“…Furthermore, 8 out of 10 studies were conducted in out-patient clinics [36,37,42,43,50,51,52,53], with community-dwelling individuals being recruited in two other studies [40,41]. Only one study focused on healthy individuals [40], while other studies recruited patients with social anxiety [50], moderate depression and anxiety [52], generalized anxiety disorder (GAD) [51], stress-related complaints [41], breast cancer [36,42], rheumatoid arthritis [37], heart palpitations [43], and post-menopausal BMI > 30 [53]. At least one HRV outcome was assessed in four studies, including LF [41,43,50], HF [41,43,50], LF/HF ratio [36,41,43,50], SDNN and RMSSD [36,41,43], and at least one inflammatory marker was assessed in 6 studies, including CRP [37,40,42,52,53] and IL-6 [40,42,51,53].…”