Association between serum cystatin C levels and the severity or potential risk factors of acute ischemic stroke

Serum cystatin C and stroke risk: a national cohort and Mendelian randomization study

Purpose

The debate over the causal and longitudinal association between cystatin C and stroke in older adults persists. Our aim was to assess the link between cystatin C levels, both measured and genetically predicted, and stroke risk.

Methods

This study employed a retrospective cohort design using samples of the China Health and Retirement Longitudinal Study (CHARLS), which is a nationally representative cohort recruiting individuals aged 45 years or above. A multivariate logistic model and the two-sample Mendelian randomization framework were used to investigate the longitudinal and genetically predicted effect of serum cystatin C on stroke.

Results

The study population had a mean age of 59.6 (SD ±9.5), with 2,996 (46.1%) women. After adjusting for confounding factors, compared to those in the first quartile of cystatin C, those in the last quartile had the greatest risk of stroke incidence [odds ratio (OR), 1.380; 95% confidence interval (CI), 1.046-1.825]. The Mendelian randomization analysis showed that a genetically predicted cystatin C level was positively associated with total stroke (OR by inverse variance-weighted method, 1.114; 95% CI, 1.041-1.192).

Conclusions

This national cohort study suggests that higher serum cystatin C is associated with an increased risk of total stroke, which is further supported by Mendelian randomization.

Serum Cystatin C Predicts Stroke Clinical Outcomes at 1 Year Independent of Renal Function

Objective: Serum cystatin C (CysC) is a sensitive marker of renal function to predict cardiovascular diseases. We aimed to investigate the predictive value of CysC for clinical outcomes independent of renal function in patients with acute ischemic stroke (AIS).

Methods: We measured serum CysC levels in 10,256 AIS patients from Third China National Stroke Registry (CNSR-III). The primary outcome was a combination of all-cause mortality and major disability (modified Rankin scale score, 3–6). Secondary outcomes included stroke recurrence and combined vascular events at 1 year. Outcomes were analyzed using logistic regression and Cox proportional hazards models, respectively.

Results: The median CysC of included patients was 0.95 mg/l (interquartile range, 0.83–1.10 mg/l). A U-shaped association was observed between CysC and primary outcome (all-cause mortality or major disability) [quartile (Q)1 vs. Q2: adjusted odds ratio (aOR) 1.29, 95% CI 1.06–1.58, p = 0.012; Q3 vs. Q2: aOR 1.12, 95% CI 0.93–1.35, p = 0.242; Q4 vs. Q2: aOR 1.35, 95% CI 1.10–1.65, p = 0.004]. A similar trend also existed in “preserved renal function” patients. Adding CysC to a model containing conventional risk factors improved the model performance with integrated discrimination improvement (IDI) of 0.13% (p = 0.016) and net reclassification index (NRI) of 13.10% (p <0.001) for primary outcome. No significant association was observed for stroke recurrence or combined vascular event rate in different CysC quartiles.

Conclusions: CysC showed a U-shaped correlation with 1-year stroke clinical outcome, suggesting that serum CysC may not only be a simple candidate marker of renal function.

Genetics of 35 blood and urine biomarkers in the UK Biobank

Clinical laboratory tests are a critical component of the continuum of care. We evaluate the genetic basis of 35 blood and urine laboratory measurements in the UK Biobank (n = 363,228 individuals). We identify 1,857 loci associated with at least one trait, containing 3,374 fine-mapped associations and additional sets of large-effect (>0.1 s.d.) protein-altering, human leukocyte antigen (HLA) and copy number variant (CNV) associations. Through Mendelian randomization (MR) analysis, we discover 51 causal relationships, including previously known agonistic effects of urate on gout and cystatin C on stroke. Finally, we develop polygenic risk scores (PRSs) for each biomarker and build 'multi-PRS' models for diseases using 35 PRSs simultaneously, which improved chronic kidney disease, type 2 diabetes, gout and alcoholic cirrhosis genetic risk stratification in an independent dataset (FinnGen; n = 135,500) relative to single-disease PRSs. Together, our results delineate the genetic basis of biomarkers and their causal influences on diseases and improve genetic risk stratification for common diseases.

Prognostic Value of Cystatin C in Acute Ischemic Stroke Patients with Intravenous Thrombolysis

BACKGROUND

Less is known about the prognostic value of serum cystatin C in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT). The aim of the present study was to examine the association between serum cystatin C levels and prognosis of AIS patients after IVT.

METHODS

Serum cystatin C was measured within 24 hours after recombinant tissue plasminogen activator (rt-PA) treatment in 280 consecutively recruited patients with AIS. The main outcomes included combination of death and major disability, death, major disability (modified Rankin Scale score 3-5) and vascular events at 3-month follow-up.

RESULTS

During the 3-month follow-up, 94 patients (33.6%) experienced death or major disability (28 deaths and 66 major disability) and 49 patients (17.5%) experienced vascular events. After multivariate adjustment, serum cystatin C was significantly associated with an increased risk of the combined outcome of death and major disability (OR=4.51, P = 0.006). Adding serum cystatin C quartiles to a model containing conventional risk factors improved the predictive power for the combined outcome of death and major disability (continuous net reclassification index 43.88%, P < 0.001; categorical net reclassification index 9.15%, P = 0.013; integrated discrimination improvement 2.31%, P = 0.025). Similar phenomena were also observed in major disability and vascular events.

CONCLUSION

Higher levels of serum cystatin C in AIS patients after IVT were independently associated with increased risks of poor functional outcomes and vascular events, especially combining conventional risk factors, suggesting that serum cystatin C might improve risk prediction for poor prognosis in AIS patients receiving rt-PA treatment.

Association Between Cystatin C and the Risk of Ischemic Stroke: a Systematic Review and Meta-analysis

Ischemic stroke is a disease that affects people^'s health and quality of life. Cystatin C has been found as a new biomarker of cardiovascular disease. We performed this meta-analysis to assess the relationship between cystatin C and the risk of ischemic stroke. The studies on looking at the association between cystatin C and ischemic stroke were identified from inception to November 18, 2018. We performed a random-effects meta-analysis using mean difference. Nine studies with a total of 3773 ischemic stroke patients were included into the meta-analysis. Our results showed that patients with ischemic stroke had significantly higher serum cystatin C concentrations compared with the participants without ischemic stroke (pooled mean difference, 0.11; 95% confidence interval (CI), 0.00-0.22; P = 0.04), in particular acute ischemic stroke and subclinical cerebral infarction (mean difference, 0.23; 95% CI, 0.11-0.36; P = 0.0003 and mean difference, 0.07; 95% CI, 0.05-0.09; P < 0.00001, respectively). Cystatin C was associated with ischemic stroke, and it could be considered a predictor for the risk of ischemic stroke, especially in acute ischemic stroke and subclinical cerebral infarction.

From Analysis of Ischemic Mouse Brain Proteome to Identification of Human Serum Clusterin as a Potential Biomarker for Severity of Acute Ischemic Stroke

Ischemic stroke is a devastating neurological disease that can cause permanent brain damage, but to date, few biomarkers are available to reliably assess the severity of injury during acute onset. In this study, quantitative proteomic analysis of ischemic mouse brain detected the increase in expression levels of clusterin (CLU) and cystatin C (CST3). Since CLU is a secretary protein, serum samples (n = 70) were obtained from acute ischemic stroke (AIS) patients within 24 h of stroke onset and together with 70 matched health controls. Analysis of CLU levels indicated significantly higher levels in AIS patients than healthy controls (14.91 ± 4.03 vs. 12.79 ± 2.22 ng/L; P = 0.0004). Analysis of serum CST3 also showed significant increase in AIS patients as compared with healthy controls (0.90 ± 0.19 vs. 0.84 ± 0.12 ng/L; P = 0.0064). The serum values of CLU were also positively correlated with the NIH Stroke Scale (NIHSS) scores, the time interval after stroke onset, as well as major stroke risk factors associated with lipid profile. These data demonstrate that elevated levels of serum CLU and CST3 are independently associated with AIS and may serve as peripheral biomarkers to aid clinical assessment of AIS and its severity. This pilot study thus contributes to progress toward preclinical proteomic screening by using animal models and allows translation of results from bench to bedside.