A 48-year-old woman comes to the office for evaluation of elevated blood pressure, which was first noted at her dentist's office 4 weeks ago. Repeated home blood pressure measurements since then have remained around 150/90 mm Hg. The patient has had no symptoms and has no history of hypertension or other medical conditions. She takes no medications and does not use tobacco, alcohol, or illicit drugs. Family history is significant for hypertension in her father. Blood pressure is 152/88 mm Hg and pulse is 76/min. A repeat blood pressure measurement after 15 minutes shows a similar reading. BMI is 28.6 kg/m2. Physical examination reveals clear lungs, normal heart sounds, a nontender abdomen with no organomegaly, and no lower extremity edema. There are no abnormalities on ECG. Laboratory testing shows normal serum electrolytes and creatinine and no proteinuria. Which of the following additional evaluations is most appropriate in this patient?
Laboratory evaluation of hypertension | |
Renal function tests |
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Endocrine tests |
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Cardiac tests |
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Other tests |
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This patient has hypertension, defined as a sustained blood pressure ≥130 mm Hg systolic or ≥80 mm Hg diastolic (some guidelines recommend ≥140/90 mm Hg for diagnosis); given her age, mildly elevated blood pressure, and family history of hypertension, this most likely represents primary (essential) hypertension. The initial evaluation should identify complications of hypertension (eg, chronic kidney disease) or comorbid conditions (eg, hyperlipidemia) that might influence management. Assessment should include a serum chemistry panel (including electrolytes and creatinine), hemoglobin/hematocrit, lipid panel, and urinalysis.
In addition, patients with hypertension should be screened for diabetes mellitus with either fasting blood glucose, which can be obtained as part of a serum chemistry panel, or hemoglobin A1c. Even in the absence of hypertension, screening is advised for patients age 35-70 with a BMI ≥25 kg/m2 (ie, overweight or obesity). Screening at younger ages should be considered for those with additional risk factors (eg, family history of diabetes).
(Choice A) Many experts recommend ECG to identify signs of left ventricular hypertrophy in patients with hypertension. Further assessment of ventricular function with echocardiography is more specific but is expensive and would have low yield in this young patient with mild hypertension and a normal ECG.
(Choice B) Testing for sleep apnea is indicated for patients with symptoms (eg, daytime somnolence, witnessed apneic episodes) and can be considered for those with refractory hypertension. However, it is not indicated for asymptomatic patients with uncomplicated hypertension.
(Choice C) Duplex Doppler ultrasonography can identify renal artery stenosis, which typically occurs in older men with diffuse atherosclerosis and causes severe or resistant hypertension requiring ≥3 medications. Other characteristic findings include recurrent flash pulmonary edema and unexplained renal failure after starting an ACE inhibitor.
(Choice D) Plasma renin activity is used to evaluate primary hyperaldosteronism. However, patients typically have severe or resistant hypertension; hypokalemia is common. Primary hyperaldosteronism is unlikely in this patient with mild hypertension and normal serum electrolytes.
Educational objective:
Patients with hypertension should be screened for diabetes mellitus with either fasting blood glucose or hemoglobin A1c. Even in the absence of hypertension, screening for diabetes is advised for patients age 35-70 with a BMI ≥25.