Syncope is a transient loss of consciousness resulting from cerebral hypoperfusion. Vasovagal syncope (VVS) is a form of orthostatic intolerance (OI). Its clinical signs such as dizziness and hypotension may mimic symptoms of adrenal insufficiency. The objective of this study was to evaluate the adrenal gland function in patients with vasovagal syncope after stimulation with synthetic adrenocorticotropic hormone (ACTH). Case-control study on patients with VVS and healthy controls. The study involved 42 participants, including 27 patients diagnosed with VVS using the head-up tilt test and 15 healthy individuals with no history of syncope or any orthostatic symptoms. Serum cortisol and aldosterone concentrations were measured under basal conditions and at 30 and 60 min after intramuscular ACTH stimulation. Patients with VVS had significantly higher cortisol levels at baseline (441 ± 143 vs. 331 ± 84.7 nmol/L, = 0.01), at 30 min (802 ± 143 vs. 686 ± 105 nmol/L, p = 0.01) and at 60 min (931 ± 141 nmol/L vs. 793 ± 147 nmol/L, = 0.001) after ACTH administration (Synacthen 250 μg). Plasma aldosterone increased after ACTH stimulation, but did not show significant differences among groups. Furthermore, there was also no significant correlation between cortisol levels and blood pressure or heart rate. Patients diagnosed with VVS have higher cortisol levels both at baseline and after ACTH stimulation. This finding indicates that individuals with VVS have higher adrenocortical activity potentially as a response to the orthostatic stress induced by syncope, which acts as a stressful stimulus on the autonomic nervous system.

中文翻译：

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血管迷走性晕厥患者肾上腺皮质活性增加


晕厥是由于脑灌注不足导致的短暂意识丧失。血管迷走性晕厥 (VVS) 是直立不耐受 (OI) 的一种形式。其临床症状如头晕和低血压可能类似于肾上腺功能不全的症状。本研究的目的是评估合成促肾上腺皮质激素（ACTH）刺激后血管迷走性晕厥患者的肾上腺功能。针对 VVS 患者和健康对照的病例对照研究。该研究涉及 42 名参与者，其中包括 27 名通过平视倾斜测试诊断为 VVS 的患者和 15 名没有晕厥病史或任何直立症状的健康个体。在基础条件下以及肌内 ACTH 刺激后 30 和 60 分钟测量血清皮质醇和醛固酮浓度。 VVS 患者的皮质醇水平在基线时显着升高（441 ± 143 vs. 331 ± 84.7 nmol/L，= 0.01）、30 分钟时（802 ± 143 vs. 686 ± 105 nmol/L，p = 0.01）和 60 分钟时给予 ACTH（Synacthen 250 μg）后分钟（931 ± 141 nmol/L vs. 793 ± 147 nmol/L，= 0.001）。 ACTH刺激后血浆醛固酮增加，但各组之间没有表现出显着差异。此外，皮质醇水平与血压或心率之间也没有显着相关性。诊断为 VVS 的患者在基线时和 ACTH 刺激后皮质醇水平较高。这一发现表明，VVS 患者的肾上腺皮质活性较高，可能是对晕厥引起的体位应激的反应，晕厥对自主神经系统产生压力刺激。