Conclusion
In summary, this post-hoc evaluation suggests that short-term auricular tVNS and sham treatment do not differ with respect to changes in serum aldosterone concentration in healthy subjects. Moreover, we observed an interaction effect of sex and age on circulating aldosterone levels in the entire study cohort, where younger women had the highest and older women the lowest concentrations. However, due to several limitations of this study, no direct conclusions can be drawn, and further studies on the effects of tVNS and sex differences in the regulation of RAAS components are required.