mechanism type 1 DM
beta cell destruction >> insulin deficiency (generally autoimmune)
histology type 1 DM
insulitis (lymphocytic infiltration , islet atrophy
type 2 DM onset
usually in adults, but getting younger
type 2 DM weight
80% are obese
type 2 DM insulin levels
increased early, progressively decline
type 2 DM autoantibodies?
not usually helpful
emergent situation most frequent in type 2 DM
usually non-ketotic HHS (Hyperglycemic hyperosmolar syndrome)
genetics of type 2 DM
multigenic. strong predisposition (>T1!)
Mechanism of type 2 DM
insulin resistance> compensation fails > collapse and deficiency
histology of type 2 DM
amyloid deposition (mild beta-cell depletion)
gestational vs. pre-existing DM
pre-exisiting DM in pregnancy is either known prior to conception or found before/in week 12 screening

gestational DM= hyperglycemia and sx with onset in the 2nd or 3rd trimester
maternal risks for developing GDM (7)
>25 yo
prior GDM
being overweight/obese
ethnicity (higher risk in AA, Hispanic, Asian
# para
sedentary lifestyle
smoking
age and risk for developing GDM
>25 yo
age and risk for developing GDM
>25 yo
Risks if GDM is diagnosed
1. many-fold increased risk of DM later in life
2. MAY represent a developing overt DM (implied)
3. many-fold increased lifetime risk of retinopathy, CVD
fetal risks if hyperglycemia and DM in first trimester (Overt DM)
miscarriage, stillbirth
congenital abnormalities of the heart, neural tube, kidneys, GI tract
fetal risks if hyperglycemia and DM in 2nd or 3rd trimester (gestational and overt DM)
macrosomia
birth asphyxia
shoulder dystocia
respiratory distress
hypoglycemia
polycythemia
neonatal jaundice
prediabetes=
fasting glucose and glucose tolerance impaired
prediabetes and weight
usually, the pt is obese
prediabetes has high association with
central/core obesity
dyslipidemia, increased CV risk, and HTN
true or false: there are often other endocrine abnormalities present in prediabetes
true
true or false: prediabetes is somewhat reversible
true; depending on other diseases and risk factors
when making DM dx, nothing beats
thorough hx and a physical exam (presentation, sx, and historical narratives)

lab testing can support your findings
3 P's of DM
polydipsia
polyphagia
polyuria
polydipsia in DM because
osmoreceptors sense increased blood osmolarity--> increased thirst
polyphagia in DM because
cells cannot access glucose present
negative energy balance--> hunger
probably adipose role
polyuria in DM because
sugar spill into urine
glucose pulls water--> net water loss--> osmolarity--> thirst
glycated Hgb measures
Hgb irreversibly bound by glucose
glycated hemoglobin estimates
average blood glucose level (90 days)
glycated hemoglobin is performed in/at
central lab
glycated hemoglobin convenient?
yes
glycated hgb is recommended for dx in
adults
pregnancy <12 wks
(peds?)
glycated hgb screening tool?
yes, for most
monitoring interval for glycated hgb
every 90 days (no less)
fasting plasma glucose measures
glucose in circulation
fasting plasma glucose estimates
glycemia at point of sampling
fasting plasma glucose is performed in/at
central lab
point of care
or home
fasting plasma glucose convenient?
usually
fasting plasma glucose recommended for dx in
adults
(GDM)
(Peds)
fasting plasma glucose as a screening tool?
generally good
fasting plasma glucose monitoring interval?
hours; pre/postprandial, daily
oral glucose tolerance test measures
glucose in circulation over multiple time points
oral glucose tolerance test estimates
glucose tolerance (insulin response)
oral glucose tolerance test is performed in/at
central lab
oral glucose tolerance test convenient?
no
oral glucose tolerance recommended for dx in
pediatrics
CYSTIC FIBROSIS
GDM
oral glucose tolerance test a screening tool?
for GDM in 2nd trimester
oral glucose tolerance test monitoring interval?
generally N/A
exception: CF annual 'til dx
Glycated hgb description
irreversibly bound to hgb, but doesn't alter function.
glycated hgb reported as
a %
glycated hgb unreliable in pts with
hemoglobinopathy
increased RBC turnover (false decrease)
decreased RBC turnover (false increase)
recent transfusion
Glucose testing
types/blood specimen
or urine (randome)
glucose "types," blood specimen
fasting, S/P
non-fasting, S/P
post-prandial, S/P
timed, after glucose load in OGTT, (S/P)
whole blood (similar to S/P)
glucose urine, random
part of all U/A dipstick assessments
home-"dip-strip" tests
historic gold standard for DM dx in all pts
oral glucose tolerance test
oral glucose tolerance test current use
mostly used in GDM workups and "tricky" cases (e.g. children with CF not yet diagnosed)
requirements when testing general population for GDM with OGTT
75g of glucose
measure baseline/fasting, 1, and 2 hrs after
GDM screen (ACOG, ADA) with OGTT
50 g of glucose, measure only 1 hr after
GDM confirmation (ACOG, ADA) with OGTT
100g of glucose, measure baseline, 1, 2, and 3 hr after
Glycated Hgb/A1c cutoffs
prediabetes; 5.7-6.5%
Diabetes: >=6.5%
GDM: NOT USED. overt DM in pregnancy, keep <6%
Fasting plasma glucose cutoffs
prediabetes: between 100-125 mg/dL
diabetes >=126 mg/dL
GDM: cutoffs the same as for prediabetes and DM
2-hr plasma glucose after 75g OGTT cutoffs
prediabetes: >140 and <200 mg/dL
diabetes >=200 mg/dL during the test, any time point
one-step method with dedicated cuttoffs for GDM
random plasma glucose cutoffs
prediabetes: not applicable
diabetes >= 200 mg/dL AND symptoms
GDM: not applicable
50g OGTT cutoffs
prediabetes and diabetes not applicable
GDM: 2 step method for screen
100g OGTT cutoffs
prediabetes and diabetes not applicable
GDM: 2 step method for confirmation
treatment approaches to prediabetes
diet, exercise
glycemic monitoring
periodic A1c monitoring possible
(metformins, statins)
maintenance of glycemia PREVENTS COMPLICATIONS
treatment approach to type 1 DM
diet and exercise
insulin
glycemic monitoring to prevent complications
supportive care
treatment approach to type 2 DM
diet and exercise
Rx hypoglycemic
statins
glycemic monitoring to prevent complicaitons
(insulin)
(bariatric surgery)
DKA
usually Type 1 DM
most common cause of death in children/adolescents with T1DM
~50% of deaths in pts <24 yo
most common cause of death in children/adolescents with T1DM
DKA
mortality DKA
5%; usually due to underlying cause
mortality HHS
15%; usually due to underlying cause
triggers for acute crises in DM
infection, ~50%
acute illness
therapeutic noncompliance
alcoholism, drug abuse
DKA develops rapidly, HHS
Dehydration, tachycardia, CNS sx (alert-obtunded, but progresses), vomiting and "acute abdomen," kussmaul respiration, fruity/acetone breath
DKA
Dehydration, tachycardia, CNS sx (alert-obtunded, but progresses)
HHS
signs of DKA and HHS
both with dehydration, tachycardia, hypotension. CNS sx vary from alert-obtunded, but progress in both.
Vomiting, "acute abdomen" in up to 75% of DKA, but less common in HHS
DKA has kussmaul respiration and fruity/acetone breath