A 45-year-old man comes to the office due to several abnormal blood pressure readings over the past year. He also has had fatigue, which he attributes to stress at work. The patient is a carpenter, and his diet consists primarily of fast food several times a day because he is busy with worksite jobs. He wakes up several times at night and occasionally finds it difficult to fall back asleep. He has had no chest pain, shortness of breath, light-headedness, or syncope. Family history is negative for hypertension, stroke, and early-onset coronary artery disease. The patient drinks 2 beers a day on weekends. Blood pressure is 151/90 mm Hg on the right arm and 159/95 mm Hg on the left. Repeat blood pressure on the left arm is 158/94 mm Hg. Pulse is 78/min and regular. BMI is 32 kg/m². Physical examination is unremarkable. ECG shows normal sinus rhythm with no abnormalities. Serum chemistry panel and TSH are within normal limits. Which of the following is the most likely underlying cause of this patient's hypertension?

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11ec25c8_d24c_381c_bc81_998d0dde3a7e_MD0003_00 This patient with hypertension has obesity, nocturnal awakenings, and daytime fatigue, consistent with obstructive sleep apnea (OSA). Men with obesity are at greatest risk. In OSA, upper airway obstruction (due to pharyngeal muscle relaxation during sleep) causes progressive hypoxia and hypercapnia until chemoreceptors in the carotid body and brainstem trigger arousal, which restores pharyngeal tone. Manifestations usually include nocturnal awakenings, daytime fatigue, and reports of loud snoring and apneic episodes from sleeping partners. Patients commonly report difficulty maintaining or falling back to sleep. Because nighttime apneic episodes trigger a strong catecholamine response, many (~50%) patients with OSA develop secondary hypertension. Although the hypertension is often recalcitrant to antihypertensive medications, it generally improves or resolves with treatment of the underlying OSA (eg, nighttime continuous positive airway pressure). Other cardiovascular conditions frequently triggered by OSA include pulmonary hypertension, right-sided heart failure, coronary heart disease, and arrhythmias (eg, atrial fibrillation). (Choice A) Heavy drinking (≥5 drinks in a single sitting) can cause hypertension. However, intermittent, moderate intake (≤1 drink a day for women, ≤2 for men) does not seem to significantly increase risk. This patient drinks only 2 beers daily on weekends; it is unlikely that alcohol caused his hypertension. (Choice B) Generalized anxiety disorder can increase the risk of hypertension, but this patient's nocturnal awakenings, daytime fatigue, and underlying obesity are more suggestive of OSA. (Choice D) Primary hyperaldosteronism should be suspected in patients with hypertension associated with hypokalemia (either at baseline or after initiation of low-dose diuretic therapy). Disrupted sleep is not a typical feature. (Choice E) Renovascular hypertension is generally suspected in those with widespread atherosclerosis, abdominal bruit, new-onset hypertension at an advanced age, acute kidney injury after initiation of an ACE inhibitor, or recurrent flash pulmonary edema/resistant heart failure. Educational objective: Obstructive sleep apnea (OSA) is a common cause of secondary hypertension due to the production of catecholamines during apneic episodes. The hypertension is often resistant to medications, but treatment of the underlying OSA (eg, nocturnal continuous positive airway pressure) often leads to resolution. Other cardiovascular complications of OSA include pulmonary hypertension, right-sided heart failure, coronary heart disease, and arrhythmias.

A 45-Year-Old Man Comes to the Office Due to Several