Prevalence of primary aldosteronism in hypertensive kidney transplant recipients: A cross-sectional study

A case of primary aldosteronism with excessive secretion of renin that was unmasked by kidney transplantation

A 42-year-old man showed marked hypokalemia after kidney transplantation. He was diagnosed with hypertension and suffered from acute myocardial infarction at 33 and 38 years of age. At 40 years of age, hemodialysis was introduced. A left adrenal tumor was noted and suspected as a non-functional adrenal adenoma at that time. Therefore, he received a living-donor kidney transplant at 42 years of age. After kidney transplantation, the serum creatinine level dropped. His blood pressure remained high, and the serum potassium level decreased. The PRA and PAC were elevated, and ARR was not elevated. Based on the results of various confirmatory tests and vein sampling, he was diagnosed with excessive secretion of renin from the native kidneys that was complicated by primary aldosteronism (PA), and left nephrectomy and adrenalectomy were performed. The overproduction of aldosterone in the resected adrenal adenoma and over secretion of renin in the kidney with arteriolosclerosis were immunohistologically confirmed. After surgery, the PAC decreased, but the PRA did not decrease. The postoperative serum potassium level improved, and the blood pressure was well controlled with a small dose of medication. This is the first reported case of PA with hyperreninemia after kidney transplantation. It should be noted that PA in dialysis patients and kidney transplant recipients may not fulfill the usual diagnostic criteria of an elevated ARR. In such patients, PA should be suspected based on the absolute value of the PAC and responsiveness to ACTH stimulation, and adrenal and renal vein sampling is required for a definitive diagnosis.

A Real Saline Challenge: Diagnosing Primary Aldosteronism in the Setting of Chronic Kidney Disease

Primary aldosteronism (PA) is the most common cause of secondary hypertension but remains largely undiagnosed. Chronic kidney disease (CKD) complicates the diagnosis of PA by affecting the biochemical screening evaluation and confirmatory testing, and by increasing the complication rate of adrenal venous sampling (AVS). To raise clinician awareness of the challenges of PA diagnosis in CKD, we present an illustrative case with subsequent review of the literature and discuss some recent developments in PA diagnostic strategies particularly applicable to the CKD population. A 67-year-old man with stage IIIb CKD was suspected of having PA due to treatment with 6 antihypertensive agents and the presence of intermittent hypokalemia. He had a positive biochemical screen for PA, and AVS demonstrated unilateral aldosterone excess. Subsequently, unilateral adrenalectomy resolved his PA, eliminating the patient’s hypokalemia and improving his blood pressure. A MEDLINE literature search revealed 10 studies totaling 11 cases (including our own) of PA diagnosed in the setting of CKD. For each case, the clinical presentation, biochemical data, results of cross-sectional imaging, AVS details, and clinical response to surgery or medical therapy were characterized. The optimal strategy for the diagnosis and management of PA patients with CKD is not known. Although CKD patients often receive screening and subtype testing for PA similar to non-CKD patients, there are challenges in the interpretation of these tests. Novel strategies may include less invasive subtype testing or empiric treatment with mineralocorticoid receptor antagonists but additional studies are necessary.

Chronic kidney disease in adrenal disorders

PURPOSE OF REVIEW

This review will focus on hypertension due to underlying adrenal disorders in chronic kidney disease (CKD). Diagnosis of adrenal hypertension and particularly primary aldosteronism (PA) in CKD is frequently not pursued. We outline limitations that advanced kidney disease poses on the diagnostic work up of these disorders and provide a framework for approaching CKD patients suspected of having an adrenal disorder. Recognition of these disorders is important as they are often underdiagnosed which leads to poorer outcomes.

RECENT FINDINGS

Adrenal disease associated with hypertension in CKD is most commonly due to PA whereas pheochromocytoma and Cushing's disease are important but less common. Diagnosis of these diseases is important as their identification leads to better blood pressure control and can possibly mitigate the risk of progression of CKD. Work up and treatment of PA has been shown to be safe and is associated with less antihypertensive medication requirement for the associated hypertension and slower progression of CKD.

SUMMARY

This chapter summarizes the importance of recognizing adrenal hypertension in CKD and reinforces the need for physicians to pursue these diagnoses in CKD patients as this is safe and improves both BP control and delays progression of CKD.