Effect of Dialysate Temperature and Diabetes on Autonomic Cardiovascular Regulation during Hemodialysis

BACKGROUND/AIMS: Lowering dialysate temperature to increase intradialytic hemodynamic stability may interfere with the ultrafiltration-dependent intradialytic autonomic cardiovascular regulation. The present study aimed to investigate hemodynamic and autonomic responses depending on dialysate temperature and the presence of diabetes. METHODS: Seventeen (8 diabetic, 9 non-diabetic) hypotension-resistant patients were alternately treated at dialysate temperatures of 37 and 35 degrees C. Hemodynamic parameters, heart rate variability (HRV) and baroreceptor reflex sensitivity (BRRS) were measured noninvasively. Power spectral analysis of HRV was used to evaluate cardiac sympathetic and parasympathetic activity. RESULTS: In contrast to diabetic patients who showed an overall reduced autonomic activity and a blunted autonomic response, in non-diabetic patients cardiac sympathetic activity increased during dialysis (p < 0.05) resulting in a shift in sympathovagal balance towards sympathetic predominance. This response was not altered by dialysate temperature. Significant decreases in stroke volume and cardiac output were found in both patient groups. Total peripheral resistance increased in diabetic (p < 0.05) and in non-diabetic patients (p < 0.01) at both dialysate temperatures. No differences in BRRS were determined. CONCLUSION: The presence of diabetes has great impact on the cardiovascular autonomic regulation during hemodialysis. Varying the dialysate temperature does not influence cardiovascular autonomic regulation in hemodynamically stable diabetic and non-diabetic patients.