Autonomic insufficiency as a factor contributing to dialysis-induced hypotension

Background. Autonomic insufficiency is considered a factor that contributes to dialysis-induced hypotension (DIH). However, the relationship between the two conditions has not been fully elucidated. Methods. We investigated 44 haemodialysis patients using [¹²³I]-meta-iodobenzylguanidine (MIBG) scintigraphy and power-spectral analysis (PSA) of heart rate variability. The patients were divided into four groups: a diabetic group with DIH, a diabetic group without DIH, a non-diabetic group with DIH, and a non-diabetic group without DIH. In these groups the heart to mediastinum average count rate (H/M), MIBG washout rate, and low- and high-frequency components of PSA were compared. Results. From the [¹²³I]-MIBG scintigraphy, for both early and delayed images, H/M of the groups with DIH were lower than in groups without DIH, in both diabetics and non-diabetics (P < 0.05). For the early images, H/M of the diabetic groups were lower than in the non-diabetic groups, in the groups both with and without DIH (P < 0.01). For the delayed images, H/M of the diabetic group was lower than in the non-diabetic group, in the groups with DIH (P < 0.05). The MIBG washout rate was the highest in the diabetic group with DIH (P < 0.05 vs diabetic and non-diabetic groups without DIH). The PSA of heart rate variability showed a good discrimination of the low-frequency component between the non-diabetic patients with and without DIH (P < 0.05). Mean ultra-filtration volume and its rate were not different among the four groups. Conclusion. Autonomic insufficiency is more severe in patients with DIH than in those without, and its degree may be enhanced in diabetic patients. For the management of DIH, special care should be addressed not only to dry weight but also to autonomic insufficiency.