Effects of mildly increasing dialysis sodium removal on renin and sympathetic system in hemodialysis patients

摘要

Background It has been argued that the benefits of reducing sodium loading may be offset by increased activation of the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system.This study aimed to investigate the long-term effects of an increase in dialysis sodium removal on circulating RAAS and sympathetic system in hypertensive hemodialysis (HD) patients with "normal" post-HD volume status.Methods Thirty hypertensive HD patients were enrolled in this pilot trial.After one month period of dialysis with standard dialysate sodium of 138 mmol/L,the patients were followed up for a four months period with dialysate sodium set at 136 mmol/L,without changes in instructions regarding dietary sodium control.During the period of study,the dry weight was adjusted monthly under the guidance of bioimpedance spectroscopy to maintain post-HD volume status in a steady state; 44-hour ambulatory blood pressure,plasma renin,angiotensin Ⅱ (Ang Ⅱ),aldosterone,and norepinephrine (NE) were measured.Results After four months of HD with low dialysate sodium of 136 mmol/L,44-hour systolic and diastolic blood pressures (BPs) were significantly lower (-10 and-6 mmHg),in the absence of changes in antihypertensive medications.No significant changes were observed in plasma renin,Ang Ⅱ,aldosterone,and NE concentrations.The post-HD volume parameters were kept constant.Conclusion Mildly increasing dialysis sodium removal over 4 months can significantly improve BP control and does not activate circulating RAAS and sympathetic nervous system in hypertensive HD patients.