Should We Routinely Measure Renin Levels to Diagnose and Treat Patients With Hypertension? (Part I)

The Argument For

Phyllis August, MD, MPH

In This Article

Measuring Renin in Patients With Resistant Hypertension

Patients with true resistant hypertension should be carefully evaluated for secondary hypertension. Resistant hypertension is rare and is operationally defined as elevated BP despite three antihypertensive agents including a diuretic. For example, a 50-year-old male was referred to the Cornell Hypertension Center for treatment of "resistant hypertension." He had hypertension for 15 years, treated with amlodipine with suboptimal control (150-160/80-90 mm Hg). He had an acute myocardial infarction with a subsequent coronary artery bypass operation. He was treated postoperatively with lisinopril, metoprolol, verapamil, Hyzaar (losartan potassium and hydrochlorothiazide; Merck & Co., Whitehouse Station, NJ) and terazosin and had a BP of 200/110 mm Hg. His serum potassium was 3.8 mEq/L. He was switched from verapamil to amlodipine, and a plasma renin and 24-hour urine aldosterone excretion were measured. His plasma renin was 0.15 ng/mL/h, and his urine aldosterone excretion was 35 µg/d. A computed tomography scan demonstrated an adrenal nodule. Spironolactone 25 mg daily was added to his regimen, and Hyzaar was discontinued. His BP is 120/80 mm Hg and he is considering adrenalectomy. This case illustrates that in cases where secondary hypertension is a consideration, measurement of renin can be invaluable, particularly when mineralocorticoid hypertension is present.