Supine and upright plasma renin (PR) and aldosterone (ALD) in patients with adrenal incidentaloma (AI)
Miomira Ivovic, Milos Stojanovic, Milina Tancic-Gajic, Ljiljana Marina, Marija Barac & Svetlana Vujovic
AI are incidentally discovered adrenal masses without any prior suspicions of adrenal disease. They are most frequently hormonally inactive, with arterial hypertension (AH) as a common finding.
The aim was to determine upright and supine PR and ALD levels in patients with AI, normotensive and hypertensive.
Two hundred and eight patients (148 women and 60 men, mean age 55.08±11.02 years, mean BMI 27.91±4.6 kg/m2) with AI (confirmed by CT/MRI) were admitted to our Institute. After endocrine testing 91 normokaliemic patients had nonfunctional adrenal mass, in which we determined PR and ALD. We divided them in two groups: I: 49 patients (38 women and 11 men, mean age 56.62±10.33 years, mean BMI 28.6±4.32 kg/m2) with confirmed AH; II: 42 patients (27 women and 15 men, mean age 53.34±11.58 years, mean BMI 26.99±4.81 kg/m2), normotensive. Blood samples were taken in supine and after 2 h upright position. PR and ALD levels were determined by RIA kits. Statistical analysis was done by Wilcoxon signet rank, MannWhitney and Fisher Exact Test.
In the whole group mean supine PR values were 1.13±1.59 ng/ml per h, and mean postural PR values were 2.92±3.87 ng/ml per h; mean supine ALD values were 69.16±92.16 ng/l, and mean postural ALD values were 217±184.18 ng/l. ALD/PR over 30 was detected in 18.61% patients. Supine PR values were significantly lower in hypertensive group (1.6 vs 0.71 ng/ml per h; P<0.01) as well as were postural values (4.11 vs 1.89 ng/ml per h; P<0.01). There was no significant difference in supine and upright mean ALD values between the groups (supine 77.21 vs 62.27 pg/ml; P=0.679; upright 216.8 vs 219.9 pg/ml, P=0.400). A difference in percentage of patients with ALD/PR ratio >30 between tested groups was significant (19.61 vs 31.25%, P<0.01).
In our study, hypertensive patients with adrenal tumors had lower PR activity than normotensive patients in light of normal ALD supine and upright values without significant difference between the groups.