Effect of calf bioimpedance ratio for volume evaluation on hypertension in hemodialysis patients / 中华肾脏病杂志

ABSTRACT

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.