Lecture 18: Endocrine System I Flashcards
(100 cards)
1
Q
endocrine pancreas= __
A
islet of langerhans
2
Q
what is function of alpha cells
A
secrete glucagon—> increase BG
3
Q
function of beta cells
A
secrete insulin—> decrease BG
4
Q
What are the 3 sources of blood glucose
A
- Intestinal absorption
- Hepatic production
- Kidney production
5
Q
how do glucocorticoids affect BG
A
increase
6
Q
how do catecholamines affect BG
A
increase
7
Q
how does growth hormone affect BG
A
increase
8
Q
A
9
Q
which tube measures plasma BG
A
green or grey top
10
Q
serum or plasma to measure BG needs to be separated from RBC within
__post collection
A
30-60 mins
11
Q
why does serum and plasma need to be separated from RBC within 30-60 minutes when measuring BG
A
glycolysis in RBC causes glucose to decrease by 5-10%/hr
12
Q
what are the 4 broad causes of hyperglycemia
A
- Physiologic
- DM
- Pharmacological or toxicological
- Other: pancreatitis, pancreatic carcinoma, endocrine
13
Q
what are some physiologic causes of hyperglycemia
A
- Post-prandial
- Excitement/fright- catecholamine mediated
- Stress or steroid associated- glucocorticoid mediated
- Diestrus: progesterone mediated
14
Q
type 1 DM is targeted __destruction
A
Beta cell
15
Q
type 1 or 2 DM: lack insulin/deficiency, insulin-dependent
A
type 1
16
Q
what are the causes of type 1 DM
A
17
Q
is type 1 DM most common in dogs or cats
A
dogs
18
Q
type 1 or type 2 DM: insulin resistance secondary to chronic inflammation
A
type 2
19
Q
A
20
Q
what is type 2 DM associated with
A
- Amyloid deposition
- Glucotoxicity
- Beta cell failure
21
Q
what is major risk factor for type2 DM
A
obesity
22
Q
is type 2 DM more common in dogs or cats
A
cats
23
Q
what are some examples of things that can cause pharmacological or toxicological hyperglycemia
A
- Oral or IV glucose
- Glucocorticoids
- Xylazine
- Progestins
- Thyroxin
- Ethylene glycol
24
Q
how does pancreatitis or pancreatic carcinoma cause hyperglycemia
A
- sufficient beta cell damage—>decrease insulin production (DM)
- Catecholamines, cortisol, glucagon
25
What Endocrine disorders can cause hyperglycemia
1. Cushings
2. Hyperthyroidism
3. Bovine mil fever
4. PPID
26
how does cushings cause hyperglycemia
cortisol—> insulin resistance and increased gluconeogenesis
27
how does bovine milk fever cause hyperglycemia
need calcium to convert pro-insulin to insulin
Stress (cortisol)
28
how can you use clinical signs to differentiate DM vs other causes if hyperglycemia
DM: PU/PD, weight loss, polyphasic
Excited/stress?
Overweight?
29
is fasting hyperglycemia consistent with DM or other causes of hyperglycemia
DM
30
degree of hyperglycemia with __ is usually mild to moderate, if glucose concentration is > __ think about __
Stress or excitement, >300-400, DM
31
what other 2 things can you measure to differentiate DM vs other causes of hyperglycemia
glucosuria and ketonuria
32
what is hyperglycemia glucosuria
when BG is > renal threshold
33
significant stress or excitement can cause glucosuria but usually __ on urine dipstick
trace or +1
34
__glucosuria on dipstick supportive of DM
marked, 3 or 4+
35
if you have __ and __ think DKA
ketonuria and hyperglycemic glucosuria
36
DM patients on __ may experience euglycemic DKA
SGLT2 inhibitors
37
glucosuria without hyperglycemia supports __not___ in absence of SGLT2 therapy
renal tubular glucosuria
38
what is used as a marker of blood glucose concentration during circulating lifespan of protein over 2-3 weeks
fructosamine
39
increased fructosamine is good indicator of __hyperglycemia
sustained hyperglycemia
40
fructosamine WRI supports __
transient hyperglycemia
41
decreased fructosamine supports __
persistent hypoglycemia
42
what other factors can cause false decrease or increase in fructosamine
false decrease: hypoproteinemia or hyperthyroidism
False increase: hypothyroidism or hyperglobulinemia
43
what is serial glucose curve and what does it help assess
measurement of BG concentrations at 1-2hr intervals throughout day
Helps assess efficacy and appropriateness of insulin dosage
44
what is continuous glucose monitoring
SQ sensor that measures interstitial fluid glucose concentrations every 5 minutes
45
What are serum insulin concentrations used to dx
insulinoma and in a horse suspected to have insulin resistance
46
what is CBC typically for DM patient
usually normal
May see inflammatory leukon with concurrent pancreatitis or infection
47
what is serum biochemistry like for patient with DM
1. Hyperglycemia
2. Hypercholesterolinemia
3. Hypertriglyceridemia
4. Increase ALT and/or ALP
5. Azotemia pre renal vs renal
48
what does urinalysis of DM patient typically show
1. USG >1.020
2. Glucosuria
3. +/- ketonuria
4. +/- proteinuria
5. +/- evidence of UTI: pyuria, Hematuria, and or bacteriuria
49
what is pathogenesis of DKA
lack of insulin or insulin resistance—> decreased glucose in cells—> negative energy balance—> lipolysis
50
what signs are included in establishing dx of DKA
1. Systemic illness
2. Persistent fasting hyperglycemia and glucosuria
3. Ketonuria
4. Metabolic acidosis (titrational)
51
what are the mechanisms of hypoglycemia
1. Decreased glucose production
2. Decreased intake
3. Increased glucose utilization by tissues
52
what is one of the most common cause of hypoglycemia
delayed separation of serum from RBCs
53
what can cause decrease production of glucose leading to hypoglycemia
1. Liver failure or insufficiency- cirrhosis or PSS
2. Juvenile hypoglycemia
54
What are some causes of increased use of glucose leading to hypoglycemia
1. Excessive insulin administration
2. Increased insulin secretion (insulinoma)
3. Xylitol
4. Addisons
5. Sepsis
6. Bovine ketosis
7. Exertional
8. Pregnancy
55
describe normal production of T3 and T4
1. TRH released from hypothalamus
2. TSH released from pituitary
3. T3 and T4 released form thyroid glands
56
What makes up total t4
free T4 and protein bound t4
57
what test is used to rule out hypothyroidism in dogs and rule in hyperthyroidism in cats
total t4 (TT4)
58
what test uses equilibrium dialysis to measure T4
free T4 (fT4)
59
what test is used in conjunction with TT4 and fT4 to evaluate for hypothyroidism
TSH
60
is hypothyroidism more common in dogs or cats
dogs
61
>95% cases of hypothyroidism are __
primary hypothyroidism
62
what are the causes of primary hypothyroidism
1. Immune mediated lymphocytic thyroiditis
2. Idiopathic atrophy
63
what is cause of secondary hypothyroidism
pituitary disease- decrease TSH
64
what is cause of tertiary hypothyroidism
hypothalamic disease- less TRH
65
When Should we consider testing for hypothyroidism
1. Dermatological signs >85% of cases
2. Obesity
3. Lethargy
66
67
What is TT4 in dogs with hypothyroidism
low
68
can we use TT4 to dx hypothyroidism in dogs
no
69
if total T4 is low in dogs consider __
hypothyroidism, non-thyroidal illness or drugs
70
if total t4 is normal in dogs then __
rule out hypothyroidism
71
what is non-thyroidal illness/euthyroid sick syndrome
any illness- acute or chronic that will decrease total t4
72
what drugs can cause decrease in total t4
glucocorticoids
Phenobarbital
73
what breeds have lower T4 and fT4
greyhounds and sighthounds
74
how does age affect t4
decreases
75
76
what is fT4 by ED concentration in dogs with hypothyroidism
low
77
what is fT4 by ED in dogs with non-thyroidal illness
normal
78
if you have a low TT4 and low fT4 then supports __
true hypothyroidism
79
if you have a low TT4 and a normal fT4 by ED then supports __
euythyroid sick syndrome/ non-thyroidal illness
80
how should TSH concentration be in does with nonthyroidal illness
normal
81
how should TSH be in dogs with primary hypothyroidism
high
82
dogs with secondary or tertiary hypothyroidism should have __TSH
low
83
if a patient has a low TT$ and high TSH then dx__
primary hypothyroidism
84
if patient has low TT4 and normal TSH what can you conclude
1. Can’t exclude hypothyroidism if clinical and other lab signs
2. Can’t rule out nonthyroidal illness or drugs
85
what is gold standard for definitive dx for thyroid dysfunction
TSH stimulation test
86
what is one exception to ruling out hypothyroidism in a dog with a normal TT4
TT4 can sometimes be high in dogs with hypothyroidism due to false increase caused by interference by T4 autoantibodies
87
88
what is most common causes of hyperthyroidism in cats
hyperplasia or benign adenoma
89
are majority of thyroid tumors in dogs benign or malignant
malignant
90
are thyroid tumors in dogs functional or non-functional
non-functional
91
what are some clinical signs of hyperthyroidism in cats
weight loss, polyphagia, vomiting, diarrhea, hyperactivity
92
what are some PE findings for hyperthyroidism in cats
1. Palpable goiter
2. Muscle wasting
3, less common: heart murmur, tachycardia, hypertension
93
what are some common CBC findings in cats with hyperthyroidism
erythrocytosis
94
what is common finding on serum biochemistry in cats with hyperthyroidism
increase ALT, AST, ALP
95
what lab test is able to dx feline hyperthyroidism
total t4
96
if you have clinical signs of hyperthyroidism, __ and __ is increased then consisten t with hyperthyroidism
thyroid slips increase TT4
97
what do you do in cats where you suspect hyperthyroidism but total T4 is in upper half of reference interval
1. Repeat TT4
2. Free T4 by ED measurement
3. TSH measurement
4. Thyroid scintigraphy
98
if TT4 and fT4 is increase in cat then dx__
hyperthryoidism
99
if TT4 is in upper half of RI and fT4 is increased in cat then dx __
hyperthryoidism
100
if TT4 is in upper half of RI and fT4 is normal in cat then __
rule out hyperthyroidism
