ABSTRACT
<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Blood Pressure , Hypertension , Therapeutics , Prospective Studies , Renal Dialysis , Renin-Angiotensin System , Sodium , Pharmacology , Sympathetic Nervous SystemABSTRACT
Objective To elucidate the effect of bioimpedance ratio in the calf (calf-RBI) for volume evaluation on hypertension in hemodialysis (HD) patients. Methods Bioimpedance in the right calf was measured by bioimpedance spectroscopy (BIS). As an index of volume status, calf-RBI was calculated as follows: calf-RBI =impedance at 200 kHz / impedance at 5 kHz. The range of age-stratified 1SD from mean calf-RBI in the healthy control was assumed as the target range for the corresponding HD patients. The dry body weight (DBW) was stepwise decreased under the guidance of calf-RBI. The changes of calf-RBI, blood pressure and antihypertensive medications were recorded and correlation analysis among indexes was performed. Results The calf-RBI showed a normal distribution in both healthy subjects and HD patients. The calf-RBI was positively correlated with age, but not with gender or BMI. Forty-two patients with (35.9%) calf-RBI beyond target range were identified in 117 HD patients. The percentage of uncontrolled hypertensive individuals was significantly higher as compared to those with calf-RBI within or below target range (59.5% vs 33.3% and 16.7%, P＜0.01). The percentage of uncontrolled hypertensive individuals and the dose of antihypertensive medications was significant improved after decreasing the DBW in the patients with calf-RBI beyond target range (74.1% vs 33.3%, P＜0.01) and defined daily dose (2.00±2.28 vs 2.49±2.47, P＜0.05 ). Conclusions The age-stratified calf-RBI may be used as a useful index for estimation of volume status, and has a good association with clinical manifestations. Recognition and correction of chronic fluid overload based on age-stratified calf-RBI is helpful in hypertension control for hemodialysis patients.
ABSTRACT
Objective To investigate the association between arterial stiffness of the common carotid artery(CCA)and insulin resistance in hemodialysis patients. Methods Arterial stiffness index β of CCA was evaluated by an ultrasonic phase-lock Echo-tracking system in 80stable non-diabetic hemodialysis patients.Insulin resistance was detected by the homeostasis model assessment method(HOMA-IR).Plasma hemoglobin,serum albumin,total cholesterol,high density lipoprotein,low density lipoprotein,triglyceride,lipoprotein(a),ApoA1,ApoB,CRP,calcium,phosphorus and creatinine were determined by standard methods. Results The stiffness index β was 11.41±4.13 in patients with previous cardiovascular disease(CVD)and 9.75±3.63 in those without CVD(P＜0.05).The stiffness index β was positively correlated with HOMA-IR(r=0.321,P＜0.01),as well as with age(r=0.376,P＜0.01),pulse pressure(r=0.267,P＜0.05),and duration of hemodialysis(r=0.219,P＜0.05).In stepwise multiple regression analysis,HOMA-IR(β=0.228,P＜0.05)and age(β=0.308,P＜0.01)were identified as significant independent variables for stiffness index β of CCA. Conclusions Insulin resistance is associated with aaefial stiffness in nondiabetic hemodialysis patients.The increased arterial stiffness may be the link between insulin resistance and cardiovascular morbidity as well as mortality in hemodialysis patients.