Primary hyperaldosteronism presenting as persistent postpartum hypertension: Illustrative case and systematic review

Variable effect of the post-partum menstrual cycle on aldosterone and renin in women with recent preeclampsia

The purpose of the present study is to identify the impact of the postpartum menstrual cycle on aldosterone, renin, and their ratio of women with and without a preeclamptic pregnancy in the past. To this end, we analysed the data from 59 women with a history of preeclampsia and 39 healthy parous controls. Five to seven months post-partum, we measured aldosterone, renin, and the aldosterone-to-renin ratio during both the follicular and the luteal phase of the menstrual cycle. All measurements were taken in the supine position in the morning. Patients had maintained a standardized sodium diet in the week prior to the measurements. Our results show that in both post-partum women with recent preeclampsia and controls, average levels of renin and aldosterone are significantly elevated in the luteal phase as compared to the follicular phase. The aldosterone-to-renin ratio does not differ between the two phases in either group. Compared to controls, women with recent preeclampsia have significantly lower levels of renin, aldosterone, and aldosterone-to-renin ratio in the follicular phase. This remained consistent in the luteal phase, except for renin. A close correlation existed between the luteal and follicular aldosterone-to-renin ratio in the control group but not in the preeclampsia group. We conclude that both renin and aldosterone are significantly affected by the menstrual cycle whereas the resulting aldosterone-to-renin ratio is not. Post-partum women with recent preeclampsia tend to have lower values for aldosterone and the aldosterone-to-renin ratio than controls.

Primary aldosteronism in pregnancy

Primary aldosteronism (PA) is the most common form of secondary hypertension. Although hypertensive disorders seem to affect around 5-10% of pregnancies worldwide, literature counts less than 80 cases of PA diagnosed during the peri-partum period. In this review we discuss about current knowledge on pathophysiology, natural history, diagnosis and treatment of PA in pregnancy. Because of the physiologic changes in the renin-angiotensin-aldosterone system (RAAS) and the contraindication to both confirmatory test and subtype differentiation, diagnosis of PA during pregnancy is challenging and relies mostly on detection of low/suppressed renin and high aldosterone levels. The course of pregnancy in patients with PA is highly variable, ranging from progesterone-induced amelioration of blood pressure (BP) control to severe and resistant hypertension with potential maternal and fetal complications. Mineralcorticoid receptor antagonists (MRA) are the recommended and most effective drugs for treatment of PA. As the anti-androgenic effect of spironolactone can potentially interfere with sexual development, their prescription is not recommended during pregnancy. On the other side, eplerenone, has proven to be safe and effective in 6 pregnant women and may be added to conventional first line drug regimen in presence of resistant hypertension or persistent hypokalemia. Ideally, patients with unilateral forms of PA should undergo adrenalectomy prior to conception, however, when PA is diagnosed during pregnancy and medical therapy fails to adequately control hypertension or its complications, adrenalectomy can be considered during the second trimester in case of unilateral adrenal mass at MRI-scan.

Primary Aldosteronism Presenting with Hypertension Five Days after Delivery: A Case Report and Literature Review

A 35-year-old Japanese woman with no history of hypertension developed hypertension 5 days after normal delivery. Endocrinological and radiological examinations indicated primary aldosteronism (PA) and a 1.4-cm left adrenal tumor. The patient underwent laparoscopic adrenalectomy, and a diagnosis of aldosterone-producing adenoma was confirmed immunohistochemically. Her plasma aldosterone concentration and blood pressure normalized. Cases of PA presenting with hypertension in the postpartum period have been reported. This case suggests that PA should be considered in women with postpartum hypertension, especially in those with blood pressure that suddenly increases shortly after delivery, even if they were normotensive before and throughout pregnancy.

A Case Report of Recurrent Hypokalemia During Pregnancies Associated With Nonaldosterone-Mediated Renal Potassium Loss

Rationale

Geller et al reported a rare mutation in the mineralocorticoid receptor (MR) resulting in constitutive MR activity. Progesterone, normally an MR antagonist, acts as a potent agonist with this mutation. Progesterone levels can increase 100-fold during pregnancy and thus lead to increased MR activity in this setting, resulting in hypertension (HTN) and hypokalemia during pregnancy and resolution of hypokalemia after delivery.

Presenting concerns

Our patient was a 33-year-old African American female with a history of pregnancy-induced HTN associated with hypokalemia during her last pregnancy. She presented with muscle weakness from profound hypokalemia complicated by nephrogenic diabetes insipidus (DI) and rhabdomyolysis.

Diagnosis

Her admission potassium was 1.9 mmol/L (3.5-5.1 mmol/L) with a 24-hour urine potassium of 35 mmol per day and an unmeasurable serum aldosterone level. Her potassium normalized 1 day after delivery off potassium supplementation and amiloride, which were last given 1 day prior to her delivery. Recurrent hypokalemia from nonaldosterone-mediated renal potassium wasting during pregnancy (with normal potassium in a nongestational state) is consistent with the cases of gain-of-function mutation in MR that Geller et al report. A definite diagnosis requires genetic analysis.

Interventions

Her hypokalemia was refractory to potassium replacement but quickly responded to an inhibitor of the epithelial sodium channel (ENaC), amiloride.

Outcomes

Her potassium normalized on amiloride 10 mg per day and KCL 40 mEq daily during the remainder of her pregnancy, and her nephrogenic DI resolved after this correction of hypokalemia. After her delivery, her potassium remained normal off the potassium supplements and amiloride.

Novel findings

Pregnancy-induced hypokalemia from an activating MR mutation has rarely been reported. Pregnancy-induced HTN is often the first differential diagnosis in a patient who develops worsening in her HTN during pregnancy. We should also consider the possibility of a gain-of-function mutation in MR in these patients who also have associated hypokalemia.

Nearly fatal hypokalaemia due to non-hypertensive primary hyperaldosteronism in the post partum

A previously healthy postpartum 33-year-old woman was admitted at the emergency department after two episodes of syncope. In the waiting room, she collapsed, ventricular fibrillation was detected, and she was reanimated by electric cardioversion. At admission, she was conscient, with blood pressure of 102/74 mm Hg and heart rate of 78 bpm. In the laboratory workup, severe hypokalaemia was found (K⁺ 1.77 mEq/L). Abdominopelvic CT revealed a 27 mm nodule in the right adrenal gland. High aldosterone and low plasma renin levels were detected, and the diagnosis of primary hyperaldosteronism was made, although she never had hypertension. Posteriorly, a cosecretion of aldosterone and cortisol was found. Two months after admission, the patient remained stable with normal K⁺ levels under spironolactone and a right adrenalectomy was performed. The cure of primary hyperaldosteronism and a partial adrenal insufficiency were confirmed. K⁺ levels and blood pressure remained normal without treatment and 10 months after surgery hydrocortisone was suspended.

Curative resection of an aldosteronoma causing primary aldosteronism in the second trimester of pregnancy

SUMMARY

A 29-year-old primigravida woman with a known history of primary aldosteronism due to a right aldosteronoma presented with uncontrolled hypertension at 5 weeks of estimated gestation of a spontaneous pregnancy. Her hypertension was inadequately controlled with pharmacotherapy which lead to the consideration of surgical management for her primary aldosteronism. She underwent curative right unilateral adrenalectomy at 19 weeks of estimated gestational age. The procedure was uncomplicated, and her blood pressure normalized post-operatively. She did, however, have a preterm delivery by cesarean section due to intrauterine growth retardation with good neonatal outcome. She is normotensive to date.

LEARNING POINTS

Primary aldosteronism is the most common etiology of secondary hypertension with an estimated prevalence of 5-10% in the hypertensive population. It is important to recognize the subtypes of primary aldosteronism given that certain forms can be treated surgically. Hypertension in pregnancy is associated with significantly higher maternal and fetal complications. Data regarding the treatment of primary aldosteronism in pregnancy are limited. Adrenalectomy can be considered during the second trimester of pregnancy if medical therapy fails to adequately control hypertension from primary aldosteronism.