WBR0210

Author	PageAuthor::Vendhan Ramanujam
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Inpatient Facilities
Sub Category	SubCategory::Endocrine, SubCategory::Endocrine
Prompt	[[Prompt::A 62 year old male is hospitalized following acute myocardial infarction. His other medical problems include type 2 diabetes mellitus, hypertension, emphysema and degenerative joint disease. He admits smoking two packs of cigarettes daily as well as drinking two bottles of beer daily for the past 20 years. His medications include aspirin, glyburide, metoprolol, enalapril, heparin, albuterol and ipratropium inhalers. His blood pressure is 150/90 mm Hg, pulse 86/min, respiratory rate 16/min and temperature is 36.6 C (98 F). During his stay in the hospital, a number of blood tests were ordered including a thyroid function test. Which of the following lab abnormalities is an indication for a thyroid function test in this patient?]]
Answer A	AnswerA::Unexplained hypocalcemia
Answer A Explanation	[[AnswerAExp::Incorrect-Hypocalcemia is not seen in hypothyroid patients.]]
Answer B	AnswerB::Hyperlipidemia
Answer B Explanation	[[AnswerBExp::Correct-Hyperlipidemia is one among the indications for thyroid function test in hypothyroid patients. The most common lipid abnormality seen in hypothyroid patients is increased LDL. Hypercholesterolemia combined with hypertriglyceridemia can sometimes occur. The reason for increased LDL is decreased LDL clearance following decreased LDL receptors due to thyroid hormone deficiency. Thyroid hormones mediate the production of LDL receptors.]]
Answer C	AnswerC::Thrombocytopenia
Answer C Explanation	[[AnswerCExp::Incorrect-Thrombocytopenia is not seen in hypothyroid patients.]]
Answer D	AnswerD::Neutropenia
Answer D Explanation	[[AnswerDExp::Incorrect-Neutropenia is not seen in hypothyroid patients.]]
Answer E	AnswerE::Unexplained hypernatremia
Answer E Explanation	[[AnswerEExp::Incorrect-Only unexplained hyponatremia is an indication of thyroid function test because it may occur due to inappropriate ADH secretion in hypothyroid patients. Hypernatremia is not seen in hypothyroid patients.]]
Right Answer	RightAnswer::B
Explanation	[[Explanation::Hyperlipidemia is an indication for thyroid function test, because it occurs with increased frequency in hypothyroid patients. The most common lipid abnormality seen in hypothyroid patients is increased LDL. Hypercholesterolemia combined with hypertriglyceridemia can sometimes occur. The reason for increased LDL is decreased LDL clearance following a decrease in LDL receptors due to deficiency in thyroid hormones. Thyroid hormones mediate the production of LDL receptors. Lipid abnormalities might take months to resolve despite adequate hypothyroid treatment and caution must be exercised in patients with poorly controlled hypothyroidism because of an increased risk of myopathy with statin use. Educational objective: Hyperlipidemia, unexplained hyponatremia and elevated serum muscle enzymes are indications of thyroid function test. Educational Objective: References: ]]
Approved	Approved::Yes
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