An observational study of microcirculation in dialysis patients and kidney transplant recipients.

BACKGROUND: Microcirculatory dysfunction contributes to acute and chronic kidney diseases. To the best of our knowledge, no study has compared differences in microcirculation among healthy volunteers, dialysis patients and kidney transplant recipients.

MATERIALS AND METHODS: Sublingual microcirculation was examined using sidestream dark field imaging and was compared among 90 healthy volunteers, 40 dialysis patients and 40 kidney transplant recipients. The gender effect on microcirculation and the correlations among the microcirculation parameters, age, body mass index, heart rate and blood pressure were analysed.

RESULTS: Total small vessel density, perfused small vessel density and the proportion of perfused small vessels were lower in the dialysis patients than in the healthy volunteers and kidney transplant recipients [total small vessel density; healthy volunteers vs. dialysis patients vs. kidney transplant recipients, 25·2 (2·3) vs. 22·8 (2·6) vs. 24·2 (2·9) mm/mm2 , P < 0·001]. Systolic blood pressure showed a weak negative correlation with the microvascular flow index scores in the healthy volunteers. By contrast, systolic blood pressure, diastolic blood pressure and mean arterial pressure showed weak positive correlations with proportion of perfused small vessels and the microvascular flow index scores in the dialysis patients.

CONCLUSIONS: Microcirculatory dysfunction is noted in dialysis patients, and this alteration is ameliorated in KT recipients. The positive correlation between blood pressure and microcirculation in dialysis patients suggests that additional studies should investigate the optimal goal of blood pressure management for dialysis patients.