No reference criteria can definitively distinguish patients with primary aldosteronism plus subclinical Cushing syndrome from those with primary aldosteronism or subclinical Cushing syndrome alone, according to study results published in BMC Endocrine Disorders. However, patients with primary aldosteronism who have a relatively large adrenal tumor should be assessed for concurrent subclinical Cushing syndrome.
There is limited research examining the clinicopathological features of hyperaldosteronism with concurrent subclinical hypercortisolism. To compare clinical features between patients with primary aldosteronism, subclinical Cushing syndrome, and both conditions, researchers conducted a retrospective study at a single healthcare center in Saitama, Japan. The researchers assessed the proportion of patients with diabetes, differences in serum potassium concentration, and maximum adrenal tumor diameter between the 3 groups.
Of 71 patients included in the analyses, 45 had primary aldosteronism, 12 had subclinical Cushing syndrome, and 14 had both conditions.
A significantly greater percentage of patients with primary aldosteronism and subclinical Cushing syndrome had diabetes compared with those who had only primary aldosteronism (50.0% vs 14.0%; P <.05), but there was no significant difference compared with the group that had only subclinical Cushing syndrome.
Patients with both primary aldosteronism and subclinical Cushing syndrome had significantly lower serum potassium concentrations compared with the subclinical Cushing syndrome group (3.2±0.8 vs 4.0±0.5 mEq/L; P <.01). No significant difference was noted in this regard between patients with primary aldosteronism and subclinical Cushing syndrome and those who had primary aldosteronism only.
Among patients who had a unilateral adrenal tumor (n=65), those in the group with both primary aldosteronism and subclinical Cushing syndrome had a significant greater maximum tumor diameter on computed tomography scans compared with that in patients in the primary aldosteronism group (2.7±0.1 vs 1.34±0.1 cm; P <.001). Tumor size was also greater in the group with subclinical Cushing syndrome compared with the group with primary aldosteronism (2.7±0.2 vs 1.34±0.1 cm; P <.001) but not compared with the group with both conditions.
The study had several limitations, including its retrospective design and relatively small cohort. The researchers also noted that not all patients underwent adrenal venous sampling or had a histopathological diagnosis.
“We could not obtain any reference criteria to surely distinguish patients with concurrent endocrinopathies from those with a single endocrinopathy,” the researchers wrote. However, they did conclude that for patients with an adrenal tumor ≥1 cm in diameter, subclinical Cushing syndrome should be suspected.
Yasuda S, Hikima Y, Kabeya Y, et al. Clinical characterization of patients with primary aldosteronism plus subclinical Cushing’s syndrome. BMC Endocr Disord. 2020;20:9.