Endocrine Weight Loss Endocrine Disorders 4 — Questions and Answers
Question 1: Which peptide hormone secreted by L-cells of the gut inhibits glucagon, slows gastric emptying, and promotes satiety?
- Gastric inhibitory peptide (GIP)
- Glucagon-like peptide-1 (GLP-1) (Correct answer)
- Cholecystokinin (CCK)
- Peptide YY (PYY)
Correct answer: Glucagon-like peptide-1 (GLP-1)
GLP-1 is an incretin hormone that stimulates insulin release, suppresses glucagon, slows gastric emptying, and signals fullness to the brain.
Question 2: A patient with obesity has elevated fasting insulin but normal fasting glucose. This pattern most likely indicates:
- Type 1 diabetes mellitus
- Insulinoma
- Compensated insulin resistance (prediabetes risk) (Correct answer)
- Adrenal insufficiency
Correct answer: Compensated insulin resistance (prediabetes risk)
Elevated fasting insulin with normal glucose reflects compensated insulin resistance, where the pancreas over-secretes insulin to maintain euglycemia.
Question 3: Which thyroid condition causes weight loss, heat intolerance, tremor, and tachycardia due to excess thyroid hormone?
- Hashimoto's thyroiditis
- Hypothyroidism
- Hyperthyroidism (thyrotoxicosis) (Correct answer)
- Thyroid nodule
Correct answer: Hyperthyroidism (thyrotoxicosis)
Hyperthyroidism causes excess T3/T4, elevating basal metabolic rate and producing weight loss, heat intolerance, sweating, tremor, and palpitations.
Question 4: Which genetic syndrome causing obesity is characterized by hyperphagia, hypogonadism, short stature, and intellectual disability due to a chromosome 15 defect?
- Turner syndrome
- Prader-Willi syndrome (Correct answer)
- Bardet-Biedl syndrome
- Alström syndrome
Correct answer: Prader-Willi syndrome
Prader-Willi syndrome results from loss of paternal chromosome 15q11-13 genes, causing extreme hyperphagia and severe obesity starting in childhood.
Question 5: The dexamethasone suppression test is used to screen for which endocrine disorder?
- Hypothyroidism
- Cushing's syndrome (Correct answer)
- Primary hyperaldosteronism
- Acromegaly
Correct answer: Cushing's syndrome
In the overnight 1 mg dexamethasone suppression test, failure to suppress morning cortisol below 1.8 mcg/dL suggests Cushing's syndrome.
Question 6: Which hormone secreted by the stomach rises before meals and falls after eating, driving hunger?
- Leptin
- Insulin
- Ghrelin (Correct answer)
- Glucagon
Correct answer: Ghrelin
Ghrelin is the primary orexigenic (appetite-stimulating) hormone, secreted by gastric fundus cells; levels surge before meals and drop postprandially.
Question 7: A patient on long-term glucocorticoid therapy for rheumatoid arthritis gains 15 lbs over 6 months. The weight gain is primarily attributed to:
- Increased thyroid hormone production
- Cortisol-induced appetite stimulation and lipogenesis promoting central fat deposition (Correct answer)
- Reduced renal sodium excretion only
- Decreased insulin secretion
Correct answer: Cortisol-induced appetite stimulation and lipogenesis promoting central fat deposition
Exogenous glucocorticoids mimic Cushing's syndrome, stimulating appetite, promoting visceral lipogenesis, and redistributing fat to central depots.
Endocrine Weight Loss Endocrine Disorders 4
Which peptide hormone secreted by L-cells of the gut inhibits glucagon, slows gastric emptying, and promotes satiety?