Ott C, et al. – This study assessed salt intake and tissue sodium (Na⁺) content in patients with treatment–resistant hypertension (TRH) in order to gauge the influence of renal denervation (RDN) on Na⁺ homeostasis. RDN substantially attenuated blood pressure (BP), without causing tissue Na⁺ content of the muscle and skin to mobilize and reduce. These data suggest that the BP reduction after RDN is unrelated to Na⁺ homeostasis.

Methods

• RDN was performed in 41 patients with TRH (office BP ≥140/90 mmHg and diagnosis confirmed by 24-h ambulatory BP monitoring).
• Using 3.0 T magnetic resonance imaging, tissue Na⁺ content was assessed non-invasively before and 6 months after RDN.
• In addition, 24-h urinary Na⁺ excretion as an estimate of salt intake and spot urine Na⁺/K⁺ excretion were assessed.

Results

• Findings demonstrated a significant fall in BP (office: -17 ± 20/-10 ± 12 mmHg; 24-h: -11 ± 13/-6 ± 9 mmHg, allp < 0.001) 6 months after RDN.
• In contrast, no change was observed in tissue Na⁺ content of the muscle (20.1 ± 3.9 vs. 20.7 ± 4.0 mmol/L, p = 0.229) and skin (24.4 ± 6.5 vs. 24.8 ± 6.6 mmol/L, p = 0.695) after RDN.
• Moreover, RDN did not change salt intake, but acutely increased Na⁺/K⁺ ratio.