Abstract
BACKGROUND AND OBJECTIVES: The plasma concentration of the endogenous inhibitor of nitric oxide synthase asymmetric dimethylarginine (ADMA) associates with sympathetic activity in patients with CKD, but the driver of this association is unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this longitudinal study (follow-up: 2 weeks-6 months), repeated measurements over time of muscle sympathetic nerve activity corrected (MSNAC), plasma levels of ADMA and symmetric dimethylarginine (SDMA), and BP and heart rate were performed in 14 patients with drug-resistant hypertension who underwent bilateral renal denervation (enrolled in 2013 and followed-up until February 2014). Stability of ADMA, SDMA, BP, and MSNAC over time (6 months) was assessed in two historical control groups of patients maintained on stable antihypertensive treatment. RESULTS: Time-integrated changes in MSNAC after renal denervation ranged from -40.6% to 10% (average, -15.1%), and these changes were strongly associated with the corresponding changes in plasma ADMA (r= 0.62, P=0.02) and SDMA (r=0.72, P=0.004). Changes in MSNAC went along with simultaneous changes in standardized systolic (r=0.65, P=0.01) and diastolic BP (r=0.61, P=0.02). In the historical control groups, no change in ADMA, SDMA, BP, and MSNAC levels was recorded during a 6-month follow-up. CONCLUSIONS: In patients with resistant hypertension, changes in sympathetic activity after renal denervation associate with simultaneous changes in plasma levels of the two major endogenous methylarginines, ADMA and SDMA. These observations are compatible with the hypothesis that the sympathetic nervous system exerts an important role in modulating circulating levels of ADMA and SDMA in this condition.