Physiologic variance of corticotropin affects diagnosis in adrenal vein sampling.
OBJECTIVE
Differentiating unilateral form from bilateral is a critical diagnostic step in primary aldosteronism (PA), for which adrenal vein sampling (AVS) is accepted to be the most reliable. However, variance of corticotropin could affect the diagnosis in AVS.


METHODS
We conducted simultaneous bilateral AVS on ten biochemically diagnosed PA cases, and used the aldosterone-to-cortisol ratio (A/C) of the samples for the diagnosis. The diagnosis by AVS after a low-dose (0.1 microg) ACTH stimulation, which can provoke maximum-physiologic corticotropic response, was compared with those before the stimulation and after the standard-dose (250 microg) ACTH stimulation.


RESULTS
In half of the cases, the low-dose pre-stimulation affected the diagnosis. In four out of ten cases, the side-to-side ratios of A/C were changed in the basal/low-dose/standard-dose AVS as 6.62/2.46/0.63, 2.13/0.41/0.14, 1.88/2.38/2.40, and 1.96/2.27/1.90 respectively. In three out of ten cases, the adrenal vein to the matching inferior vena cava ratio of A/C was also changed across 1, the cut-off to indicate suppression of aldosterone secretion. Additionally, the confirmation of successful sampling was difficult in five out of ten and two out of ten cases of the basal and low-dose AVS respectively, whereas it was easy in all the cases of the standard-dose AVS.


CONCLUSIONS
The diagnosis in the basal AVS could be affected by the physiologic fluctuation of ACTH at relatively high prevalence. The basal AVS would be unreliable to differentiate two forms of PA.
Tanemoto
Masayuki
M
Division of Nephrology, Hypertension & Endocrinology, Department of Medicine, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan. mtanemoto-tky@umin.ac.jp
Suzuki
Takehiro
T
Abe
Michiaki
M
Abe
Takaaki
T
Ito
Sadayoshi
S
D000311:Adrenal Glands / Q000098:blood supply*; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood / Q000378:metabolism; D003366:Cosyntropin / Q000097:blood; D003940:Diagnostic Techniques, Endocrine / Q000592:standards*; D005260:Female; D006728:Hormones / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006929:Hyperaldosteronism / Q000097:blood* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014680:Veins; D014682:Vena Cava, Inferior
D006728:Hormones; D003366:Cosyntropin; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone