The association between platelet indices and cardiovascular events in chronic kidney disease patients without dialysis

The relationship of platelet distribution width with all-cause and cardiovascular mortality in peritoneal dialysis patients

BACKGROUND

Cardiovascular disease (CVD) is a major complication in peritoneal dialysis (PD) patients. Previous studies have demonstrated that platelet distribution width (PDW) is associated with cardiovascular events in hemodialysis (HD) patients. In this study, we hypothesized that elevated PDW can predict all-cause and cardiovascular mortality in PD patients.

METHODS

We recruited PD patients for a single-center retrospective cohort study from 1 January 2007, to 30 June 2020. Receiver-operating characteristic (ROC) curves were made to determine the PDW cutoff value for predicting all-cause mortality. The propensity score matching (PSM) method was used to improve the equilibrium between groups. The relation of PDW with all-cause and cardiovascular mortality was analyzed by Cox proportional hazards models. Restricted cubic spline (RCS) models were used to determine whether there was a linear relationship between PDW and all-cause and cardiovascular mortality.

RESULTS

A total of 720 PD patients were screened, and 426 PD patients were enrolled after PSM. After adjusting for confounders, Cox proportional hazards models showed that the PDW value was positively correlated with the risk of all-cause and cardiovascular mortality (HR = 1.162, 95% CI 1.057-1.278, p = 0.002 and HR = 1.200, 95% CI 1.041-1.382, p = 0.012). The adjusted RCS analysis further showed that the relationship of PDW with all-cause and cardiovascular mortality was linear (p for nonlinearly = 0.143 and 0.062).

CONCLUSION

Elevated PDW is independently associated with all-cause and cardiovascular mortality in PD patients.

The impact of depression on platelet activation, cardiocerebral vascular events and arteriovenous fistula dysfunction in patients undergoing haemodialysis

Depression is a common psychiatric disorder among patients undergoing maintenance haemodialysis (MHD). Depression may reportedly contribute to poor prognosis in several ways, including its effects on platelet function. We hypothesised that depression contributes to the occurrence of cardiocerebral vascular events (CCVE) and dysfunction of arteriovenous fistula (DAVF) in patients undergoing MHD through its effects on platelets. In this prospective cohort study, patients undergoing MHD were recruited and divided into depression and non-depression groups according to their Hamilton Depression Scale (HAMD) scores. The 286 enrolled patients had 103 occurrences of depressive symptoms (prevalence = 36.01%). Compared with the non-depression group, depression group had a significantly higher cumulative prevalence of CCVE and DAVF during follow-up. Cox regression analysis indicated that higher HAMD scores and lower plasma platelet distribution width (PDW) were common risk factors for CCVE and DAVF. Furthermore, HAMD scores were significantly negatively correlated with plasma PDW and was the main variable affecting changes in PDW, as indicated by multiple linear regression analysis. Depression may increase the risk of CCVE and DAVF in patients undergoing MHD by activating platelets. Plasma PDW may be a convenient indicator of platelet activation status and may predict the risk of CCVE and DAVF.

Systemic immune inflammation index and all-cause mortality in chronic kidney disease: A prospective cohort study

BACKGROUND

The aim of this study was to investigate the association between systemic immune-inflammation index (SII) and all-cause mortality in individuals with chronic kidney disease (CKD).

PATIENTS AND METHODS

This prospective cohort study was carried out among 9303 participants with CKD from the National Health and Nutrition Examination Survey cycles spanning 1999 to 2018. The mortality data were ascertained by linking participant records to the National Death Index up to December 31, 2019. Complex sampling-weighted multivariate Cox proportional hazards models were employed to estimate the association between SII level and all-cause mortality, providing hazard ratios (HR) and 95% confidence intervals (CI). A restricted cubic spline analysis was conducted to explore potential nonlinear correlation. Subgroup analyses and sensitivity analyses were also conducted.

RESULTS

During a median follow-up period of 86 months, 3400 (36.54%) all-cause deaths were documented. A distinctive "J"-shaped relationship between SII level and all-cause mortality was discerned among individuals with CKD, with the nadir observed at an SII level of 478.93 within the second quartile. After adjusting for potential covariates, the risk of all-cause mortality escalated by 13% per increment of one standard deviation of SII, once SII exceeded 478.93 (HR = 1.13; 95% CI = 1.08-1.18). An elevated SII was associated with an increased risk of all-cause mortality among patients with CKD (Q4 vs. Q2: HR = 1.23; 95% CI = 1.01-1.48). Subgroup analyses indicated that the correlation between SII and CKD mortality was particularly pronounced among participants over 60 years old and individuals with diabetes. Sensitivity analyses revealed a linear positive association between SII and all-cause mortality after removing the extreme 5% outliers of SII.

CONCLUSIONS

A distinctive "J"-shaped relationship between SII level and all-cause mortality was identified among individuals with CKD. Further research is warranted to validate and expand upon these findings.

Serum platelet distribution width predicts cardiovascular and all-cause mortality in patients undergoing peritoneal dialysis

BACKGROUND

Platelet distribution width (PDW) is a predictor for all-cause mortality in patients with cardiovascular diseases (CVD). This study aimed to evaluate the prognostic implication of PDW in predicting cardiovascular and all-cause mortality in patients undergoing peritoneal dialysis (PD).

METHODS

In total, 762 PD patients from a single center were recruited retrospectively from 2005 to 2017 and followed up until 2021. The primary and secondary outcomes were cardiovascular and all-cause mortality, respectively. Survival analysis was conducted using Kaplan-Meier estimates and Cox regression analysis.

RESULTS

During a median of 52.2 months of follow-up, 135 (17.7%) cases of CVD and 253 (33.2%) cases of all-cause mortality were reported. After multivariate adjustment, high levels of PDW were associated with an increased risk of death from CVD (HR: 1.583; 95% CI: 1.109-2.258; P = 0.011) and all-cause mortality (HR: 1.313; 95% CI: 1.006-1.758; P = 0.045). Subgroup analysis indicated a stronger association between PDW and all-cause mortality among female participants (P-value for interaction = 0.033). Higher levels of PDW predicted an increased risk of all-cause mortality in female patients (HR: 1.986; 95% CI,1.261-3.127).

CONCLUSION

High levels of PDW are independently associated with cardiovascular and all-cause mortality in the PD population, and differences by sex exist in the association of PDW with all-cause mortality.

The relationship between platelet distribution width and new-onset cardiovascular disease events in patients with peritoneal dialysis

Objectives

The global mortality rate from chronic kidney disease (CKD) has increased over the past two decades. Typically, peritoneal dialysis (PD) remains a useful alternative treatment for end-stage renal disease. Cardiovascular disease (CVD) is the main complication in PD patients. In terms of prognosis, it is reported that platelet distribution width (PDW) can predict adverse CVD events. However, the relationship between PDW and new-onset CVD in PD patients is not clear. This study aimed to explore the relationship between PDW and new-onset CVD in PD patients.

Methods

This was a retrospective cohort study, from 4 July 2005 to 31 December 2019, and a total of 1557 patients were recruited. PDW was respectively categorized into two groups: PDW ≤13.2 fL and PDW >13.2 fL. The primary outcome was a new-onset CVD event. Cox proportional hazards models were performed to assess the hazard ratio (HR). Receiver-operating characteristic (ROC) curves were applied to evaluate the predictive accuracy of the PDW on CVD events.

Results

During follow-up, 114 new-onset CVD events were recorded. Cox proportional hazards models showed a higher risk of CVD events in patients with high PDW (HR = 1.862 95%CI 1.205–2.877, p = 0.005). Kaplan–Meier cumulative incidence curves showed the risk of the first occurrence of CVD events was greater in the high PDW group (p = 0.006).

Conclusions

High PDW is associated with new-onset cardiovascular disease events in PD patients.

Renal Klotho safeguards platelet lifespan in advanced chronic kidney disease through restraining Bcl-xL ubiquitination and degradation

BACKGROUND

Thrombosis and hemorrhage as two opposite pathologies are prevalent within the chronic kidney disease (CKD) population. Platelet homeostasis, which positions centrally in their pathogenesis, varies among the CKD population, while the underlying mechanism is poorly understood.

OBJECTIVE

To investigate the change character and mechanism of platelet homeostasis in CKD and its association with renal Klotho deficiency.

METHODS

The change character of platelet homeostasis and its association with renal Klotho deficiency were determined based on a cohort study as well as CKD mice and Klotho-deficient mice with CKD. The effects on thrombopoiesis and platelet lifespan were examined by flow cytometry and platelet transfer. The underlying mechanism was explored by proteomics, flow cytometry, western blot, and immunoprecipitation.

RESULTS

We show that platelet count declines both in patient and mouse models with advanced CKD (Adv-CKD) and is positively associated with circulating Klotho levels. Mechanistically, we identify that ubiquitin ligase UBE2O governs Bcl-xL ubiquitination and degradation in platelets, whereas Adv-CKD-induced oxidative stress in platelets stimulates p38MAPK to promote Bcl-xL phosphorylation, which facilitates UBE2O binding to Bcl-xL and subsequent Bcl-xL degradation. Consequently, platelet lifespan is shortened in Adv-CKD, culminating in platelet count decline. However, kidney-secreted soluble Klotho protein restricts oxidative stress in platelets, thereby preserving Bcl-xL expression and platelet lifespan.

CONCLUSIONS

Our findings uncover the mechanism of platelet count decline in Adv-CKD and identify renal Klotho as a long-range regulator of platelet lifespan, which not only provide a molecular mechanism underlying CKD-associated thrombocytopenia and hemorrhage but also offer a promising therapy choice.

Platelet-Dependent Inflammatory Dysregulation in Patients with Stages 4 or 5 Chronic Kidney Disease: A Mechanistic Clinical Study

Background

Chronic kidney disease (CKD) is characterized by dysregulated inflammation that worsens with CKD severity. The role of platelets in modulating inflammation in stage 4 or 5 CKD remains unexplored. We investigated whether there are changes in platelet-derived thromboinflammatory markers in CKD with dual antiplatelet therapy (DAPT; aspirin 81 mg/d plus P2Y12 inhibitor).

Methods

In a mechanistic clinical trial, we compared platelet activation markers (aggregation and surface receptor expression), circulating platelet-leukocyte aggregates, leukocyte composition (monocyte subtypes and CD11b surface expression), and plasma cytokine profile (45 analytes) of non-CKD controls (n=26) and CKD outpatients (n=48) with a glomerular filtration rate (GFR) <30 ml/min per 1.73 m² on 2 weeks of DAPT.

Results

Patients with CKD demonstrated a reduced mean platelet count, elevated mean platelet volume, reduced platelet-leukocyte aggregates, reduced platelet-bound monocytes, higher total non-classic monocytes in the circulation, and higher levels of IL-1RA, VEGF, and fractalkine (all P<0.05). There were no differences in platelet activation markers between CKD and controls. Although DAPT reduced platelet aggregation in both groups, it had multifaceted effects on thromboinflammatory markers in CKD, including a reduction in PDGF levels in all CKD individuals, reductions in IL-1β and TNF-α levels in select CKD individuals, and no change in a number of other cytokines. Significant positive correlations existed for baseline IL-1β, PDGF, and TNF-α levels with older age, and for baseline TNF-α levels with presence of diabetes mellitus and worse albuminuria. Mean change in IL-1β and PDGF levels on DAPT positively correlated with younger age, mean change in TNF-α levels with higher GFR, and mean changes in PDGF, and TRAIL levels correlated with worse albuminuria. Minimum spanning trees plot of cytokines showed platelet-derived CD40L had a large reduction in weight factor after DAPT in CKD. Additionally, platelet-derived IL-1β and PDGF were tightly correlated with other cytokines, with IL-1β as the hub cytokine.

Conclusions

Attenuated interactions between platelets and leukocytes in the CKD state coincided with no change in platelet activation status, an altered differentiation state of monocytes, and heightened inflammatory markers. Platelet-derived cytokines were one of the central cytokines in patients with CKD that were tightly correlated with others. DAPT had multifaceted effects on thromboinflammation, suggesting that there is platelet-dependent and -independent inflammation in stage 4 or 5 CKD.