Assessment of nailfold microcirculation in non-dialysis CKD: Capillaroscopic indicators correlated with renal dysfunction

Chronic kidney disease (CKD) is commonly associated with vascular injury. To date, efficient tools for assessing microcirculatory changes in non-dialysis CKD patients remain limited. We conducted a retrospectively registered study to employed nailfold capillaroscopy as a non-invasive method to evaluate peripheral microcirculation in CKD. A total of 104 participants were enrolled, including 63 patients with non-dialysis CKD patients (CKD group) and 41 healthy controls (control group). Renal function assessment and nailfold microcirculation examinations were performed for all participants. We analyzed 20 microcirculatory parameters and further explored their associations with serum creatinine (Scr), blood urea nitrogen (BUN), cystatin C, estimated glomerular filtration rate (eGFR), CKD stage, and hemoglobin (Hb) within the CKD group. Results showed that serum creatinine, cystatin C, and CKD stage were independently and positively associated with the capillary number integral, whereas eGFR and hemoglobin were independently and negatively associated with the capillary number integral. In addition, serum creatinine, cystatin C, and CKD stage were independently and negatively associated with the subpapillary venular plexus integral, while eGFR was independently and positively associated with the subpapillary venular plexus integral. In summary, our findings suggest that several key renal function parameters are independently associated with capillary number integral and subpapillary venular plexus integral. These findings indicate that renal dysfunction may be associated with reduced capillary number and impaired subpapillary venous plexus relaxation in patients with non-dialysis CKD.