Endocrinology- Concepts Flashcards
Thyroid illness
hyperthyroidism
hypothyroidism
goitre
carcinoma thyroid
pancreas illnesses
type 1 diabetes
type 2 diabetes
kidney illness
renin depended hypertension
testes illness
subfertility
testicular failure
bone illness
osteoporosis
osteomalacia
pituitary and hypothalamus illnesses
- hyperprolactinaemia
- hypopituitarism
- pituitary tumors
parathyroid glands illness
- hyperparathyroidism
- hypoparathyroidism
breast illness
- hyperprolactinaemia
adrenals illness
addison’s disease
cushing syndrome
conn syndrome
phaechromocytoma
ovaries illness
polycystic ovary syndrome (PCOS)
menopause
subfertility
What are the main causes of endocrine gland hyperfunction?
Neoplastic: Tumors causing overproduction of hormones.
Autoimmune: Conditions where the immune system stimulates excessive hormone production.
Iatrogenic: Hormone excess due to medical treatments, such as excessive hormone therapy.
What are the main causes of endocrine gland hypofunction?
Infectious/Inflammatory: Infections or chronic inflammation leading to gland destruction and reduced hormone production.
What causes hormone resistance in endocrine dysfunction?
Receptor mutations: Mutations in hormone receptors can prevent proper hormone action.
Enzyme defects:
Deficiencies in enzymes required for hormone action can lead to resistance
What is Cushing’s syndrome?
Cushing’s syndrome is a condition caused by prolonged exposure to elevated levels of cortisol, often due to pituitary adenomas, adrenal tumors, or ectopic ACTH production.
What are the common causes of Cushing’s syndrome
Pituitary adenomas (Cushing’s disease): Benign tumors producing excess ACTH.
Adrenal tumors: Primary adrenal tumors producing cortisol.
Ectopic ACTH syndrome: Tumors outside the pituitary producing ACTH (e.g., small cell lung cancer).
Iatrogenic: Prolonged use of corticosteroid medications.
What are the classic symptoms of Cushing’s syndrome?
Weight gain (central obesity)
Moon facies (rounded face)
Buffalo hump (fat accumulation on the upper back)
Skin changes (thin, easy bruising)
Muscle weakness
Hypertension
Hyperglycemia (high blood sugar)
How is Cushing’s syndrome diagnosed?
24-hour urinary free cortisol test: Measures cortisol levels in urine.
Low-dose dexamethasone suppression test: Assesses cortisol suppression response.
Late-night salivary cortisol test: Measures cortisol levels at night, which should normally be low.
What are the potential complications of Cushing’s syndrome?
Complications may include:
Osteoporosis and increased fracture risk
Cardiovascular disease (hypertension, dyslipidemia)
Diabetes or glucose intolerance
Increased risk of infections
Psychiatric issues (depression, anxiety)
How is Cushing’s syndrome treated?
Surgery: Removal of the tumor (pituitary or adrenal).
Medications: Drugs to inhibit cortisol production (e.g., ketoconazole, mitotane).
Radiation therapy: For pituitary tumors when surgery is not an option.
Cushing’s discriminating features
Skin:
- Easy Bruising
- Thin skin
- Facial plethora
- Typical striae (purple, > 1cm wide)
Muscle:
- Proximal weakness
Growth
- Short stature in children
What is pseudo-Cushing’s syndrome?
Pseudo-Cushing’s syndrome is a condition that mimics Cushing’s syndrome, characterized by elevated cortisol levels due to non-endocrine factors, such as stress, depression, or excessive alcohol consumption, rather than an adrenal or pituitary disorder.
How does alcohol consumption contribute to pseudo-Cushing’s syndrome?
Chronic alcohol use can lead to increased cortisol production, causing symptoms similar to Cushing’s syndrome, such as weight gain, facial changes, and skin alterations. It may also cause stress on the body, further elevating cortisol levels.
How does depression affect cortisol levels in pseudo-Cushing’s syndrome?
Depression is associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to elevated cortisol levels. Symptoms may mimic those of Cushing’s syndrome, including fatigue, weight changes, and mood disturbances.
How can pseudo-Cushing’s syndrome be differentiated from true Cushing’s syndrome?
Pseudo-Cushing’s syndrome is typically characterized by:
Cortisol levels: While cortisol may be elevated, it often does not exhibit the same suppression response to dexamethasone as seen in true Cushing’s syndrome.
Reversible symptoms: Symptoms related to pseudo-Cushing’s usually improve with treatment of the underlying cause, such as reducing alcohol intake or addressing depression.
What is a pheochromocytoma?
A pheochromocytoma is a rare tumor of the adrenal gland that secretes catecholamines (e.g., epinephrine, norepinephrine), leading to episodes of hypertension and other symptoms.
How might pheochromocytoma be suspected in a patient with resistant hypertension?
Pheochromocytoma should be considered in cases of resistant hypertension, particularly if the hypertension is difficult to control despite multiple medications.
Is routine screening justified for pheochromocytoma?
Routine screening is not justified for the general population, but it is recommended for individuals with resistant hypertension, especially if there are clinical signs or a family history of endocrine tumors.
What symptoms should be asked about when evaluating for pheochromocytoma?
Headaches
Sweating
Tachycardia (rapid heart rate)
“Spells” or paroxysmal episodes of elevated blood pressure (occurring in approximately 50% of cases).
What family history should be considered when evaluating for pheochromocytoma?
A family history of conditions associated with pheochromocytoma, such as multiple endocrine neoplasia (MEN) syndromes, especially MEN2, or a family history of pheochromocytomas themselves, should be assessed.
What is an adrenal incidentaloma, and how should it be managed?
An adrenal incidentaloma is an adrenal mass discovered incidentally on imaging studies. It is important to always screen for hormonal activity, including assessment for pheochromocytoma, cortisol excess, and aldosterone excess, regardless of size
Hirsutism differential diagnosis
PCOS
Familial
Idiopathic
What is Polycystic Ovary Syndrome (PCOS)?
PCOS is a common hormonal disorder affecting people with ovaries, characterized by irregular menstrual cycles, excess androgen levels, and polycystic ovaries.
What are the common symptoms of PCOS?
Irregular or absent menstrual periods
Excess hair growth (hirsutism)
Acne and oily skin
Weight gain or obesity
Thinning hair or male-pattern baldness
Infertility
What are the diagnostic criteria for PCOS?
The diagnosis of PCOS typically requires at least two of the following three criteria (Rotterdam criteria):
Irregular or absent ovulation (irregular menstrual cycles).
Clinical and/or biochemical signs of hyperandrogenism (e.g., hirsutism, elevated testosterone levels).
Polycystic ovaries visible on ultrasound.
What are the potential complications associated with PCOS?
Infertility
Type 2 diabetes and insulin resistance
Endometrial hyperplasia and cancer
Cardiovascular disease
Sleep apnea
Depression and anxiety
What are the treatment options for PCOS?
- Lifestyle modifications: Weight loss through diet and exercise.
- Hormonal contraceptives: To regulate menstrual cycles and reduce androgen levels.
- Anti-androgens: Such as spironolactone for hirsutism and acne.
- Fertility treatments: Such as clomiphene citrate or letrozole for those seeking pregnancy.
- Metformin: To improve insulin sensitivity.
What lifestyle changes can help manage PCOS symptoms?
- Maintaining a healthy weight
- Following a balanced diet low in refined carbohydrates
- Engaging in regular physical activity (e.g., aerobic exercise, strength training)
- Managing stress through relaxation techniques or counseling
What is hirsutism?
Hirsutism is a condition characterized by excessive hair growth in women in areas typically associated with male-pattern hair distribution, such as the face, chest, and back.
What are the common causes of hirsutism?
- Polycystic Ovary Syndrome (PCOS): The most common cause.
- Hormonal imbalances: Excess androgens from conditions like adrenal hyperplasia or tumors.
- Medications: Certain drugs like anabolic steroids or hormonal treatments.
- Genetics: Family history of hirsutism can play a role.
How is hirsutism diagnosed?
Clinical assessment of hair growth patterns using the Ferriman-Gallwey scoring system.
Evaluation of underlying causes through medical history, physical examination, and laboratory tests (e.g., hormone levels).
What are the treatment options for managing hirsutism?
- Hormonal contraceptives: To reduce androgen levels.
- Anti-androgens: Such as spironolactone or finasteride.
- Topical treatments: Eflornithine cream for facial hair.
- Hair removal methods: Such as laser therapy, electrolysis, or waxing.
What does the guideline suggest regarding testing for elevated androgen levels in women with isolated mild hirsutism?
The guideline suggests against testing for elevated androgen levels in women with isolated mild hirsutism, as the likelihood of identifying a medical disorder that would change management or outcome is low (2QEEE).
Under what conditions should elevated androgen levels be tested in women with hirsutism?
Moderate or severe hirsutism.
Any degree of hirsutism that is sudden in onset, rapidly progressive, or associated with any of the following:
Menstrual irregularity or infertility
Central obesity
Acanthosis nigricans
Rapid progression
Clitoromegaly (2QEEE).
What are the vascular causes of erectile dysfunction?
Vascular causes include reduced blood flow to the penis due to conditions such as atherosclerosis, hypertension, and other cardiovascular diseases. Endothelial dysfunction can also impair vasodilation, contributing to erectile dysfunction.
What are the neurologic causes of erectile dysfunction?
Neurologic causes include nerve damage from conditions such as diabetes, multiple sclerosis, spinal cord injuries, or pelvic surgeries. These can disrupt the nerve signals necessary for achieving and maintaining an erection.
What are local penile (cavernosal) factors that can lead to erectile dysfunction?
Peyronie’s disease (curvature of the penis due to fibrous plaque)
Vascular problems specifically affecting the penile arteries
Injury to the penis or surrounding tissues
What hormonal imbalances can contribute to erectile dysfunction?
Hormonal causes include low testosterone levels (hypogonadism), elevated prolactin levels, and thyroid dysfunction (both hyperthyroidis
What types of medications can induce erectile dysfunction?
Antihypertensives (e.g., beta-blockers, diuretics)
Antidepressants (especially SSRIs)
Antiandrogens
Recreational drugs (e.g., alcohol, opioids)
Certain medications for prostate conditions
What are psychogenic causes of erectile dysfunction?
- Anxiety or stress related to performance
- Depression
- Relationship issues
- Past trauma or negative experiences related to sex
Symptoms and signs suggestive of androgen deficiency in men
- Incomplete or delayed sexual development, eunuchoidism
- reduced sexual desire (libido) and activity
- decreased spontaneous erections
- breast discomfort, gynecomastia
- loss of body (Axillary and pubic) hair, reduced shaving
- very small (especially <5 ml) or shrinking testes
- inability to father children, low or zero sperm count
- height loss, low trauma fracture, low bone mineral density
- hot flushes, sweats
- decreased energy, motivation, initiative and self confidence
- feeling sad or blue, depressed mood, dysthymia
-poor concentration and memory - sleep disturbance, increased sleepiness
- mild anemia (normochromic, normocytic, in the female range)
- reduced muscle bulk and strength
- diminished physical or work performance
- increased body fat, body mass index
What is the recommendation for diagnosing androgen deficiency in men?
Androgen deficiency should only be diagnosed in men who exhibit consistent symptoms and signs, along with unequivocally low serum testosterone levels (1|⊕○○○).
When should clinicians measure serum testosterone levels?
Clinicians should measure serum testosterone levels in patients with clinical manifestations associated with androgen deficiency
What conditions warrant screening for testosterone deficiency?
- Diseases of the sellar region (e.g., pituitary tumors)
- Use of medications affecting testosterone production (e.g., high-dose glucocorticoids, sustained-release opioids)
- HIV-associated weight loss
- End-stage renal disease and maintenance hemodialysis
- Moderate-to-severe chronic obstructive lung disease (COPD)
- Infertility
- Osteoporosis or low-trauma fractures, especially in young men
- Type 2 diabetes mellitus
What are Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH)?
LH and FSH are glycoprotein hormones produced by the anterior pituitary gland. They play crucial roles in regulating the reproductive system in both males and females.
What is the function of Luteinizing Hormone (LH) in females?
In females, LH triggers ovulation and stimulates the formation of the corpus luteum, which produces progesterone necessary for maintaining pregnancy.
What is the function of Follicle-Stimulating Hormone (FSH) in females?
FSH promotes the growth and maturation of ovarian follicles and stimulates the production of estrogen by the ovaries.
What is the function of Luteinizing Hormone (LH) in males?
In males, LH stimulates the Leydig cells in the testes to produce testosterone, which is essential for sperm production and male secondary sexual characteristics.
What is the function of Follicle-Stimulating Hormone (FSH) in males?
FSH acts on the Sertoli cells in the testes to support spermatogenesis and the production of sperm.
How are LH and FSH regulated?
LH and FSH secretion is regulated by Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus. Their levels are also influenced by sex steroids (estrogen and testosterone) through negative feedback mechanisms.
What is the clinical significance of measuring LH and FSH levels?
Measuring LH and FSH levels helps diagnose reproductive disorders, including hypogonadism, polycystic ovary syndrome (PCOS), and pituitary dysfunction. Abnormal levels can indicate issues with the hypothalamus, pituitary gland, or gonads.
What is the initial evaluation for suspected hypogonadism?
The initial evaluation includes a thorough medical history, physical examination, and assessment of symptoms related to low testosterone, such as decreased libido, erectile dysfunction, fatigue, and loss of muscle mass.
How is hypogonadism diagnosed through hormone testing?
Hypogonadism is diagnosed by measuring serum testosterone levels. This should be done in the morning (preferably between 8 AM and 10 AM) when testosterone levels are at their peak.
When should confirmatory testing for testosterone levels be conducted?
Confirmatory testing should be done if the initial testosterone level is low. A second serum testosterone test should be conducted to confirm low levels before making a diagnosis of hypogonadism.
Why are LH and FSH levels measured in the evaluation of hypogonadism?
Measuring LH and FSH levels helps determine whether hypogonadism is primary (testicular failure) or secondary (pituitary or hypothalamic dysfunction). Elevated LH and FSH suggest primary hypogonadism, while low or normal levels indicate secondary causes.
What additional tests may be performed in the evaluation of hypogonadism?
- Prolactin levels to check for prolactinomas
- Thyroid function tests to rule out thyroid disorders
- MRI of the pituitary gland if a pituitary disorder is suspected
- Semen analysis if infertility is a concern
What clinical considerations should be taken into account when testing for hypogonadism?
Consider factors such as age, time of day for testing, the presence of symptoms, and any medications that may affect testosterone levels. Certain conditions like obesity, diabetes, and chronic illnesses may also influence results.
Consequences to age related fall in testosterones
Reduced:
Hb
Bone mineral density
Muscle mass
General Health
More:
IR, metabolic syndrome
Will the elderly benefit from testo replacement
Remains controversial
Adverse effects:
Coronary artery plaque, serum lipids
? CVD risk
Erythrocytosis
Prostate effects
Sleep apnoea
When o we treat hypogonadism
ROUTINE THERAPY NOT INDICATED; INDIVIDUALIZE
Risks vs benefits discussed
ONLY treat if benefits> risks
ONLY treat if testo < 7.0 nmol/L (unequivocally low)
What is acromegaly?
Acromegaly is a hormonal disorder that occurs when the pituitary gland produces excess growth hormone (GH), typically due to a benign tumor called an adenoma. It results in abnormal growth of bones and soft tissues.
What are the common causes of acromegaly?
The most common cause of acromegaly is a growth hormone-secreting pituitary adenoma. Other causes can include ectopic GH secretion from tumors in other parts of the body or, rarely, genetic conditions like multiple endocrine neoplasia type 1 (MEN1).
What are the common symptoms of acromegaly?
Enlarged hands and feet
Facial changes (enlarged nose, jaw, and forehead)
Joint pain
Thickened skin
Sleep apnea
Headaches
Vision problems
How is acromegaly diagnosed?
- Clinical evaluation of symptoms
- Measurement of serum IGF-1 (Insulin-like Growth Factor 1) levels, which are usually elevated
- Oral glucose tolerance test (OGTT), where GH levels do not suppress after glucose administration
- MRI of the pituitary gland to identify adenomas
What are the potential complications of untreated acromegaly?
- Cardiovascular diseases (hypertension, cardiomyopathy)
- Increased risk of type 2 diabetes
- Osteoarthritis
- Sleep apnea
- Increased risk of certain cancers (e.g., colorectal cancer)
What are the treatment options for acromegaly?
Surgical removal of the pituitary adenoma (transsphenoidal surgery)
Medication to reduce GH production (e.g., somatostatin analogs like octreotide, or GH receptor antagonists like pegvisomant)
Radiation therapy if surgery is not successful or feasible
How is acromegaly monitored after treatment?
Patients are monitored through regular measurement of serum IGF-1 levels and GH levels to assess treatment effectiveness. Ongoing assessment of symptoms and complications is also essential.
What is hyperprolactinemia?
Hyperprolactinemia is a condition characterized by elevated levels of prolactin in the blood, which can lead to various reproductive and hormonal disturbances.
What are some physiological causes of hyperprolactinemia?
Pregnancy
Breastfeeding (lactation)
Stress
Sleep (nocturnal elevation of prolactin)
What are some other causes of hyperprolactinemia?
Hypothyroidism
Chronic renal failure
Cirrhosis of the liver
Idiopathic causes
What drugs are commonly associated with hyperprolactinemia?
Antipsychotics (e.g., risperidone, haloperidol)
Antidepressants (e.g., SSRIs)
Anti-nausea medications (e.g., metoclopramide)
Opioids
Estrogen-containing medications
What are the pathologic causes of hyperprolactinemia?
Prolactin-secreting pituitary adenomas (prolactinomas)
Other pituitary tumors
Hypothalamic lesions (e.g., craniopharyngiomas)
Chest wall lesions (e.g., shingles, trauma)
What are the common symptoms of hyperprolactinemia?
Galactorrhea (milk production)
Menstrual irregularities (amenorrhea or oligomenorrhea)
Infertility
Decreased libido
Erectile dysfunction in men
How is hyperprolactinemia diagnosed?
Serum prolactin level measurement (usually in the morning)
Assessing for underlying causes (e.g., thyroid function tests, renal function tests)
MRI of the pituitary gland if a prolactinoma or other pituitary lesion is suspected
What are the treatment options for hyperprolactinemia?
Dopamine agonists (e.g., cabergoline, bromocriptine) to lower prolactin levels and shrink pituitary tumors
Addressing the underlying cause (e.g., adjusting medications, treating hypothyroidism)
Surgery or radiation for resistant or large prolactinomas
: What is short stature?
Short stature is defined as a height significantly below the average for a person’s age and sex, typically below the 3rd percentile or more than 2 standard deviations below the mean height.
What are some common causes of short stature?
Genetic factors (familial short stature)
Constitutional growth delay
Endocrine disorders (e.g., growth hormone deficiency, hypothyroidism)
Chronic illnesses (e.g., celiac disease, renal disease)
Nutritional deficiencies (e.g., malnutrition)
What genetic factors can contribute to short stature?
Turner syndrome
Down syndrome
Achondroplasia and other skeletal dysplasias
Prader-Willi syndrome
Which endocrine disorders are associated with short stature?
Growth hormone deficiency
Hypothyroidism
Cushing’s syndrome
Hyperparathyroidism
How is short stature assessed?
Comprehensive medical history and physical examination
Growth chart analysis to evaluate growth patterns
Laboratory tests (e.g., thyroid function tests, IGF-1 levels, karyotyping)
Bone age assessment via X-ray to determine growth potential
What are the management options for short stature?
Growth hormone therapy for GH deficiency
Treatment of underlying medical conditions (e.g., thyroid hormone replacement)
Nutritional support for deficiencies
Psychological support or counseling for psychosocial issues
Where is testosterone produced?
A. Seminiferous tubules
B. Sertoli cells
C. Gonadotrophin cells
D. Leydig cells
D. Leydig cells
A 41-year-old man presents with recurrent headaches. These usually occur 2-3 times a day and are associated with sweating and palpitations. On presentation is blood pressure in 210/110mmHg.
What would be the diagnostic investigation of choice?
A. Phenoxybenzamine suppression test
B. Abdominal ultrasound
C. 24-hour urinary metanephrine collection
D. 24-hour urinary catecholamine collection
C. 24-hour urinary metanephrine collection
How is Polycystic ovarian syndrome (PCOS) diagnosed?
A. Pelvic ultrasound demonstrating polycystic ovaries
B. Menstrual dysfunction with clinical hyperandrogenism
C. Elevation of the luteal phase androgen
D. Oestrogen level
B. Menstrual dysfunction with clinical hyperandrogenism
A 35-year-old woman presents complaining of fatigue with difficulty climbing stairs and brushing her hair. On examination she has facial plethora, with a dorsocervical fat pad, central obesity and abdominal striae.
What is the most likely diagnosis?
A. Cushing’s syndrome
B. Metabolic syndrome
C. Addison’s Disease
D. Hypothyroidism
A. Cushing’s syndrome
In patients with polycystic ovarian syndrome (PCOS) what should they be screened for?
A. Endometrial cancer
B. Depression
C. Type 2 diabetes
D. Osteoporosis
C. Type 2 diabetes
In screening for acromegaly which of the following investigations is the investigation of choice?
A. Computed tomography of the brain (CTB)
B. Growth hormone suppression test
C. Insulin growth factor 1 (IGF-1)
D. Growth hormone
C. Insulin growth factor 1 (IGF-1)
What is the most common cause of hirsutism?
A. Polycystic ovarian syndrome (PCOS)
B. Congenital adrenal hyperplasia (CAH)
C. Familial causes
D. Ovarian cancer
A. Polycystic ovarian syndrome (PCOS)
What is the majority of total testosterone bound to?
A. Albumin
B. Sex-hormone binding globulin
C. Cholesterol
D. Protein
B. Sex-hormone binding globulin
In the elderly which of the following changes are physiological?
A. Reduced free T4
B. Increased cortisol levels
C. Increased Thyroid-stimulating hormone
D. Increased androgen levels
C. Increased Thyroid-stimulating hormone
A 54-year-old man is investigated for recurrent renal stones. Blood work reveals a high serum parathyroid level.
Which of the following would expect to find regarding the serum calcium and phosphate ions?
A. Calcium normal, phosphate normal
B. Calcium normal, phosphate high
C. Calcium raised; phosphate raised
D. Calcium raised; phosphate low
D. Calcium raised; phosphate low
A 28-year-old woman with primary amenorrhea presents complaining of dizziness and headaches. On examination she has a blood pressure of 174/102mmHg. You notice that she is of short stature, has dysmorphic features and widely spaced nipples with poor breast development.
What is the most likely diagnosis?
A. Turner’s syndrome
B. Noonan’s syndrome
C. Fetal alcohol syndrome
D. Skeletal dysplasia
A. Turner’s syndrome
A 55-year-old man presents with dizzy spells associated with sweating and palpitations. He reports having been diagnosed with hypertension 3 months ago. Despite being on three agents his blood pressure remains uncontrolled.
What is the most likely diagnosis?
A. Pheochromocytoma
B. Atrial Fibrillation
C. Thyrotoxicosis
D. Unstable angina
A. Pheochromocytoma
A 42-year-old man presents complaining of a 3-month history of muscle weakness and headaches. His blood pressure is 176/78mmHg and his examination is unremarkable.
His blood results are as follows:
Sodium- 145
Potassium- 2.8
Bicarbonate - 34
Urea- 4
Creatinine- 72
What is the most appropriate first-line investigation?
A. Computed tomography (CT) abdomen
B. Plasma aldosterone / renin ratio
C. Short synacthen test
D. Adrenal vein sampling
B. Plasma aldosterone / renin ratio
A 29-year-old woman presents complaining of a two-month history of increased fatigue, dizziness and weight-loss. On examination she has a heart rate of 94 beats per minute, and a blood pressure of 86/44mmHg. Her blood results are shown below:
Sodium: 126
Potassium: 5.8
Bicarbonate: 22
Urea: 4
Creatinine: 72
What is the most likely diagnosis?
A. Addison’s Disease
B. Sheehan’s syndrome
C. Pheochromocytoma
D. Nelson syndrome
A. Addison’s Disease
Which hormone stimulates testosterone secretion?
A. Inhibin B
B. Gonadotropin releasing hormone
C. Follicle stimulating hormone
D. Luteinizing hormone
D. Luteinizing hormone
