SAT-177 Relationship Between Visceral Fat and the Position of Adrenal Glands in Cranial-Caudal Direction in Patients with Primary Aldosteronism

Abstract

Context: Adrenal glands locate at the retroperitoneal space and could be affected their positions by some factors. Adrenal glands being surrounded by visceral adipose tissue (VAT), we have hypothesized that the VAT amount influences the position of adrenal glands in cranial-caudal direction. In patients with primary aldosteronism (PA), comprehending the position of adrenal glands in cranial-caudal direction might be useful to predict the position of adrenal veins before performing adrenal venous sampling. Objectives: To clarify the influence of VAT amount on the position of adrenal glands, we investigated the correlation of visceral fat parameters with the position difference of adrenal glands in cranial-caudal direction in patients with PA. Materials and methods: This retrospective observational study included patients with PA according to the guidelines of both the Japan Endocrine Society and the Japan Society of Hypertension. Those with adrenal tumors more than 10 mm in diameter in computed tomography (CT) were excluded. We measured the position difference of the adrenal glands in cranial-caudal direction, from the top of right adrenal gland to the top of left adrenal gland by CT. We correlated visceral fat percentage (VF%), visceral fat area (VFA), and subcutaneous fat area (SCFA) evaluated by CT studies with the position difference of adrenal glands in cranial-caudal direction. Results: We analyzed 150 patients [male (n = 50), female (n = 100)]. Patients’ characteristics: Age was 54.8 ± 11.4, body mass index 24.9 ± 3.8 kg/m2, plasma aldosterone concentration 133.5 [101–176] pg/ml, plasma renin activity 0.3 [0.2–0.5] ng/ml/h, VF% 25.8 [19.8–33.6] %, VFA 88.3 [60.9–125.0] cm2, and SCFA was 147.4 [105.6–193.4] cm2 (mean ± SD, or median [interquartile range]). The position difference of adrenal glands in cranial-caudal direction was 9.7 ± 10.0 mm. In 120 patients (80.0%), left adrenal glands locate at the upper position comparing to right adrenal glands. In 19 patients (12.7%), right adrenal glands were positioned at the upper comparing to left adrenal glands. A positive correlation of VF%, VFA with the position difference of adrenal glands in cranial-caudal direction were shown (r = 0.451, p < 0.001, r = 0.426, p < 0.001, respectively). No significant correlation of SCFA with the position difference of adrenal glands in cranial-caudal direction was shown (r = 0.122, p = 0.139). In patients with more VAT amount, right adrenal glands locate at the upper position comparing to left adrenal glands. In patients with less VAT amount, left adrenal glands locate at the upper position comparing to right adrenal glands. Conclusions: Regardless of the variation of the position of adrenal gland on each side, the correlation was found between VAT and the position difference of adrenal glands in cranial-caudal direction in PA.