Sex differences in sympathetic activity and vascular stiffness in adults with chronic kidney disease (CKD).

BACKGROUND: Chronic kidney disease (CKD) is characterized by sympathetic nervous system (SNS) overactivity that contributes to increased vascular stiffness and cardiovascular risk. While it is well established that SNS activity and vascular stiffness are substantially elevated in CKD, whether sex differences in autonomic and vascular function exist in CKD remains unknown. We tested the hypothesis that compared to females, males with CKD have higher baseline sympathetic activity that is related to increased arterial stiffness.

METHODS: 129 participants (96 males and 33 females) with CKD Stages III and IV were recruited and enrolled. During two separate study visits, vascular stiffness was assessed by measuring carotid-to-femoral pulse wave velocity (cfPWV) and resting muscle sympathetic nerve activity (MSNA) was measured by microneurography.

RESULTS: Males with CKD had higher resting MSNA compared to females with CKD (68 ± 16 vs 55 ± 14 bursts/100 heart beats, p= 0.005) while there was no difference in cfPWV between the groups (p= 0.248). Resting MSNA was not associated with cfPWV in both males and females.

CONCLUSIONS: Males with CKD have higher resting sympathetic activity compared to females with CKD. However, there was no difference in vascular stiffness between sexes. There was no correlation between resting MSNA and cfPWV, suggesting that non-neural mechanisms may play a greater role in the progression of vascular stiffness in CKD, particularly in females.