A 40-year-old man comes to the office for a medical evaluation. He has not seen a physician for many years and his wife insisted he get "checked out." The patient has no prior medical conditions but says that lately he has been feeling fatigued and has had occasional muscle aches. He has also gained 4.5 kg (9.9 lb) over the past year. The patient does not smoke but occasionally drinks alcohol. Family history is significant for coronary artery disease in the patient's father. Blood pressure is 130/92 mm Hg and pulse is 60/min. BMI is 26 kg/m². Physical examination shows no abnormalities. Fasting serum lipid results are as follows: Which of the following is the best next step in management of this patient's dyslipidemia?

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This patient has fatigue, weight gain, and mild diastolic hypertension, which together suggest hypothyroidism. Hypothyroidism is associated with potential lipid abnormalities that can lead to increased risk of coronary atherosclerosis. Hypothyroidism causes decreased LDL turnover, largely due to decreased expression and activity of LDL receptors, leading to elevated circulating levels of total cholesterol and LDL. It also causes decreased activity of lipoprotein lipase, leading to hypertriglyceridemia (pure hypertriglyceridemia without hypercholesterolemia is uncommon). Patients with hypercholesterolemia should have a serum TSH measurement to screen for underlying hypothyroidism. If not already done, TSH should also be checked prior to initiation of statin medications (eg, atorvastatin) because untreated hypothyroidism can increase the risk of statin myopathy, and initiation of statins can cause worsening of concurrent hypothyroid myopathy (as in this patient with myalgias) (Choice A). Treatment of hypothyroidism with levothyroxine can improve lipid levels, although normalization may take several months. (Choice B) Exogenous androgen use is associated with increased (or occasionally decreased) levels of total cholesterol and LDL and decreased HDL. However, it is not associated with hypertriglyceridemia. (Choice D) Adding ezetimibe to a statin may slightly lower the risk of cardiovascular events for patients with established atherosclerosis; benefits in primary prevention are less clear. Regardless, statins are first-line therapy for almost all patients. (Choice E) Fibrates (eg, gemfibrozil) can reduce the risk of pancreatitis due to very high triglyceride levels (eg, >1000 mg/dL) but have little benefit in cardiovascular prevention. Statins reduce the risk of heart disease and also lower triglyceride levels, and are preferred for mild to moderate hypertriglyceridemia (150-500 mg/dL). For this patient, treatment of the underlying hypothyroidism may normalize his serum triglycerides. (Choice F) LDL receptor mutations are seen in some patients with familial hypercholesterolemia (FH). This disorder is characterized by LDL >190 mg/dL (homozygotes can have LDL >500 mg/dL), as well as cutaneous xanthomas and typically a strong family history of premature atherosclerosis, not seen in this patient. In addition, even when FH is suspected, most patients are first treated empirically with statins (ie, without genetic testing). Educational objective: Hypothyroidism can cause elevated levels of total cholesterol, LDL, and triglycerides and is associated with an increased risk of coronary atherosclerosis. Treatment of hypothyroidism with levothyroxine can improve lipid levels, although normalization may take several months. References: The lipid-lowering effect of levothyroxine in patients with subclinical hypothyroidism: a systematic review and meta-analysis of randomized controlled trials. (http://www.ncbi.nlm.nih.gov/pubmed/28342184) Direct effects of thyroid hormones on hepatic lipid metabolism. (http://www.ncbi.nlm.nih.gov/pubmed/29472712)

A 40-Year-Old Man Comes to the Office for a Medical