Effects of renal sympathetic denervation on blood pressure, sleep apnoea severity and metabolic indices: a prospective cohort study

- RSD results in significant but modest reductions in blood pressure.
- There is no reduction in sleep apnoea severity as measured by AHI.
- Markers of carbohydrate and lipid metabolism do not improve with RSD.

BackgroundCatheter-based renal sympathetic denervation (RSD) significantly reduces blood pressure in patients with resistant hypertension, who commonly have obstructive sleep apnoea (OSA). These patients are considered particularly responsive to the antihypertensive effects of RSD, but additional benefits of metabolic control on sleep apnoea severity have not been thoroughly investigated.MethodsThe effect of RSD was evaluated prospectively in a cohort of patients with OSA (apnoea-hypopnea index (AHI) ≥15 events per hour and an Epworth Sleepiness Scale (ESS) score ≤9) and treatment resistant hypertension. Changes in blood pressure, polysomnographic parameters and metabolic indices were evaluated at baseline and six months post procedure.ResultsAt baseline, mean office blood pressure was 166.3/92.8 (14.5/11.7) mmHg and mean ambulatory blood pressure was 154.0/87.3 (11.9/8.5) mmHg. At six months post RSD, mean office blood pressure reduced by 6.6/6.5 (1.9/2.0) mmHg (p < 0.05) and mean ambulatory blood pressure reduced by 8.3/6.2 (2.3/2.0) (p < 0.05). The mean AHI at baseline was 21.3 events/h and 20.5 events/h at six months post RSD, with a mean reduction of 0.9 events/h (95% CI −0.7-1.6, p = 0.39). Glucose at two hours/2 h following tolerance testing reduced by 1.14 mmol/L (95% CI 0.22-2.06, p = 0.03) but changes in other metabolic indices were not statistically significant.ConclusionIn patients with resistant hypertension and OSA, RSD resulted in modest improvements in blood pressure control, but no significant changes in sleep apnoea severity. Our study showed small increments in glucose tolerance but no significant changes in other markers of carbohydrate or lipid metabolism.