Background:
Over-activation of renal sympathetic nervous system and low-grade systemic inflammation are thought to be common features of hypertension. Renal Denervation (RDN) reduces sympathetic activity in patients with resistant hypertension. However, its effect on systemic inflammation has not been investigated.
Aim:
To determine the effect of RDN-induced sympathetic inhibition on monocyte activation and systemic inflammation in hypertensive patients.
Methods:
Peripheral blood was obtained from 42 patients who underwent RDN for uncontrolled blood pressure (BP) at baseline, at 3 months and 6 months post-procedure. Ambulatory BP, overall activation status of monocyte as well as monocyte subsets and inflammatory markers were assessed at each time point.
Results:
RDN significantly lowered 24-hour ambulatory BP at 3 months (150.5/81.0 mmHg to 144.7/77.9 mmHg), which was sustained at 6 months (144.7/78.6 mmHg). The overall monocyte activation was significantly decreased (3 months, 4079.4 MFI to 3182.0 MFI; 6 months, 3457.62 MFI) post-RDN, specifically in the subset of classical monocytes (6 months, 4696.8 MFI to 3958.8 MFI). In line with this, reduction of several inflammatory markers were observed, including monocyte-platelet aggregates at 3 months (34% [680 of 2000 monocyte events] to 11.85% [237 of 2000 monocyte events]) and plasma levels of MCP-1 (3 months, 144.9 pg/ml to 100.1 pg/ml; 6 months, 122.2 pg/ml), IL-1β (3 months, 18.3 pg/ml to 10.8 pg/ml; 6 months, 12.2 pg/ml), TNF-α (3 months, 167.5 pg/ml to 78.4 pg/ml; 6 months, 111.1 pg/ml), IL-12 (3 months, 59.8 pg/ml to 9.9 pg/ml; 6 months, 21.4 pg/ml) and IL-6 (3 months, 2.4 pg/ml to 1.5pg/ml; 6 months, 1.9 pg/ml). A positive correlation was observed between baseline muscle sympathetic nerve activity and monocyte activation (R=0.62) and changes observed at both time points (3 months, R=0.63; 6 months, R=0.88) post-procedure.
Conclusions:
Inhibition of sympathetic activity via RDN is associated with a reduction of monocyte activation and other circulating inflammatory markers in hypertensive patients. These findings point to a direct interaction between the inflammatory and sympathetic nervous system, which is of central relevance for the understanding of beneficial cardiovascular effects of RDN.
Suppression of Cardiac Sympathetic Nervous System during Dental Surgery in Hypertensive Patients.
