A 50-year-old man is evaluated for poorly controll - highsky

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A 50-year-old man is evaluated for poorly controlled hypertension. His blood pressure has been elevated for 12 years and remains between 150/105 mm Hg and 170/105 mm Hg despite the use of multiple medications. He also has poor exercise tolerance and fatigue and often falls asleep in the afternoon. Medications are atenolol, 50 mg/d; amlodipine, 10 mg/d; and hydrochlorothiazide, 25 mg/d.

On physical examination, blood pressure is 168/110 mm Hg. He is obese and appears plethoric. The remainder of the examination is normal.

Laboratory Studies
Glucose (fasting)

102 mg/dL (5.66 mmol/L)
Blood urea nitrogen

20 mg/dL (7.14 mmol/L)
Creatinine

1.4 mg/dL (123.79 μmol/L)
Sodium

140 meq/L (140 mmol/L)
Potassium

3.9 meq/L (3.9 mmol/L)
Bicarbonate

25 meq/L (25 mmol/L)
Cholesterol

220 mg/dL (5.69 mmol/L)
Triglycerides

190 mg/dL (2.15 mmol/L)
High-density lipoprotein cholesterol

37 mg/dL (0.96 mmol/L)

Which of the following is the most likely cause of this patient's resistant hypertension?

A Renovascular hypertension
B Primary hyperaldosteronism
C Pheochromocytoma
D Type 2 diabetes mellitus
E Sleep apnea syndrome

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ee

[ArchivalUser]

ee?

[ArchivalUser]

e?

[ArchivalUser]

Correct Answer = E)


* Sleep apnea is associated with resistant hypertension and is particularly prevalent in obese patients.
* Hypertension associated with sleep apnea may be related to insulin resistance, increased activity of the sympathetic nervous system, and increased sodium retention.

Sleep apnea syndrome may contribute to resistant hypertension as well as to increased cardiovascular and cerebrovascular disease risk. Affected patients may have excessive fatigue and may fall asleep while driving or working. This condition has a higher prevalence in overweight men. The pathogenesis of sleep apnea syndrome is complex and linked to obesity, insulin resistance, and increased sodium retention. Several studies have shown that patients with sleep apnea syndrome have increased activity of the sympathetic nervous system, which also occurs in obesity. Coexistent insulin resistance and impaired glucose tolerance also may be present in these patients.

Renovascular hypertension may cause resistant hypertension but is less common than sleep apnea. Atherosclerotic renovascular hypertension usually develops in older patients, whereas fibromuscular dysplasia often presents in younger patients and is more common in women. Primary aldosteronism may be present in as many as 10% of patients with resistant hypertension and is included in the differential diagnosis. However, this condition is less likely in a patient who takes hydrochlorothiazide and has a normal potassium level.

Pheochromocytoma is a rare form of hypertension mediated by excess catecholamines. This condition causes palpitations, diaphoresis, tremor, flushing, and headaches. Diagnosis of pheochromocytoma may be difficult, and the clinical manifestations vary significantly. This patient's presentation is consistent with this condition, but sleep apnea is more likely because it is more common and more likely to be associated with obesity. This patient is at risk for type 2 diabetes mellitus, but his fasting glucose level does not meet the criteria for diabetes. Diabetes is associated with hypertension but is not considered a cause of resistant hypertension.
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