The recent experimental and clinical studies evidence a potential bidirectional relationship between sympathetic activity and the endogenous circulating NO synthase inhibitor asymmetric dimethylarginine (ADMA). However, the data are controversial.
The purpose of our study was to assess the change in ADMA level after renal sympathetic denervation (RSDN) in patients with resistant hypertension (RAH).
We examined 19 patients (7 males) with verified RAH [mean age – 59 (28–70) years], who underwent the RSDN by standard protocol (Simplicity, Medtronic). ADMA level was measured by immune-enzyme assay (ADMA direct ELISA Kit, Immunodiagnostic AG, Bensheim, Germany, reference values 0.26–0.64 mcmol/l) at baseline before the RSDN (the first patient was enrolled in 2013), 6 and 12 months after the operation (the last patient was examined in 2015). Statistical analysis was carried out using the program SPSS 17.0, the data are presented as median (25%;75%).
At baseline ADMA was 0.81 (0.3; 1.98) mcmol/l. The increased values were found in 1 male and 9 females (chi-square = 1.9; p = 0.2) without any gender differences compared to those with normal ADMA level. ADMA level remained unchanged at 6-month follow-up: 0.83 (0.35; 0.94) mcmol/l (p = 0.91). Although it decreased by 12-month follow-up visit – 0.66 (0.23; 0.99) mcmol/l, the changes were non-significant (p = 0.6, repeated measures, one-way ANOVA).
Half of RAH patients (53%) demonstrate increased ADMA indicating worse prognosis. Renal denervation failed to decrease ADMA level. However, small sample size and a trend toward improvement of endothelial function deserves further investigation in order to understand who may benefit from the RSDN procedure in the very high risk population with resistant hypertension.
1Almazov National Medical Research Centre, Saint-Petersburg, Russia
2The Federal Center of Otorhinolaryngology, Moscow, Russia
3ITMO University, St Petersburg, Russia