A 42-year-old man comes to the clinic for follow-up of poorly controlled hypertension. He is currently taking maximum doses of amlodipine and doxazosin. He occasionally experiences muscle weakness and cramps. His blood pressure is 164/100 mm Hg. Physical examination is otherwise unremarkable.
Laboratory studies show:
| Test | Result | Reference Range |
|---|---|---|
| Sodium | 146 mEq/L | 136-145 mEq/L |
| Potassium | 2.8 mEq/L | 3.5-5.0 mEq/L |
| Chloride | 103 mEq/L | 98-106 mEq/L |
| Bicarbonate | 31 mEq/L | 22-28 mEq/L |
| Blood urea nitrogen | 14 mg/dL | 8-20 mg/dL |
| Creatinine | 0.8 mg/dL | 0.7-1.3 mg/dL |
Based on the interpretation of these laboratory results, which of the following hormone profiles is most likely in this patient?
- Elevated plasma aldosterone concentration and suppressed plasma renin activityCevap
- BElevated plasma aldosterone concentration and elevated plasma renin activity
- CSuppressed plasma aldosterone concentration and suppressed plasma renin activity
- DSuppressed plasma aldosterone concentration and elevated plasma renin activity
- ENormal plasma aldosterone concentration and normal plasma renin activity
Cevap
Elevated plasma aldosterone concentration and suppressed plasma renin activity
The correct answer accurately describes the pathophysiology of primary hyperaldosteronism (Conn syndrome). This condition presents classically with hypertension, hypokalemia, and metabolic alkalosis. The autonomous, unregulated secretion of aldosterone from the adrenal gland causes renal sodium retention (leading to volume expansion and hypertension) and simultaneous excretion of potassium and hydrogen ions (leading to hypokalemia and metabolic alkalosis). The resulting volume expansion suppresses the release of renin via the negative feedback mechanism, resulting in a low or suppressed plasma renin activity.
Adım Adım Çözüm
Anahtar Kavram
Patients with resistant hypertension accompanied by hypokalemia and metabolic alkalosis should be suspected of having primary hyperaldosteronism, characterized by elevated plasma aldosterone and suppressed plasma renin activity.