Cystatin C and cardiovascular or all-cause mortality risk in the general population: A meta-analysis

Mediterranean diet and a health behavior index in relation to cardiovascular biomarkers: Data from the Health and Retirement Study

BACKGROUND AND AIM

Although lifestyle factors have been repeatedly examined for their role on cardiovascular diseases, their composite effect has not been frequently explored. We aimed to investigate the relation of dietary patterns (DPs) and a health behavior index (HBI) with cardiovascular biomarkers.

METHODS AND RESULTS

A cross-sectional analysis with data from 3461 US residents, participants in the Health and Retirement Study (HRS), was performed. Nutritional data were obtained with a food frequency questionnaire, while adherence to Mediterranean Diet (MD) was determined by the Mediterranean Diet Score. A posteriori DPs were estimated using principal component analysis and the HBI was constructed combining adherence to MD, smoking status, physical activity levels, alcohol consumption and body mass index. Multiple linear regression models were performed to examine the relation between DPs or HBI and levels of C-reactive protein (CRP), glycosylated hemoglobin (HbA1C), cystatin C (Cys C), total cholesterol (TC), high density lipoprotein (HDL) and TC:HDL in blood. Multiple linear regression showed that the "healthy" DP and the MD had a significant negative association with CRP and Cys C (p < 0.05), while the "Western-type" DP had a significant positive association with TC:HDL ratio, CRP and Cys C. Moreover, the HBI was positively associated with HDL (p < 0.05) and negatively associated with TC:HDL ratio, CRP and Cys C (p < 0.05).

CONCLUSIONS

Adherence to MD and to a healthy dietary pattern was negatively associated with biomarkers of inflammation, while the HBI was associated with a better cardiometabolic profile, assessed with blood biomarkers.

Biological age estimation using circulating blood biomarkers

Biological age captures physiological deterioration better than chronological age and is amenable to interventions. Blood-based biomarkers have been identified as suitable candidates for biological age estimation. This study aims to improve biological age estimation using machine learning models and a feature-set of 60 circulating biomarkers available from the UK Biobank (n = 306,116). We implement an Elastic-Net derived Cox model with 25 selected biomarkers to predict mortality risk (C-Index = 0.778; 95% CI [0.767-0.788]), which outperforms the well-known blood-biomarker based PhenoAge model (C-Index = 0.750; 95% CI [0.739-0.761]), providing a C-Index lift of 0.028 representing an 11% relative increase in predictive value. Importantly, we then show that using common clinical assay panels, with few biomarkers, alongside imputation and the model derived on the full set of biomarkers, does not substantially degrade predictive accuracy from the theoretical maximum achievable for the available biomarkers. Biological age is estimated as the equivalent age within the same-sex population which corresponds to an individual's mortality risk. Values ranged between 20-years younger and 20-years older than individuals' chronological age, exposing the magnitude of ageing signals contained in blood markers. Thus, we demonstrate a practical and cost-efficient method of estimating an improved measure of Biological Age, available to the general population.

Association of serum cystatin C level with coronary atherosclerotic plaque burden: a comprehensive analysis of observational studies and genetic study

BACKGROUND AND AIMS

Epidemiological studies show that high circulating cystatin C is associated with risk of cardiovascular disease (CVD), independent of creatinine-based renal function measurements. However, the relationship between serum cystatin C level and coronary atherosclerotic plaque burden is limited. We aimed to evaluate the relationship between circulating cystatin C and coronary atherosclerotic plaque burden.

METHODS

This study was a cross-sectional study based on China community population. Measurements of plaque burden were based on the segment-involvement score (SIS) and segment stenosis score (SSS), which derived from the Coronary Artery Tree Model Depicting Coronary Artery Plaque Scores. Logistic regression model was used to demonstrate the association between cystatin C level and coronary artery plaque burden. Mendelian randomization (MR) analyses were conducted to assess the causal effect of cystatin C level on coronary atherosclerosis risk.

RESULTS

A total of 3,043 objects were included in the present study. The odds risks (OR) of severe plaque burden in the highest serum cystatin C levels (OR: 2.50; Cl:1.59-3.91; P < 0.001) and medium-level cystatin C levels (OR: 1.86; 95% Cl: 1.21-2.88; P = 0.005) were significantly higher after fulled adjusted confounders compared with the lowest levels of serum cystatin C by SSS. The MR analysis showed that genetic predicted cystatin C levels was associated with an increased risk of coronary atherosclerosis (OR, 1.004; 95% CI, 1.002-1.006, P < 0.001) .

CONCLUSION

Elevated serum cystatin C levels were associated with coronary atherosclerotic plaque burden. Cystatin C levels had a causal effect on an increased risk of coronary atherosclerosis at the genetic level. WHAT IS ALREADY KNOWN ON THIS TOPIC?: Coronary artery disease is currently the most common cardiovascular disease and the leading global cause of mortality. Previous studies reported that higher serum cystatin C levels were associated with an increased risk for future cardiovascular events, independent of the normal creatinine levels or estimated glomerular filtration rate (eGFR) values. The presence of high-risk coronary atherosclerotic plaque burden is associated with increased risk of cardiovascular events. However, the association between serum cystatin C and coronary atherosclerotic plaque burden is not very clear. WHAT THIS STUDY ADDS?: Our study demonstrated that the elevated serum cystatin C levels were associated with coronary atherosclerotic plaque burden. In addition, we found that serum cystatin C levels had a causal effect on an increased risk of coronary atherosclerosis at the genetic level. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY?: Current research finds that serum cystatin C levels were associated with coronary atherosclerosis. The metabolic pathway of cystatin C could be a target for new therapies against CAD.

No causal association between plasma cystatin C and cardiovascular diseases: Mendelian randomization analyses in UK biobank

Background

We aimed to determine whether the plasma cystatin C is a causal risk factor for cardiovascular events, stroke, myocardial infarction (MI), and cardiovascular disease (CVD) mortality by conducting Mendelian randomization (MR) designs.

Methods

Our study included 277,057 individuals free of CVDs or cancer at baseline in the UK Biobank. The genetic scores of plasma cystatin C comprising 67 single-nucleotide polymorphisms were calculated on the basis of data from a large genome-wide association study. By stratifying the genetic score, we conducted cox regression to assess the relationship between plasma cystatin C and CVDs. In this study, linear MR analysis was used to estimate the causal association between plasma cystatin C and CVDs.

Results

Observational analyses showed that plasma cystatin C concentrations were associated with the risk of CVDs [hazard ratios (HR) per standard deviation (SD) 1.09, 95% confidence interval (CI); 1.07-1.10] and CVD mortality (1.14, 1.11-1.17). Among CVDs, plasma cystatin C were associated with stroke (1.10, 1.08-1.11) and MI (1.08, 1.07-1.10). Linear MR analysis did not provide evidence of a causal association between plasma cystatin C and the risk of CVDs [odds ratio (OR) per SD 0.96, 95% CI;0.90-1.03], stroke (0.96, 0.93-1.01), MI (0.97, 0.91-1.03), and CVD mortality (0.98, 0.96-1.01), with consistent estimates from sensitivity analyses.

Conclusion

Observational findings indicated that higher plasma cystatin C is associated with a higher risk of CVDs; According to MR studies, there is no causal association between plasma cystatin C and the risk of CVDs and CVD mortality.

GFR estimated with creatinine rather than cystatin C is more reflective of the true risk of adverse outcomes with low GFR in kidney transplant recipients

BACKGROUND

Serum cystatin C-based estimated glomerular filtration rate (eGFRcys) generally associates with clinical outcomes better than serum creatinine-based eGFR (eGFRcr) despite similar precision in estimating measured GFR (mGFR). We sought to determine whether the risk of adverse outcomes with eGFRcr or eGFRcys was via GFR alone or also via non-GFR determinants among kidney transplant recipients.

METHODS

Consecutive adult kidney transplant recipients underwent a standardized GFR assessment during a routine follow-up clinic visit between 2011 and 2013. Patients were followed for graft failure or the composite outcome of cardiovascular (CV) events or mortality through 2020. The risk of these events by baseline mGFR, eGFRcr and eGFRcys was assessed unadjusted, adjusted for mGFR and adjusted for CV risk factors.

RESULTS

There were 1135 recipients with a mean baseline mGFR of 55.6, eGFRcr of 54.8 and eGFRcys of 46.8 ml/min/1.73 m2 and a median follow-up of 6 years. Each 10 ml/min/1.73 m2 decrease in mGFR, eGFRcr or eGFRcys associated with graft failure [hazard ratio (HR) 1.79, 1.68 and 2.07, respectively; P < .001 for all) and CV events or mortality outcome (HR 1.28, 1.19 and 1.43, respectively; P < .001 for all). After adjusting for mGFR, eGFRcys associated with graft failure (HR 1.57, P < .001) and CV events or mortality (HR 1.49, P < .001), but eGFRcr did not associate with either. After further adjusting for CV risk factors, risk of these outcomes with lower eGFRcys was attenuated.

CONCLUSION

eGFRcr better represents the true relationship between GFR and outcomes after kidney transplantation because it has less non-GFR residual association. Cystatin C is better interpreted as a nonspecific prognostic biomarker than is eGFR in the kidney transplant setting.

Association of plasma cystatin C with all-cause and cause-specific mortality among middle-aged and elderly individuals: a prospective community-based cohort study

We investigated the associations of plasma cystatin C with all-cause and cause-specific mortality risk and identified potential modifying factors affecting these associations in middle-aged and elderly people (≥ 50 years). This community-based prospective cohort study included 13,913 individuals aged ≥ 50 years from the Health and Retirement Study. Cox proportional hazard models were used to estimate the associations between cystatin C concentrations and the risk of all-cause and cardiovascular and cancer mortality after adjustment for sociodemographic characteristics, lifestyle factors, self-reported medical history, and other potential confounding factors. During a total of 71,988 person-years of follow-up (median: 5.8 years; interquartile range 3.3-7.6 years), 1893 all-cause deaths were documented, including 714 cardiovascular-related and 406 cancer-related deaths. The comparisons of the groups with the highest (quartile 4) and lowest (quartile 1) cystatin C concentrations revealed that the adjusted hazard ratios and 95% confidence intervals were 1.92 (1.62-2.28) for all-cause mortality, 1.98 (1.48-2.65) for cardiovascular mortality, and 1.62 (1.13-2.32) for cancer mortality. The associations of cystatin C concentrations with all-cause, cardiovascular and cancer mortality did not differ substantially when participants were stratified by sex, age, BMI, current smoking status, current alcohol consumption, and regular exercise (all P for interactions > 0.05). Our study indicates that an elevated plasma cystatin C concentration is associated with an increased risk of all-cause, cardiovascular and cancer mortality both men and women among the middle-aged and elderly individuals.

Serum Cystatin-C is linked to increased prevalence of diabetes and higher risk of mortality in diverse middle-aged and older adults

Objective

Type 2 Diabetes Mellitus (henceforth diabetes) affects roughly 35 million individuals in the US and is a major risk factor for cardiovascular and kidney disease. Serum Cystatin-C is used to monitor renal function and detect kidney damage. Recent research has focused on linking Cystatin-C to cardiovascular risk and disease, but most findings focus on small sample sizes and generalize poorly to diverse populations, thus limiting epidemiological inferences. The aim of this manuscript is to study the association between Cystatin-C, diabetes, and mortality and test for possible sex or racial/ethnic background modifications in these relationships.

Methods

We analyzed 8-years of biennial panel data from Health and Retirement Study participants 50-years and older who self-identified as White (unweighted N (uN) = 5,595), Black (uN = 867), or Latino (uN = 565) for a total of uN = 7,027 individuals. We modeled diabetes and death over 8-years as function of baseline Cystatin-C (log transformed) adjusting for covariates and tested modifications in associations by race/ethnic background and sex.

Results

Mean log Cystatin-C at visit 1 was 0.03±0.32 standard deviation. A 10% increase in Cystatin-C levels was associated with 13% increased relative risk of diabetes at baseline (11% and 9% by years 4 and 8). A 10% increase in Cystatin-C was highly associated with increased relative risk of death (28% and 31% by years 4 and 8). These associations were present even after adjusting for possible confounders and were not modified by sex or racial/ethnic background.

Conclusion

Despite differential risks for diabetes and mortality by racial/ethnic groups, Cystatin-C was equally predictive of these outcomes across groups. Cystatin-C dysregulations could be used as a risk indicator for diabetes and as a warning sign for accelerated risk of mortality.

Serum cystatin C is associated with the prognosis in acute myocardial infarction patients after coronary revascularization: a systematic review and meta-analysis

Objective

Our study aimed to assess the association between serum cystatin C levels and prognosis in acute myocardial infarction (AMI) patients after coronary reconstructive surgery.

Methods

We searched PubMed, Embase, and Cochrane Library up to January 21, 2022 without language restriction. Outcomes were major cardiovascular events (MACEs) and mortality. The risk ratio (RR) and 95% confidence interval (CI) were merged by random-effect models.

Results

We included 8 studies with a total of 7,394 subjects in our meta-analysis. Our meta-analysis showed that higher-level of serum cystatin C levels were associated with higher risk of MACEs (RR = 2.52, 95% CI 1.63–3.89, P < 0.001) and mortality (RR = 2.64, 95% CI 1.66–4.19, P < 0.001) in AMI patients after coronary revascularization. Subgroup analysis showed that the serum cystatin C levels were associated with significantly higher risk of MACEs (RR = 2.72, 95% CI 1.32–5.60, P = 0.006) and mortality (RR = 2.98, 95% CI 1.21–7.37, P = 0.020) in AMI patients after percutaneous coronary intervention (PCI). However, in AMI patients after coronary artery bypass surgery, there were no significantly higher risk of MACEs (RR = 2.41, 95% CI 0.98–5.93, P = 0.05) and mortality (RR = 3.15, 95% CI 0.76–13.03, P = 0.10). Further subgroup analysis showed that this significantly higher risk of MACEs and mortality did not change with the study sample size, study population area or study follow-up time.

Conclusion

The meta-analysis demonstrated that higher serum cystatin C levels were associated with significantly higher risk of MACEs and mortality in AMI patients after PCI. It is a biomarker for risk stratification for predicting the prognosis in AMI patients after PCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02599-5.

OUP accepted manuscript

Background

Methods

Results

Conclusions

A nomogram based on serum cystatin C for predicting acute kidney injury in patients with traumatic brain injury

BACKGROUND

Acute kidney injury (AKI) is a common complication in traumatic brain injury (TBI) patients and is associated with unfavorable outcome of these patients. We designed this study to explore the value of serum cystatin C, an indicator of renal function, on predicting AKI after suffering TBI.

METHODS

Patients confirmed with TBI and hospitalized in the West China Hospital of Sichuan University between January 2015 and December 2019 were included. Patients were divided into two groups according to occurrence of AKI. Univariate and multivariate logistic regression analyses were sequentially utilized to find risk factors of AKI in included TBI patients. Nomogram composed of discovered risk factors for predicting AKI was constructed. Receiver operating characteristics (ROC) curves were drawn and area under the ROC curve (AUC) were calculated to evaluate the predictive value of cystatin C alone and the constructed nomogram.

RESULTS

Among 234 included TBI patients, 55 were divided into AKI group. AKI group had shorter length of stay (p < 0.001) and higher in-hospital mortality (p < 0.001). Multivariate logistic regression analysis showed absolute lymphocyte count (p = 0.034), serum creatinine (p < 0.001), serum cystatin C (p = 0.017) and transfusion of red blood cell (p = 0.005) were independently associated with development of AKI after TBI. While hypertonic saline use was not associated with the development of AKI (p = 0.067). The AUC of single cystatin C and predictive nomogram were 0.804 and 0.925, respectively.

CONCLUSION

Higher serum cystatin C is associated with development of AKI in TBI patients. Predictive nomogram incorporating cystatin C is beneficial for physicians to evaluate possibilities of AKI and consequently adjust treatment strategies to avoid occurrence of AKI.

Association between socioeconomic position and cystatin C in the Heinz Nixdorf Recall Study

Social inequalities in health and disease are well studied. Less information is available on inequalities in biomarker levels indicating subclinical stages of disease such as cystatin C, an early diagnostic marker of renal dysfunction and predictor for cardiovascular disease. We evaluated the relationship between cystatin C, socioeconomic position (SEP) and established cardiovascular risk factors in a population-based study. In 4475 men and women aged 45–75 years participating in the baseline examination of the Heinz Nixdorf Recall Study cystatin C was measured from serum samples with a nephelometric assay. SEP was assessed by education and household income. Linear regression models were used to analyse the association between SEP and cystatin C as well as the impact of cardiovascular risk factors (i.e., body mass index, blood pressure, blood glucose, diabetes mellitus, blood lipids, C-reactive protein, smoking) on this association. After adjustment for age and sex cystatin C decreased by 0.019 mg/l (95% confidence interval (CI) − 0.030 to − 0.008) per five years of education. While using a categorical education variable cystatin C presented 0.039 mg/l (95% CI 0.017–0.061) higher in men and women in the lowest educational category (≤ 10 years of education) compared to the highest category (≥ 18 years). Concerning income, cystatin C decreased by 0.014 mg/l (95% CI − 0.021 to − 0.006) per 1000 € after adjustment for age and sex. For men and women in the lowest income quartile cystatin C was 0.024 mg/l (95% CI 0.009–0.038) higher compared to the highest income quartile. After adjusting for established cardiovascular risk factors the observed associations were substantially diminished. Social inequalities seem to play a role in subclinical stages of renal dysfunction, which are also related to development of cardiovascular disease. Adjustment for traditional cardiovascular risk factors showed that these risk factors largely explain the association between SEP and cystatin C.

Nomogram for the Prediction of Intrahospital Mortality Risk of Patients with ST-Segment Elevation Myocardial Infarction Complicated with Hyperuricemia: A Multicenter Retrospective Study

Purpose

This study aimed to establish an accurate and easy predictive model for ST-segment elevation myocardial infarction (STEMI) patients with hyperuricemia, using readily available features to estimate intrahospital mortality risk.

Patients and Methods

This was a multicenter retrospective study involving the development of risk prediction models for intrahospital mortality among all STEMI patients with hyperuricemia from Zunyi Medical University Chest Pain Center’s specialized alliance between January 1, 2016 and June 30, 2020. The primary outcome was intrahospital mortality. A total of 48 candidate variables were considered from demographic and clinical data. The least absolute shrinkage and selection operator (LASSO) was used to develop a nomogram. Concordance index values, decision curve analysis, the area under the curve (AUC), and clinical impact curves were examined. In this study, 489 patients with STEMI were included in the training dataset and an additional 209 patients from the 44 chest pain centers were included in the test cohort. B-type natriuretic peptides, α-hydroxybutyrate dehydrogenase (α-HBDH), cystatin C, out-of-hospital cardiac arrest (OHCA), shock index, and neutrophil-to-lymphocyte ratio were associated with intrahospital mortality and included in the nomogram.

Results

The model showed good discrimination power, and the AUC generated to predict survival in the training set was 0.875 (95% confidence interval, 0.825–0.925). In the validation set, the AUC of survival predictions was 0.87 (95% confidence interval, 0.792–0.947). Calibration plots and decision curve analysis showed good model performance in both datasets. A web-based calculator (https://bzxzmu.shinyapps.io/STEMI-with-Hyperuricemia-intrahospital-mortality/) was established based on the nomogram model, which was used to measure the levels of OHCA, neutrophil-to-lymphocyte ratio, shock index, α-HBDH, cystatin C, and B-type natriuretic peptides.

Conclusion

For practical applications, this model may prove clinically useful for personalized therapy management in patients with STEMI with hyperuricemia.

Alexithymia is associated with increased all-cause mortality risk in men, but not in women: A 10-year follow-up study

OBJECTIVE

Alexithymia is associated with various mental as well as physical disorders. Some evidence also suggested high alexithymia to increase mortality risk, but these results are few and based on specific sample compositions. We aimed to investigate the impact of alexithymia on mortality risk in a large population based cohort. In addition, we sought to elucidate the effects of the subfactors of alexithymia and sex differences.

METHODS

In a sample of N = 1380 individuals from the Study of Health in Pomerania (SHIP), we investigated the hazard-ratio (HR) of alexithymia as obtained by the Toronto Alexithymia Scale-20 (TAS-20) on all-cause mortality over an average observation time of 10 years. Sex-by-TAS-20-interactions as well as sex-stratified analyses were performed.

RESULTS

Alexithymia was significantly associated with enhanced mortality risk (HR = 1.033; 95%-CI = 1.008-1.058); p = 0.009). While sex-by-TAS-20 interactions remained insignificant, sex-stratified analyses showed that this effect was only significant in men (HR = 1.050; 95%-CI = 1.022-1.079; p ≤ 0.001), but not in women (HR: 1.008; 95%-CI = 0.960-1.057; p = 0.76). The effect was validated for the "difficulties identifying feelings" (DIF) and "difficulties describing feelings" (DDF) subfactors of the TAS-20.

CONCLUSION

Our study supports and extents previous findings by indicating that mortality risk enhancing effects of alexithymia are specific to male subjects and validated for the DIF and DDF facets. Socioeconomic, clinical and metabolic factors were associated with this relationship. Finding that the impact of alexithymia remains stable in the fully adjusted models suggests that yet unidentified additional factors must be considered.

Level and Change in N-Terminal Pro-B-Type Natriuretic Peptide and Kidney Function and Survival to Age 90

BACKGROUND

Many traditional cardiovascular risk factors do not predict survival to very old age. Studies have shown associations of estimated glomerular filtration rate (eGFR) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) with cardiovascular disease and mortality in older populations. This study aimed to evaluate the associations of the level and change in eGFR and NT-pro-BNP with longevity to age 90 years.

METHOD

The population included participants (n = 3,645) in the Cardiovascular Health Study, aged between 67 and 75 at baseline. The main exposures were eGFR, calculated with the Berlin Initiative Study (BIS) 2 equation, and NT-pro-BNP, and the main outcome was survival to age 90. Mixed models were used to estimate level and change of the main exposures.

RESULTS

There was an association between baseline level and change of both eGFR and NT-pro-BNP and survival to 90, and this association persisted after adjustment for covariates. Each 10 mL/min/1.73 m2 higher eGFR level was associated with an adjusted odds ratio (OR) of 1.23 (95% CI: 1.13, 1.34) of survival to 90, and a 0.5 mL/min/1.73 m2 slower decline in eGFR was associated with an OR of 1.51 (95% CI: 1.31, 1.74). A twofold higher level of NT-pro-BNP level had an adjusted OR of 0.67 (95% CI: 0.61, 0.73), and a 1.05-fold increase per year in NT-pro-BNP had an OR of 0.53 (95% CI: 0.43, 0.65) for survival to age 90.

CONCLUSION

eGFR and NT-pro-BNP appear to be important risk factors for longevity to age 90.

Ultra-processed food consumption is associated with increased risk of all-cause and cardiovascular mortality in the Moli-sani Study

BACKGROUND

Consumption of ultra-processed food (UPF) is gaining growing attention in relation to disease/mortality risk, but less is known on the main nutritional factors or biological mechanisms potentially underlying such associations.

OBJECTIVES

We aimed to assess the association between UPF and mortality risk in a large sample of the Italian adult population and test which nutritional factors were on the pathway of this relation. Established risk factors for cardiovascular disease (CVD) were analyzed as potential biological mechanisms linking UPF to mortality.

METHODS

Longitudinal analysis was conducted on 22,475 men and women (mean ± SD age: 55 ± 12 y) recruited in the Moli-sani Study (2005-2010, Italy) and followed for 8.2 y. Food intake was assessed using a semiquantitative FFQ. UPF was defined using the NOVA classification according to degree of processing, and UPF intakes were categorized as quartiles of the ratio (%) of UPF (g/d) to total food consumed (g/d).

RESULTS

Individuals reporting the highest intake of UPF (Q4, >14.6% of total food), as opposed to the lowest (Q1, UPF < 6.6%), experienced increased risks of CVD mortality (HR: 1.58; 95% CI: 1.23, 2.03), death from ischemic heart disease (IHD)/cerebrovascular disease (HR: 1.52; 95% CI: 1.10, 2.09), and all-cause mortality (HR: 1.26; 95% CI: 1.09, 1.46). High sugar content explained 36.3% of the relation of UPF with IHD/cerebrovascular mortality, whereas other nutritional factors (e.g., saturated fats) were unlikely to be on the pathway. Biomarkers of renal function accounted for 20.1% of the association of UPF with all-cause mortality, and 12.0% for that of UPF with CVD mortality.

CONCLUSIONS

A high proportion of UPF in the diet was associated with increased risk of CVD and all-cause mortality, partly through its high dietary content of sugar. Some established biomarkers of CVD risk were likely to be on the pathway of such associations. These findings should serve as an incentive for limiting consumption of UPF, and encouraging natural or minimally processed foods, as several national nutritional policies recommend.

Association Between the Concentration and Rangeability of Cystatin C and Mortality of COVID-19 Patients With or Without Type 2 Diabetes Mellitus: A Retrospective Analysis

BACKGROUND

We investigated if the concentration and "rangeability" of cystatin C (CysC) influenced the prognosis of coronavirus disease 2019 (COVID-19) in patients suffering from, or not suffering from, type 2 diabetes mellitus (T2DM).

METHODS

A total of 675 T2DM patients and 572 non-T2DM patients were divided into "low" and "high" CysC groups and low and high CysC-rangeability groups according to serum CysC level and range of change of CysC level, respectively. Demographic characteristics, clinical data, and laboratory results of the four groups were analyzed.

RESULTS

COVID-19 patients with a high level and rangeability of CysC had more organ damage and a higher risk of death compared with those with a low level or low rangeability of CysC. Patients with a higher level and rangeability of CysC had more blood lymphocytes and higher levels of C-reactive protein, alanine aminotransferase, and aspartate aminotransferase. After adjustment for possible confounders, multivariate analysis revealed that CysC >0.93 mg/dL was significantly associated with the risk of heart failure (OR = 2.231, 95% CI: 1.125-5.312) and all-cause death (2.694, 1.161-6.252). CysC rangeability >0 was significantly associated with all-cause death (OR = 4.217, 95% CI: 1.953-9.106). These associations were stronger in patients suffering from T2DM than in those not suffering from T2DM.

CONCLUSIONS

The level and rangeability of CysC may influence the prognosis of COVID-19. Special care and appropriate intervention should be undertaken in COVID-19 patients with an increased CysC level during hospitalization and follow-up, especially for those with T2DM.

Cystatin C as a biomarker of chronic kidney disease: latest developments

INTRODUCTION

Chronic kidney disease (CKD) is common, occurring in over 10% of individuals globally, and is increasing in prevalence. The limitations of traditional biomarkers of renal dysfunction, such as serum creatinine, have been well demonstrated in the literature. Therefore, augmenting clinical assessment with newer biomarkers, such as serum cystatin C, has the potential to improve disease monitoring and patient care.

AREAS COVERED

The present paper assesses the utility and limitations of serum cystatin C as a biomarker for CKD in light of the current literature.

EXPERT OPINION

Serum cystatin C has been well established as an early and accurate biomarker of CKD that is particularly helpful in patients for whom creatinine is an inadequate marker or for whom more cumbersome methods of glomerular filtration rate (GFR) measurement are impractical. Current research questions are no longer focused on if, but rather when and how often cystatin C should be used in the evaluation of CKD patients. However, transition of all reagents and estimated GFR equations to the newly established International Standard is critical for developing generalizable data.

Association Between Cystatin C and Cardiac Function and Long-Term Prognosis in Patients with Chronic Heart Failure

BACKGROUND The aim of this study was to investigate the association between cystatin C and cardiac function and long-term prognosis in patients with chronic heart failure (CHF). MATERIAL AND METHODS We selected 418 CHF patients admitted to our hospital as subjects. Patients were divided into 3 groups according to the cystatin C level (Quantile 1 group: 0.65-1.04 mg/L, Quantile 2 group: 1.05-1.35 mg/L, and Quantile 3 group: 1.36-7.84 mg/L), and patients were followed up for 5 years. We used odds ratio (OR) and 95% confidence interval (CI) to compare the results. RESULTS The cystatin C and NT-ProBNP level in the cardiac function grade (NYHA) class IV group were higher than those in the class III group (P<0.05). Pearson correlation analysis showed that there was a positive correlation between cystatin C and NT-ProBNP log₁₀ transform in CHF patients (r=0.411). During 5-year follow-up, 231 patients died and the 5-year all-cause mortality rate was 55.26% (231/418). There was a significant difference in 5-year all-cause mortality among the 3 groups (P for trend=0.010). After adjusting for potential confounders by multivariate regression analysis, the Quantile 2 group vs. Quantile 1 group were OR=0.83, 95% CI 0.51 to 1.35, P=0.448, and the Quantile 3 group vs. Quantile 1 group were OR=1.71, 95% CI. 1.04 to 2.82, P=0.034. Curve fitting showed that cystatin C was positively correlated with 5-year all-cause mortality in CHF patients. CONCLUSIONS Cystatin C was positively correlated with cardiac function and NT-ProBNP in CHF patients. Cystatin C could be used as a serological index to evaluate the long-term prognosis of CHF patients.

Modulation of muscle protein synthesis by amino acids: what consequences for the secretome? A preliminary in vitro study

The modulation by amino acids of muscle secretome is largely unknown. In this study, we investigate the effect of hyperaminoacidemia or specific amino acids (citrulline or leucine) on protein synthesis and secretome in myotubes. All conditions stimulate muscle protein synthesis, and secretome is differently modulated depending of the amino acids considered. In conclusion, the activation of protein synthesis by amino acids induces different modulations of the muscle secretome, proposing a new role of amino acids in the regulation of muscle function.

Serum cystatin-c as predictive factor of preeclampsia: A meta-analysis of 27 observational studies

OBJECTIVE

Serum cystatin-c is a protein that is filtered freely through the glomerulus and reabsorbed and degraded by proximal tubular cells and can be used as a biomarker of renal function. Its levels rise during the third trimester and decrease in the postpartum period. The purpose of the present meta-analysis is to assess the performance of serum cystatin-c for the prediction of preeclampsia.

DESIGN AND METHODS

We used the Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar. We selected all observational studies (both prospective and retrospective) that investigated the accuracy of cystatin-c in predicting preeclampsia. Statistical meta-analysis was performed with the RevMan 5.3 and Stata/IC 13.0 software, using hierarchical models to develop the SROC curve.

RESULTS

The quantitative synthesis was based in 27 studies with a total number of 2,320 women. Serum cystatin-c levels were higher in preeclamptic women compared to healthy pregnant controls (MD: 0.40 mg/l, 95% CI [0.33, 0.46]). The pooled sensitivity of serum cystatin-c for the prediction of preeclampsia was 0.85 (95% CI [0.79-0.89]) and the pooled specificity 0.84 (95% CI [0.77-0.90]. Fagan's nomogram indicated that the post-test probability increased to 14% (positive test) and decreased to 1% (negative test), when the pre-test probability was set at 3%.

CONCLUSIONS

According to the findings of our study serum cystatin-c seems to be a promising biomarker for the detection of preeclampsia during the third trimester of pregnancy. Therefore, its implementation in future predictive models in the field is recommended.

Cystatin C for predicting all-cause mortality and rehospitalization in patients with heart failure: a meta-analysis

Circulating cystatin C (cys-C/CYC) has been identified as an independent predictor of all-cause mortality in patients with coronary artery disease and the general population. This meta-analysis aimed to systematically evaluate the association between elevated cys-C level and all-cause mortality and rehospitalization risk amongst patients with heart failure (HF). PubMed and Embase databases were searched until December 2017. All prospective observational studies that reported a multivariate-adjusted risk estimate of all-cause mortality and/or rehospitalization for the highest compared with lowest cys-C level in HF patients were included. Ten prospective studies involving 3155 HF patients were included. Meta-analysis indicated that the highest compared with lowest cys-C level was associated with an increased risk of all-cause mortality (hazard ratio (HR): 2.33; 95% confidence intervals (CI): 1.67-3.27; I²  = 75.0%, P<0.001) and combination of mortality/rehospitalization (HR: 2.06; 95%CI: 1.58-2.69; I²  = 41.6%, P=0.181). Results of stratified analysis indicated that the all-cause mortality risk was consistently found in the follow-up duration, cys-C cut-off value or type of HF subgroup. Elevated cys-C level is possibly associated with an increased risk of all-cause mortality and rehospitalization in HF patients. This increased risk is probably independent of creatinine or estimated glomerular filtration rate (eGFR).

Relationship of Postpartum Levels of Cystatin and High-Sensitivity C-Reactive Protein and Duration of Lactation in Mothers with Previous Gestational Hypertension or Preeclampsia

Background: Women with hypertensive disorders of pregnancy are at increased risk of cardiovascular disease in later life. We sought to determine the association between lactation and markers of maternal cardiovascular health among postpartum women with and without hypertensive disorders of pregnancy via measures of inflammation (high-sensitivity C-reactive protein [hsCRP]) and renal function (cystatin C). Materials and Methods: This prospective cohort study enrolled primarily overweight and obese women during early pregnancy. At a postpartum study visit occurring 6-24 months after delivery, we collected data on lactation duration and measured hsCRP and cystatin C. We assessed associations between lactation duration and levels of hsCRP and cystatin C among normotensive women and women with preeclampsia or gestational hypertension using analysis of variance and chi-squared tests. Linear regression models adjusted for age, race, education, prepregnancy body mass index, current smoking, and time since delivery. Results: Of 425 women, 37 (9%) had preeclampsia and 48 (11%) had gestational hypertension during enrollment pregnancy. The postpartum visit occurred at a mean of 8.6 ± 4.4 months after delivery. Women with a history of preeclampsia had significantly higher levels of cystatin C (mean 0.86 versus 0.78 mg/L; p = 0.03) compared with normotensive women, but nonsignificant elevation in hsCRP (mean 8.39 versus 6.04 mg/L; p = 0.08). Women with gestational hypertension had no differences in mean hsCRP or cystatin C compared with normotensive women. Among the 237 women with any lactation, 78 (18%) lactated for at least 6 months. Lactation duration both in the overall sample and among women with gestational hypertension or preeclampsia was not associated with levels of hsCRP or cystatin C. Conclusions: Preeclampsia history was associated with elevated postpartum levels of cystatin C; however, duration of lactation was not associated with postpartum hsCRP or cystatin C, regardless of history of gestational hypertension or preeclampsia. Further research is needed on mechanisms through which lactation may affect maternal risk of cardiovascular disease.

Risk of hypertension and abnormal biomarkers in the first year postpartum associated with hypertensive disorders of pregnancy among overweight and obese women

OBJECTIVES

Hypertension and obesity are common cardiometabolic risk factors in reproductive age women. The association of hypertensive disorders of pregnancy with later-life cardiovascular disease is well-established, however, it is unknown how obesity and hypertensive disorders of pregnancy converge to accelerate development of hypertension in the postpartum period. The aim of this study was to characterize rates of sustained hypertension at one year postpartum using the new American Heart Association/American College of Cardiology Guidelines among overweight and obese women with a normotensive pregnancy or hypertensive disorder of pregnancy.

STUDY DESIGN

315 early pregnant women were enrolled prospectively and followed up to 12 months after delivery (mean 7.0 ± 1.8 months). At a postpartum research visit, we measured blood pressure and collected blood samples to measure cystatin C and high sensitivity C-reactive protein.

RESULTS

A total of 254 women had a normotensive pregnancy, 39 had gestational hypertension (12.4%) and 22 had preeclampsia (7.0%). 91 women had hypertension at the postpartum study visit (28.9%). After adjustment for maternal age, BMI, lactation and time postpartum, preeclampsia was associated with an aOR 2.35 (95%CI 1.63-3.41) of development of sustained hypertension and an aOR 3.23 (95%CI 1.56-6.68) of hypertension with abnormal biomarkers compared to women with normotensive pregnancies.

CONCLUSIONS

We demonstrate a high prevalence of hypertension and abnormal biomarkers associated with hypertensive disorders of pregnancy among overweight and obese women. Our findings support the need for structured follow up and risk reduction in overweight and obese women with hypertensive disorders of pregnancy as early as the first year postpartum.

[Evaluation of nephrocerebral risk with the use of cystatin C in patients with chronic kidney disease]

AIM

To study a role of cystatin C in the nephrocerebral risk in chronic kidney disease at the initial stage of the disease.

MATERIAL AND METHODS

One hundred and twenty-eight patients (63 men and 65 women) with chronic kidney disease (CKD) were examined at the pre-dialysis stage of the disease. All patients underwent a complex clinical and laboratory examination with determination of the lipid spectrum, uric acid, fibrinogen, calcium and cystatin C, and subsequent calculation of the glomerular filtration rate (GFR). To assess structural changes in carotid arteries, ultrasound dopplerography was performed. Depending on the thickness of the intima-media (TIM), the entire sample is divided into CKD groups with no signs of carotid atherosclerosis (SC), n=70 and on CKD with SC, n=58.

RESULTS

Patients of the second group (CKD with SC), had higher body mass index (p<0.05), systolic (p<0.05) and central (p<0.05) arterial pressure (BP) and blood cystatin C (p<0.05). In the same group, there was a significant decrease in the concentration of high-density lipoprotein cholesterol (p<0.05) compared with those of the first group (CKD). The age of patients and the content of cystatin C (p<0.05) influenced the increase in TIM. Significant positive correlations between cystatin C content and TIM, systolic and diastolic blood pressure (p<0.05), and a negative correlation cystatin C content and GFR were noted in patients of the second group.

CONCLUSION

The increase in the level of cystatin C in blood plasma in CKD indicates the development of structural changes in the carotid arteries, the increase in the levels of systolic and central arterial pressure, the decrease in the concentration of HDL cholesterol, which is associated with significant inhibition of GFR.

Association Between Increased Levels of Cystatin C and the Development of Cardiovascular Events or Mortality: A Systematic Review and Meta-Analysis

BACKGROUND

Cystatin C seems promising for evaluating the risk of cardiovascular events and mortality.

OBJECTIVE

To evaluate the association between high levels of cystatin C and the development of cardiovascular events or mortality.

METHODS

The articles were selected in the Medline/PubMed, Web of Science, and Scielo databases. The eligibility criteria were prospective cohort observational trials that assessed the association of high serum levels of cystatin C with the development of cardiovascular events or mortality in individuals with normal renal function. Only studies that evaluated the mortality outcome compared the fourth with the first quartile of cystatin C and performed multivariate Cox's proportional hazard regression analysis were included in the meta-analysis. A p value < 0,05 was considered significant.

RESULTS

Among the 647 articles found, 12 were included in the systematic review and two in the meta-analysis. The risk of development of adverse outcomes was assessed by eight studies using the hazard ratio. Among them, six studies found an increased risk of cardiovascular events or mortality. The multivariate regression analysis was performed by six studies, and the risk of developing adverse outcomes remained significant after the analysis in four of these studies. The result of the meta-analysis [HR = 2.28 (1.70-3.05), p < 0.001] indicated that there is a significant association between high levels of cystatin C and the risk of mortality in individuals with normal renal function.

CONCLUSION

There is a significant association between high levels of cystatin C and the development of cardiovascular events or mortality in individuals with normal renal function.

Prognostic ability of cystatin C and homocysteine plasma levels for long-term outcomes in very old acute myocardial infarction patients

Background and aims

This study sought to evaluate the prognostic powers of combined use of cystatin C (Cys C) and homocysteine (Hcy) at predicting adverse events of patients >80 years old with acute myocardial infarction (AMI).

Patients and methods

The analysis involved 753 patients >80 years old undergoing coronary angiography for chest pain in China from January 2006 to December 2012. Kaplan–Meier method was used for survival and major adverse cardiac events (MACE) rates. Multivariate Cox regression was performed to identify mortality predictors. Receiver operating characteristic curve analysis was performed to predict the cutoff values of Cys C and Hcy for all-cause mortality.

Results

The duration of follow-up was 40–116 months (median, 63 months; interquartile range, 51–74 months). The long-term survival and event-free survival rates of AMI patients were significantly lower than those of unstable angina pectoris patients (P<0.05), and were significantly different according to the tertile concentration of Cys C of AMI patients (P<0.01). Cys C and Hcy were independent risk factors for long-term all-cause mortality (odds ratio [OR] =3.72 [2.27–6.09]; OR =1.59 [1.04–2.61]) and MACE (OR =2.83 [1.82–4.40]; OR =1.09 [1.04–1.21]) of AMI patients. The predictive cutoff value of Cys C was 1.815 mg/L (82.8%, 86.4%) and that of Hcy was 15.06 μmol/L (84.4%, 83.1%) in AMI patients. Combined use of both biomarker’s cutoff values further increased the sensitivity and specificity of all-cause mortality.

Conclusion

Cys C is a strong independent predictor of long-term all-cause death and MACE in very old AMI patients. The combined use of Cys C and Hcy further improves the predictive accuracy.

Impact of lean mass and bone density on glomerular filtration rate estimation in people living with HIV/AIDS

Context

Chronic kidney disease is a frequent complication in persons living with HIV/AIDS. Although previous studies have suggested that the CKD-EPI formula is appropriate to estimate glomerular filtration rate (GFR) in HIV-positive adults with normal kidney function, the optimal way to estimate GFR in those with Stage 3 chronic kidney disease is not known. Moreover, the impact of muscle mass on creatinine level and GFR estimation is unknown.

Aim and methods

Our study aimed to evaluate the accuracy of different diagnostic tests available compared to the gold standard measurement of GFR. A group of 44 HIV-1 patients with an estimated GFR between 60 and 30 ml/min/1.73 m² were included in a single-center cross-sectional study. Serum creatinine and cystatin C were measured. GFR was estimated using Cockcroft-Gault, MDRD, sMDRD, CKD-EPI, CKD-EPIcyst, and CKD-EPIcyst/creat formulae and was measured using isotopic Chrome₅₁ EDTA clearance. Bone density and muscle mass were measured by DXA scan.

Results

Mean age was 62±10 years. Mean BMI was 23±4 kg/m². Prevalence of diabetes was 30% and of hypertension was 47%. Viral load was <40 copies/ml for 90% of the patients, and mean CD₄ count was 446±191 cells/mm³. Mean measured GFR was 63.4±16.5 ml/min/1.73 m². All formulae under-estimated GFR. The best relative precision and accuracy were provided by the CKP-EPI formula. sMDRD, CKD-EPIcyst, and CKD-EPIcyst/creat performed worse than the CKD-EPI formula. Body composition did not significantly influence accuracy or precision of GFR estimation.

Conclusion

In HIV-infected patients in stable immunovirologic conditions with CKD stage 3 and high prevalence of metabolic associated conditions, the CKD-EPI formula performed best, although all formulae under estimate GFR.

[Correlation of blood concentration of tacrolimus with serum cystatin C in renal transplant recipients and effect of tacrolimus on glucose and lipid metabolism]

OBJECTIVE

To investigate the correlation between blood concentrations of tacrolimus (FK506) and cystatin C (Cys C) and the effect of FK506 on glycolipid metabolism in renal transplant recipients.

METHODS

A total of 325 patients receiving renal transplantation between August, 2014 and September, 2015 in Nanfang Hospital were divided into 4 groups according to the postoperative time (1 month group, 1-3 months group, 4-6 months group, and 7-12 months group). FK506 blood trough concentration was measured at the time of postoperative follow-up, and creatinine (Scr) and Cys C levels were also detected. Results Plasma FK506 concentration decreased with age in the recipients and showed a positive correlation with Cys C (r=0.985, P=0.015) but no obvious correlation with Scr (r=0.259, P=0.741). FK506 had no effect on blood glucose (5.53-5.59 mmol<L) or blood lipids (TG 1.47-1.55 mmol<L, TC 5.04-5.17 mmol<L, LDL-C 3.00-3.07 mmol<L, and VLDL 0.73-0.76 mmol<L) in patients 1-6 months after renal transplantation.

CONCLUSION

FK506 does not affect the level of glycolipid metabolism in patients after renal transplantation. Cys C is positively related to blood concentration of FK506 in the renal transplantation recipients. The rational use of FK506 can improve the effectiveness and safety of the treatment in the recipients.

Predictive value of cystatin C in people with suspected or established coronary artery disease: A meta-analysis

BACKGROUND AND AIMS

Circulating cystatin C has been recognized as an independent predictor of cardiovascular and all-cause mortality in the general population. We aimed to evaluate the prognostic value of baseline circulating cystatin C levels in people with suspected or established coronary artery disease (CAD) by conducting a meta-analysis.

METHODS

We searched Pubmed and Embase databases up to October 2016 for prospective observational studies investigating the predictive value of elevated circulating cystatin C levels in people with suspected or established CAD. Adverse vascular outcomes included all-cause mortality, cardiovascular mortality, or total adverse vascular events consisting of death, myocardial infarction, revascularization, stroke, and heart failure.

RESULTS

Ten studies involving participants with known or suspected CAD were included in this meta-analysis. When comparing the highest with the lowest cystatin C levels, the pooled hazard ratio (HR) was 2.27 (95% confidence interval [CI] 1.86-2.78) for all-cause mortality, 2.24 (95% CI 1.69-2.97) for cardiovascular mortality, and 1.87 (95% CI 1.57-2.24) for total adverse vascular events, respectively. Subgroup analysis results showed that this association was not influenced by follow-up duration, region, or CAD type.

CONCLUSIONS

Elevated circulating cystatin C is independently associated with adverse vascular outcomes in people with suspected or established CAD in terms of all-cause mortality, cardiovascular mortality, and total adverse vascular events. This increased risk is probably independent of creatinine/estimated glomerular filtration rate.

Osteoprotegerin as a marker of cardiovascular risk in children and adolescents with type 1 diabetes

BACKGROUND

Elevated osteoprotegerin (OPG) levels have been reported in patients with diabetes complications. We investigated whether plasma OPG levels can be used as a marker of cardiovascular risk in children and adolescents with type 1 diabetes (T1D).

METHODS

Plasma blood samples were obtained from 243 subjects (143 children and adolescents with T1D and 100 healthy controls). OPG concentrations were measured by enzyme-linked immunosorbent assay (ELISA) method. All data were analyzed by using PASW statistics 18.

RESULTS

A significant higher plasma OPG level was found in children with T1D compared to controls (p < 0.001). A significant increase of OPG levels has been related to the glucose level ≥ 7 mmol/L (2.44 [0.01-6.22] vs. 2.16 [0.13-6.22] pmol/L, p = 0.019), microalbuminuria ≥ 30 mg/24 h (3.71 [0.160-6.03] vs. 2.26 [0.01-6.22] pmol/L, p < 0.001), and cystatin-C ≥ 0.789 mg/L (2.64 [0.37-6.22] vs. 2.11 [0.01-5.82] pmol/L, p < 0.001). We noted a significant higher frequency of children with increased cystatin-C levels in the group with elevated plasma level of OPG compared with those with normal levels (49 vs. 18%, respectively) with an odds ratio (OR) = 4.42 [1.41-13.84] (p = 0.006). We showed a significant increase of OPG levels when the number of cardiovascular risk factors exceeds 3 (p = 0.001).

CONCLUSION

OPG may be a potential biomarker of cardiovascular risk in T1D. Implementation of OPG determination in the clinical laboratory setting would be useful in order to better stratify patients and to assess the most adequate treatment.

Multicenter Evaluation of Cystatin C Measurement after Assay Standardization

BACKGROUND

Since 2010, a certified reference material ERM-DA471/IFCC has been available for cystatin C (CysC). This study aimed to assess the sources of uncertainty in results for clinical samples measured using standardized assays.

METHODS

This evaluation was performed in 2015 and involved 7 clinical laboratories located in France and Belgium. CysC was measured in a panel of 4 serum pools using 8 automated assays and a candidate isotope dilution mass spectrometry reference measurement procedure. Sources of uncertainty (imprecision and bias) were evaluated to calculate the relative expanded combined uncertainty for each CysC assay. Uncertainty was judged against the performance specifications derived from the biological variation model.

RESULTS

Only Siemens reagents on the Siemens systems and, to a lesser extent, DiaSys reagents on the Cobas system, provided results that met the minimum performance criterion calculated according to the intraindividual and interindividual biological variations. Although the imprecision was acceptable for almost all assays, an increase in the bias with concentration was observed for Gentian reagents, and unacceptably high biases were observed for Abbott and Roche reagents on their own systems.

CONCLUSIONS

This comprehensive picture of the market situation since the release of ERM-DA471/IFCC shows that bias remains the major component of the combined uncertainty because of possible problems associated with the implementation of traceability. Although some manufacturers have clearly improved their calibration protocols relative to ERM-DA471, most of them failed to meet the criteria for acceptable CysC measurements.

Plasma biomarker levels and non-obstructive coronary artery disease determined by coronary computed tomography angiography

PURPOSE

Coronary computed tomography angiography (CTA) and several circulating biomarkers have prognostic value regarding cardiovascular disease (CVD) events, but their association is incompletely studied. We aimed to investigate whether markers of lipid metabolism, inflammation and kidney function could predict non-obstructive coronary artery disease (CAD) determined by coronary CTA, in a low-to-intermediate-risk group.

METHODS

Coronary CTA and laboratory testing were performed for 115 subjects (45-70 years), with low prevalence of CVD risk factors, predominantly low-to-intermediate Framingham risk and normal or mildly reduced kidney function.

RESULTS

Forty-nine (43%) had no CAD at coronary CTA, and 66 (57%) had CAD in ≥1 segment (stenosis < 50%). Adiponectin was inversely associated with CAD, and lipoprotein(a) and cystatin C were associated with CAD at coronary CTA. In multivariable logistic regression, cystatin C remained an independent predictor of CAD (OR: 2·50, 95% CI: 1·12-5·59). Cystatin C also correlated to the number of diseased segments (r_s  = 0·25, P<0·01).

CONCLUSION

Higher plasma levels of cystatin C were associated with non-obstructive CAD at coronary CTA in subjects with low-to-intermediate CVD risk and normal to mildly reduced kidney function.

Blood Selenium Concentration and Blood Cystatin C Concentration in a Randomly Selected Population of Healthy Children Environmentally Exposed to Lead and Cadmium

This study aimed at evaluation of a relationship between blood selenium concentration (Se-B) and blood cystatin C concentration (CST) in a randomly selected population of healthy children, environmentally exposed to lead and cadmium. The studies were conducted on 172 randomly selected children (7.98 ± 0.97 years). Among participants, the subgroups were distinguished, manifesting marginally low blood selenium concentration (Se-B 40-59 μg/l), suboptimal blood selenium concentration (Se-B: 60-79 μg/l) or optimal blood selenium concentration (Se-B ≥ 80 μg/l). At the subsequent stage, analogous subgroups of participants were selected separately in groups of children with BMI below median value (BMI <16.48 kg/m²) and in children with BMI ≥ median value (BMI ≥16.48 kg/m²). In all participants, values of Se-B and CST were estimated. In the entire group of examined children no significant differences in mean CST values were detected between groups distinguished on the base of normative Se-B values. Among children with BMI below 16.48 kg/m², children with marginally low Se-B manifested significantly higher mean CST values, as compared to children with optimum Se-B (0.95 ± 0.07 vs. 0.82 ± 0.15 mg/l, p < 0.05). In summary, in a randomly selected population of healthy children no relationships could be detected between blood selenium concentration and blood cystatin C concentration. On the other hand, in children with low body mass index, a negative non-linear relationship was present between blood selenium concentration and blood cystatin C concentration.

Cystatin C Levels in Middle-Aged Patients with Obstructive Sleep Apnea Syndrome

Background. Obstructive sleep apnea syndrome (OSAS) is associated with systemic inflammation and increased risk of cardiovascular and chronic kidney disease. Cystatin C (Cyst C) is a novel biomarker of both latent renal damage and cardiovascular disease. Aim of the study was to measure serum levels of Cyst C, as well as IL-8 and CRP, in otherwise healthy OSAS patients. Methods. 84 individuals examined with polysomnography for OSAS symptoms without known comorbidities were prospectively recruited. Results. According to apnea hypopnea index (AHI) subjects were divided in two groups: OSAS group (AHI > 5/hour, n = 64) and controls (AHI < 5/hour, n = 20), which were age- and BMI-matched. Cyst C levels were higher in OSAS patients versus controls (1176.13 ± 351.33 versus 938.60 ± 245.83 ng/mL, resp.; p = 0.017) while serum IL-8 and CRP levels did not differ significantly. Positive correlation was found between Cyst C levels and respiratory disturbance index (RDI) (r = 0.240, p = 0.039) and percentage of time with oxygen saturation <90% (r = 0.290, p = 0.02) and negative correlation was found between Cyst C levels and average oxygen saturation during sleep (r = -0.291, p = 0.012). After adjustment for age and BMI, RDI was the only independent predictor of Cyst C levels (β = 0.256, p = 0.039). Conclusion. Cyst C serum levels are increased in OSAS patients without comorbidities, suggesting an increased renal and cardiovascular disease risk.

Cystatin C, a novel cardiometabolic risk marker in women with polycystic ovary syndrome

OBJECTIVE

To investigate the impact of urinary albumin excretion (UAE) and cystatin C on the metabolic components of polycystic ovary syndrome (PCOS).

METHODS

Seventy-five women with PCOS were divided into two groups according to metabolic syndrome as MetS + and MetS-. Clinical, metabolic and renal parameters were compared between the groups. Correlation analyses were performed between cystatin C, microalbuminuria and clinical and metabolic parameters in women with PCOS.

RESULTS

Waist/hip ratio (WHR), body mass index, LDL cholesterol, triglyceride, total cholesterol, cystatin C, UAE were significantly higher in the MetS + group compared with the MetS - one. HDL cholesterol was significantly higher in the MetS - group than the MetS + one. The UAE positively correlates with LDL cholesterol, triglyceride and total cholesterol levels. Cystatin C positively correlates with UAE, WHR, LDL cholesterol, triglyceride, total cholesterol levels.

CONCLUSIONS

Evaluating UAE and cystatin C may be important for the detection of target subjects at high risk for future metabolic syndrome and cardiovascular disease.