Endocrinology - MIDTERM Flashcards
T/F Routine thyroid function testing is recommended in asymptomatic patients
False - not recommended (outside of newborn screening)
What medications put a person at risk for thyroid disease?
Lithium
Amiodarone
Risk factors for thyroid disease? What age of women vs men?
- men: age ≥ 60
- women: age ≥ 50
- personal history or strong family history of thyroid disease;
- diagnosis of other autoimmune diseases (T1DM, celiac)
- past history of neck irradiation;
- previous thyroidectomy or radioactive iodine ablation;
- drug therapies such as lithium and amiodarone;
- dietary factors (iodine excess and iodine deficiency in patients from developing countries); or
- certain chromosomal or genetic disorders (e.g., Turner syndrome,3
Down syndrome4
and mitochondrial disease5
-postpartum period
T/F Goitre can occur in either hypo or hyperthyroidism
True
S&S of hypothroidism
- Depression
- Decreased mental function
- ataxia
- Physical tiredness
- Paresthesia
- Hypokinesis
- Hyporeflexia
- Weight gain
- Coarse, dry skin
- Coarseness or loss of hair, inability of hair to hold a curl,
hair loss at eyebrows, and reduced growth of hair.
-reduced growth of nails - Periorbital edema
- Hoarseness
Bradycardia - Isolated diastolic hypertension
Goitre
Diminished sweating - Cold intolerance
Constipation
What is the effect of hypothroidism vs hyperthroidism on menstruation?
Hypo - menorrhagia (heavy bleeding), irregular periods
Hyper - amenorrhea/oligomenorrhea
T/F A TSH value within normal range excludes majority of cases of primary thyroid disorders
True
When do we do an US of the thyroid?
thyroid ultrasound scan is not routinely recommended in patients with abnormal thyroid function tests, unless there
is a palpable abnormality of the thyroid gland
What TSH and fT4 levels would you expect to see in hypothroidism?
High TSH
Low fT4
What TSH and fT4 in hyperthyroidism?
Low TSH
High fT4
Your patient is diagnosed with hypothyroidism and started on medication. How long should you wait before rechecking TSH?
6 weeks (rxfiles says 6-8 weeks)
- also applies for dosage changes
(consider more frequent if pt clinical status changes)
Also need to retest if weight change >20lbs
How does subclinical hypothyroidism look?
Typically asymptomatic or very nonspecific symptoms
Elevated TSH (usually <10mU/L). fT4 normal
Overtreatment with levothyroxine can cause?
atrial fibrillation (more commonly in the elderly) and bone loss in postmenopausal women
+ all other symptoms of hyperthroid
Once TSH has normalized with treatment (euthyroid), it should be checked ____ unless a new indication arises. This confirms adequacy
of treatment dose and compliance with therapy.
Annually
Does the time of day matter when taking thyroid levels?
Yes, TSH levels in the same individual can vary by 50% when measured at different
times of day, with lowest values in the late afternoon and highest values at midnight.
(RxFiles says draw blood in AM)
In individuals with subclinical
hypothyroidism, TSH values can vary by up to 40% even when measured at the same time on different days without indicating
a change in thyroid function. As long as TSH remains within the reference interval, changes over time are not important.
How often do patients on lithium and amiodarone need to have their thyroid function checked?
Lithium: q 6 months
Amio: q 3-6 months
Who is more likely to experience subclinical hypothyroidism?
Women
Advanced age
When do we treat subclinical hypothyroidism?
According to BC guidelines:
is recommended when TSH rises above 10 mU/L
Treatment can be
considered when TSH is between the upper limit of the reference interval but ≤10 mU/L and any of the following are present:
- symptoms suggestive of hypothyroidism
- elevated TPO antibodies
- evidence of atherosclerotic cardiovascular disease, heart failure, or associated risk factors for these diseases; or
- pregnancy
(Rxfiles also says young adults <30yrs)
How often do we monitor patients with subclinical hypothroid who aren’t getting treated?
q 6-12 months or sooner if change in clinical situation
Is hypothyroidism generally considered permanent?
Yes, will usually require lifelong treatment
Most common cause of hypothyroidism?
Hashimotos thyroiditis (autoimmune)
What is a normal TSH level?
0.45 to 4.5mIU/L
TSH Level in hypothyroidism = _____
> 10
TSH levels in subclinical hypothyroidism typically:
4-10 (guidelines vary)
Starting does of levothyroxine? (differentiate healthy young vs older adult vs hypothyroidism)
Young, healthy: use full replacement dose of
1.6-1.7 mcg/kg/d
> 50 years old, or CVD: start at 12.5-25mcg daily ↑ q4-8 wk. If ↑ CVD symptoms, decrease dose
Subclinical: if treating, start at 25-50mcg daily.
What is PCOS? What does PCOS cause?
Dysfunction of the hypothalamic pituitary ovarian axis. Is a syndrome of coexisting conditions:
- excess insulin & androgens
- irregular/ anovulatory menstrual cycle (possible infertility)
- polycystic ovaries
… in people with female sex organs
Risk factors for PCOS
- Irregular ovulation
- Obesity/insulin resistance
- Diabetes (type 1 and 2)
- Hx of premature adenarche (early sexual maturation)
- 1st degree relative with PCOS
- Antiseizure meds (valproate)
When does PCOS typically present?
Clinical manifestations of PCOS usually appear within 2 years of puberty.
May appear after a period of normal menstrual function and pregnancy.
S&S of PCOS
- Hirsutism (dark hair on face, back, etc)
- Alopecia (male pattern)
- Acne (can be severe)
- Hyperhydrosis (excess sweating)
- Acanthosis nigricans.
- Obesity (41%)
- Menstrual disturbances/ Infertility
- Increased insulin
- Increased androgen (testosterone, androstenedione)
Lots of other hormones out of wack (LH, prolactin, DHEA)
20% asymptomatic
What are the possible late sequelae of PCOS (complications)?
Dyslipidemia
DM
CVD, HTN
Endometrial hyperplasia & carcinoma
Criteria for diagnosis of PCOS?
Are differing criteria but Rotterdam criteria from 2003 says must have 2 of 3 of the following:
1) Hyperandrogenism
2) Oligomenorrhea
3) Polycystic ovaries
Another from 2009 states must have hyperandrogenism and either oligomenorrhea or polycystic ovaries
Other tests that may be helpful but are not necessary for diagnosis include measurement of LH and follicle-stimulating hormone (FSH) levels to determine a serum ratio of LH/FSH
Treatment of PCOS (complex but basic idea…)
Depends on whether pt wants to get pregnant or not…
Seems like generally you’re just treating each of the symptoms.
Aggressive lifestyle modification focused on increased physical activity and weight loss is mainstay treatment (weight loss may resolve infertility)
Oral contraceptive pills (OCPs) are the most commonly used treatment for endometrial prevention and
hirsutism
Metformin is used to manage oligomenorrhoea, cause
weight loss, lower insulin levels, and induce ovulation for
women with PCOS:
Acne: topical cream, contraceptives
Spironolactone is used after a four- to six-month oral
contraceptive trial as antiandrogen therapy:
Lots of other complex things that I assume would be managed by a specialist (endo or gyn)
What is addison’s disease
Primary adrenal insufficiency resulting in glucocorticoid
and mineralocorticoid insufficiency.
Chronic form of adrenal gland destruction
What populations are morel likely to get addison’s disease
more common in women and
children
overall very rare - Approximately 40 to 60 cases per million people;
What causes addison’s?
Autoimmune dysfunction of the adrenals accounts for up to 80% of cases (mostly in developed world)
10% to 20% of cases are attributed to TB (spreads to adrenal glands)
Patho of addisons
At least 90% of the adrenal gland is destroyed (only become symptomatic once this extensive destruction)
Reduced levels of aldosterone –> RAAS system affected –> Low Na+ and High K+ , hypovolemia, metabolic acidosis
Reduced cortisol –> low blood gluc in times of stress –> fatigue, weakness
Reduced androgens –> women lose body hair and libido (men not affected because major source of androgens in testes)
Why do we see hyperpigmentation of the skin in addisons?
Pituitary becomes hyperactive to compensate for low cortisol, which results in overproduction of melanocyte stimulating hormone
Where is this hyperpigmentation most visible?
Joints + sun exposed areas
commonly knuckles
S&S of Addison’s disease
Weakness/fatigue
Abdo pain
N/V/D
Anorexia
Weight loss
Hyperpigmentation
Hypoglycemia
Low libido
Salt craving
Muscle & joint pain
Reduced axillary/pubic hair in women
Amenorrhea
Hypotension
Anemia
ECG changes
What is an Addisonian crisis? (acute adrenal crisis)
May be brought on by stressful event (surgery, infection, injury), resulting in sudden need for aldosterone or cortisol
= Medical emergency
S&S of Addisonian crisis
sudden low back,
abdominal, or leg pain
severe vomiting or diarrhea
hypotension
loss of consciousness
Death
Diagnosis of Addisons
Adrenocorticotropic hormone stimulation test: give synthetic ACTH and then measure to see amount of cortisol produced. If low, would indicate adrenal insufficiency (but doesn’t specify if primary or secondary cause).
Need plasma ACTH level to differentiate (will be be high if primary adrenal insufficiency like Addisons)
-Anti-adrenal antibodies (not super useful)
-CT scan of adrenals - can help differentiate if metastatic disease, sarcoidosis, or TB
Treatment for Addisons
*Consult endocrinologist!
Will need hormones:
cortisol (flurocortisone and hydrocortisone) , aldosterone, androgens
- typically taken for rest of life. Otherwise have risk of addisonian crisis
**Need coaching on how to limit risk of infection & what to look for in addisonian crisis
What is Cushing’s syndrome?
= a cluster of symptoms, signs, and
biochemical abnormalities arising from glucocorticoid over-production.
-Key feature is high cortisol and loss of normal feedback control mechanisms
