Sympathetic vasomotor tone is associated with depressive symptoms in young females: a potential link between depression and cardiovascular disease

Background: Although increased sympathetic nervous system (SNS) activity is commonly associated with major depressive disorder (MDD) and cardiovascular disease (CVD), a biomarker linking these two entities remains elusive. We therefore evaluated the relationship between depressive symptoms and cardiovascular modulation by heart rate variability (HRV), brachial blood pressure (BP), ambulatory BP (ABP), and low frequency component of systolic BP variability (LFSBP), a surrogate of sympathetic vasomotor tone. We hypothesized that LFSBP would be the strongest predictor of depressive symptoms compared with HRV and BP measurements.

Methods: Eighty young healthy female subjects (20.51 ± 2.82 years) were evaluated for depressive symptoms using the Center for Epidemiologic Studies Depression Scale (CES-D). Data collection was conducted after a 10-minute resting period. Beat-to-beat BPs were recorded for 5-minute at baseline (BASE) followed by a 3-minute cold pressor test (CPT). ABP was obtained for 24 hours.

Results: Hierarchical multiple regression analyses indicated that LFSBP at BASE was a stronger predictor of CES-D variance than BP and HRV indices, with LFSBP uniquely accounting for 8.1% of variance in CES-D scores during laboratory beat-by-beat BP assessments and 44.7% in ABP assessments. Individuals with acute depression scores (n = 12; CES-D ≥ 16) had significantly higher (P < 0.001) mean LFSBP values (6.66 ± 2.54 mm Hg(2)) than the remaining sample (3.32 ± 2.2 mm Hg(2)), whereas no other significant differences were detected in any of the other cardiovascular variables. Cardiovascular responses to CPT did not predict CES-D scores.

Conclusions: These findings suggest that LFSBP could be a biomarker of neurovascular functioning with potential clinical implications for understanding the interaction between MDD and CVD.