The effect of short-term remote ischemic preconditioning on endothelial function of patients with chronic kidney disease: A randomized pilot study.

AIM: Patients with chronic kidney disease (CKD) are more susceptible to endothelial dysfunction and cardiovascular disease (CV). Remote ischemic preconditioning (rIPC) has been proven efficient in improving endothelial function and lowering the risk of CV. However, the safety and effect of rIPC on endothelial function in patients with CKD have not been effectively assessed. METHODS: 45 patients with CKD (average estimated glomerular filtration rate: 48.4 mL/min/1.73 m2) were randomly allocated to either 7-day daily upper-arm rIPC (4 × 5 min 200 mmHg, interspaced by 5-min reperfusion) or control (4 × 5 min 60 mmHg, interspaced by 5-min reperfusion). Vascular endothelial function was assessed by natural log-transformed reactive hyperemia index (LnRHI) before and after a 7-day intervention. Arterial elasticity was assessed by augmentation index (AI). RESULTS: The results showed that LnRHI could be improved by rIPC treatment (Pre = 0.57 ± 0.04 vs. Post = 0.67 ± 0.04, p = .001) with no changes relative to control (Pre = 0.68 ± 0.06 vs. Post = 0.64 ± 0.05, p = .470). Compared with the control group, the improvement of LnRHI was greater after rIPC treatment (rIPC vs. Control: 0.10 ± 0.03 vs. -0.04 ± 0.06, between-group mean difference, -0.15 [95% CI, -0.27 to -0.02], p = .027), while there was no significant difference in the change of AI@75 bpm (p = .312) between the two groups. CONCLUSION: RIPC is safe and well tolerated in patients with CKD. This pilot study suggests that rIPC seems to have the potential therapeutic effect to improve endothelial function. Of note, further larger trials are still warranted to confirm the efficacy of rIPC in improving endothelial function in CKD patients.

Association between sarcopenia and frailty in elderly patients with chronic kidney disease.

BACKGROUND: Frailty and sarcopenia are prevalent in chronic kidney disease (CKD) populations and could increase the risk for adverse health outcomes. Few studies assess the correlation between frailty, sarcopenia and CKD in non-dialysis patients. Therefore, this study aimed to determine frailty-associated factors in elderly CKD stage I-IV patients, expected to early identify and intervene in the frailty of elderly CKD patients. METHODS: A total of 774 elderly CKD I-IV patients (>60 years of age) recruited from 29 clinical centers in China between March 2017 and September 2019 were included in this study. We established a Frailty Index (FI) model to evaluate frailty risk and verified the distributional property of FI in the study population. Sarcopenia was defined according to the criteria of the Asian Working Group for Sarcopenia 2019. Multinomial logistic regression analysis was used to assess the associated factors for frailty. RESULTS: Seven hundred seventy-four patients (median age 67 years, 66.0% males) were included in this analysis, with a median estimated glomerular filtration rate of 52.8 mL/min/1.73 m2 . The prevalence of sarcopenia was 30.6%. The FI exhibited a right-skewed distribution. The age-related slope of FI was 1.4% per year on a logarithmic scale (r2  = 0.706, 95% CI 0.9, 1.8, P < 0.001). The upper limit of FI was around 0.43. The FI was related to mortality (HR = 1.06, 95% CI 1.00, 1.12, P = 0.041). Multivariate multinomial logistic regression analysis showed that sarcopenia, advanced age, CKD stage II-IV, low level of serum albumin and increased waist-hip ratio were significantly associated with high FI status, while advanced age and CKD stage III-IV were significantly associated with for median FI status. Moreover, the results from the subgroup were consistent with the leading results. CONCLUSIONS: Sarcopenia was independently associated with an increased risk for frailty in elderly CKD I-IV patients. Patients with sarcopenia, advanced age, high CKD stage, high waist-hip ratio and low serum albumin level should be assessed for frailty.

Urinary miR-16-5p can be used as a potential marker of endocapillary hypercellularity in IgA nephropathy.

The most prevalent primary glomerulonephritis and leading cause of end-stage renal disease worldwide is IgA nephropathy (IgAN). More and more studies are describing urinary microRNA (miRNA) as a non-invasive marker for a variety of renal diseases. We screened candidate miRNAs based on data from three published IgAN urinary sediment miRNAs chips. In separate confirmation and validation cohorts, we included 174 IgAN patients, 100 patients with other nephropathies as disease controls (DC), and 97 normal controls (NC) for quantitative real-time PCR. A total of three candidate miRNAs, miR-16-5p, Let-7g-5p, miR-15a-5p were obtained. In both the confirmation and validation cohorts, these miRNAs levels were considerably higher in the IgAN than in NC, with miR-16-5p significantly higher than in DC. The area under the ROC curve for urinary miR-16-5p levels was 0.73. Correlation analysis suggested that miR-16-5p was positively correlated with endocapillary hypercellularity (r = 0.164 p = 0.031). When miR-16-5p was combined with eGFR, proteinuria and C4, the AUC value for predicting endocapillary hypercellularity was 0.726. By following the renal function of patients with IgAN, the levels of miR-16-5p were noticeably higher in the IgAN progressors than in the non- progressors (p = 0.036). Urinary sediment miR-16-5p can be used as noninvasive biomarkers for the assessment of endocapillary hypercellularity and diagnosis of IgA nephropathy. Furthermore, urinary miR-16-5p may be predictors of renal progression.