ODP271 Primary Aldosteronism and Primary Hyperparathyroidism: A Report of Dual Endocrine Hypertension

Background Primary aldosteronism (PA) is one of the common causes of secondary hypertension. Primary hyperparathyroidism (PHPT) is a less common etiology of secondary hypertension. The concomitance of both PA and PHPT is very rare, with a possible bilateral positive feedback loop between the adrenal cortex and the parathyroid gland[1]. Clinical case: A 64-year-old female was referred to the endocrine clinic for secondary hypertension assessment. She was diagnosed with hypertension 30 years earlier, poorly controlled on three antihypertensive medications, nifedipine 90 mg daily, lisinopril 40 mg daily, and atenolol 50 mg daily. She started experiencing muscle cramps two years prior to the referral and was found to be hypokalemic on multiple occasions, with potassium ranging between 2.5 to 3 mmol/L. She also had multiple admissions to the emergency department for hypertensive urgencies within the last year. Family history was positive for poorly controlled hypertension in the patient's mother. Physical examination showed class I obesity with a BMI of 31, but otherwise unremarkable. Workup showed elevated aldosterone concentration of 38 ng/dl and suppressed renin concentration (<1 pg/ml) with an aldosterone/renin ratio of 38. Overnight dexamethasone suppression test was normal (cortisol of 1.5 mcg/dl, suppressed ACTH of 5.5 pg/ml, and appropriately elevated dexamethasone of 324 ng/dl). 24-hour urine metanephrine and normetanephrine levels were normal. Imaging showed bilateral adrenal adenomas of about 13-14 mm in widest diameter, with an average density of 10 Hounsfield units. Adrenal venous sampling revealed hyperfunctioning left adrenal with normal right adrenal. The left adrenal gland was removed laparoscopically, and blood pressure normalized postoperatively on the single antihypertensive agent (lisinopril). Interestingly, during the initial workup, the patient also had elevated calcium of 11 mg/dl and low phosphate at 2.5 mg/dl. In addition, parathyroid hormone (PTH) was elevated at 103 and 95 pg/ml on two occasions, with normal 25-OH vitamin D levels. 24-hoururine calcium was 240mg/dl, and creatinine in urine was 76.4 mg/dl. The calcium creatinine clearance ratio was 2.5%. Diagnosis of primary hyperparathyroidism was made. She had no renal stone, chronic kidney disease, or fractures, with a normal DEXA scan. There was no current indication for parathyroidectomy, and the patient continued to be followed up in the clinic. Clinical lesson: Recent evidence shows cross-talk between the adrenal cortex and parathyroid gland. Our patient may represent such a case, with concomitance of two rare endocrinopathies resulting in difficult-to-control hypertension [1,2]. Thus it is essential to investigate multiple etiologies of secondary hypertension. Reference: Brown JM, Vaidya A. Interactions between adrenal-regulatory and calcium-regulatory hormones in human health. Curr Opin Endocrinol Diabetes Obes . 2014;21(3): 193-201. doi: 10.1097/MED. 0000000000000062 Maniero C, Fassina A, Guzzardo V, et al. Primary hyperparathyroidism with concurrent primary aldosteronism. Hypertension. 2011 Sep;58(3): 341-6. doi: 10.1161/HYPERTENSIONAHA.111.173948. Epub 2011 Aug 8. PMID: 21825220. Presentation: No date and time listed