Association between visceral fat accumulation and decline in the estimated glomerular filtration rate based on cystatin C in the Japanese urban population: the KOBE study

Lower glomerular filtration rate after mild stroke induces cognitive impairment by causing endothelial dysfunction

The incidence of post stroke cognitive impairment (PSCI) is high in patients with mild stroke (MIS), and the risk factors and mechanism are uncertain. Increased cystatin C (CysC) levels after stroke may reflect lower glomerular filtration rate (GFR) and renal impairment. Previous studies have suggested endothelial dysfunction (ED) is closely related to renal impairment and cognitive impairment, respectively. We aimed to observe whether lower GFR estimated by CysC after MIS leaded to a high incidence of PSCI, and the role of ED in this process. 256 patients were enrolled in this prospective observational study. Renal function was assessed using GFR estimated by serum CysC. Endothelial function was evaluated by reactive hyperemia index (RHI) which calculated automatically by peripheral arterial tonometry (PAT). The cognitive function at baseline and 3 months was evaluated by MoCA score, and MoCA score ≤ 26 indicates the presence of PSCI. Spearman correlation analysis and linear regression were conducted to explore the factors affecting ED. Univariate and multivariate analysis was used to identify the independent risk factors of PSCI. The receiver operating characteristic (ROC) curve was applied to explore the optimal cutoff value of the independent risk factors levels for predicting PSCI. A total of 141 patients (55.1%) suffered from ED. Multiple linear regression analysis showed that there was a strong linear correlation between eGFRcys and RHI (p < 0.001). At the three-month follow-up, a total of 150 (58.6%) patients had been diagnosed with PSCI. Multivariate logistic regression analysis showed that RHI was an independent factor affecting the occurrence of PSCI (p < 0.05). ROC curve showed that the area under the curve was 0.724, and the optimal cut-off value of RHI was 1.655, with the sensitivity and specificity for PSCI were 72.7% and 73.6%, respectively. The lower eGFRcys level after MIS was significantly associated with ED, and ED may mediate the higher incidence of PSCI at 3 months after MIS.

Cystatin C for kidney function assessment in patients with facioscapulohumeral muscular dystrophy

BACKGROUND AND AIMS

Muscle mass (MM) impairment observed in facioscapulohumeral muscular dystrophy (FSHD) may bias estimated glomerular filtration rate (eGFR) based on creatinine (eGFRcreat). eGFR based on cystatin C (eGFRcys), produced by all nucleated cells, should be an interesting alternative. Main objectives were to compare eGFRcreat and eGRFcys for chronic kidney disease (CKD) staging and for annual eGFR evolution. Secondary objective was to analyse creatinine, cystatin C with measured MM.

MATERIAL AND METHODS

During 4 years, 159 FSHD patients having one or more creatinine and cystatin C measurements (total samples: n=379), with MM determination by bio-impedancemetry during their follow-up were included. eGFR were determined with CKD-Epi and EKFC equations.

RESULTS

On first examination samples, mean eGFRcys was significantly lower than mean eGFRcreat of 25.5 and 17.9 ml/min/1.73m² using CKD-Epi and EKFC equations, respectively. 53.5% (CKD-Epi) and 59.1% (EKFC) of agreement were obtained when using eGFRcys instead of eGFRcreat with reclassifications occurring mainly towards more severe stages. Age was correlated with cystatin C but not with creatinine, MM was correlated with creatinine but not with cystatin C. eGFR decreases >1 ml/min/1.73m² were more important when using eGFRcys instead of eGFRcreat (CKD-Epi: 37.5 vs 15.4%, p<0.001; EKFC: 34.6 vs 20.2%, p<0.01).

CONCLUSION

Cystatin C which is independent of MM appears as a promising candidate biomarker for CKD diagnosis and follow-up in FSHD patient.