Low-Density Lipoprotein Cholesterol and Mortality in Peritoneal Dialysis

Background

In dialysis patients, lowering low-density lipoprotein cholesterol (LDL-C) did not provide benefits, which seemed implausible in clinical practice. We hypothesized a U-shaped association between LDL-C and mortality in dialysis patients.

Methods

In this multi-center retrospective real-world cohort study, 3,565 incident Chinese peritoneal dialysis (PD) patients between January 1, 2005, and May 31, 2020, were included. The associations between baseline LDL-C and mortality were examined using cause-specific hazard models.

Results

Of 3,565 patients, 820 died, including 415 cardiovascular deaths. As compared with the reference range (2.26-2.60 mmol/L), both higher levels of LDL-C (> 2.60 mmol/L) and lower levels of LDL-C (< 2.26 mmol/L) were associated with increased risks of all-cause mortality (hazard ratio [HR],1.35, 95% confidence index [CI], 1.09-1.66; HR 1.36, 95%CI, 1.13-1.64) and cardiovascular mortality (HR, 1.31, 95% CI, 1.10-1.72; HR, 1.64; 95% CI, 1.22-2.19). Malnutrition (albumin < 36.0 g/L) modified the association between LDL-C and cardiovascular mortality (P for interaction = 0.01). A significantly increased risk of cardiovascular mortality was observed among patients with malnutrition and lower levels of LDL-C (HR 2.96, 95%CI 1.43-6.12) or higher levels of LDL-C (HR 2.81, 95%CI 1.38-5.72).

Conclusion

Low and high levels of LDL-C at the start of PD procedure were associated with increased all-cause and cardiovascular mortality risks. Malnutrition may modify the association of LDL-C with cardiovascular mortality.

The predictive study of the relation between elevated low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and mortality in peritoneal dialysis

BACKGROUND

The low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio constitutes a strong risk predictor of cardiovascular events. However, the association between this ratio and cardiovascular death in peritoneal dialysis (PD) patients is uncertain. The study aimed to investigate whether a high LDL-C/HDL-C ratio could predict both cardiovascular and all-cause mortalities in patients on PD.

METHODS

A total of 1616 incident patients on PD included from January 1, 2006 to December 31, 2013 were followed up with until 31 December 2018 in this single-center prospective cohort study. Participants were divided into three categories according to LDL-C/HDL-C ratio tertile. The primary endpoint was cardiovascular mortality; the secondary endpoint was all-cause mortality.

RESULTS

The mean age of the study cohort was 47.5 years and the mean body mass index (BMI) was 21.6 kg/m2. During a median follow-up period of 47.6 months, 492 patients died, including 246 (50.0%) due to cardiovascular disease (CVD). A multivariate analysis revealed that the highest LDL-C/HDL-C ratio tertile was significantly associated with increased CVD mortality [hazard ratio (HR): 1.69, 95% CI: 1.24-2.29; P = 0.001] and all-cause mortality (HR: 1.46, 95% CI: 1.18-1.81; P = 0.001) relative to the lowest tertile. After adjusting for covariates, the HRs of cardiovascular and all-cause mortalities were 1.84 (95% CI: 1.25-2.71; P = 0.002) and 1.35 (95% CI: 1.03-1.77; P = 0.032). Subgroup analysis showed that the risk of CVD death rose with a higher LDL-C/HDL-C ratio among PD patients who were female, younger than 65 years old, without being malnourished (BMI ≥ 18.5 kg/m2 or albumin ≥35 g/L), and with a history of diabetes or CVD, respectively.

CONCLUSIONS

A high LDL-C/HDL-C ratio is an independent risk factor for both cardiovascular and all-cause mortalities among PD patients.

Association of Adiponectin with High-Sensitivity C-Reactive Protein and Clinical Outcomes in Peritoneal Dialysis Patients: A 3.5-Year Follow-Up Study

Introduction

Adiponectin (ADPN), one of most abundant fat-derived biologically active substances, plays an important role in anti-atherosclerotic process. There are conflicting results about the impact of ADPN on cardiovascular (CV) outcomes and mortality, particularly in patients undergoing peritoneal dialysis (PD). Moreover, the relationship between ADPN and inflammatory mediators has been seldom explored in this population. Therefore, we examined the relationship between ADPN and longitudinal high-sensitivity C-reactive protein (hs-CRP) changes and investigated whether ADPN or hs-CRP levels could predict CV outcomes and mortality in prevalent PD patients after comprehensive adjustment of possible confounders.

Methods

In this prospective cohort study, 78 PD patients were enrolled and followed from February 2009 to August 2012. During follow-up, CV events and all-cause mortality were recorded.

Results

The mean baseline ADPN value was 29.46±18.01 μg/ml and duration of PD treatment was 37.76±36.96 months. In multiple linear regression analysis, plasma ADPN levels positively correlated with high-density lipoprotein and negatively associated with hs-CRP, body mass index, D4/D0 glucose, triglyceride, and duration of PD treatment. After stratified by genders, the inverse association between baseline ADPN and hs-CRP was more significant in the female group. The hs-CRP levels were followed up annually and remained significantly lower in the high ADPN group in the first 2 years. Patients were then stratified into two groups according to the median ADPN value (23.8 μg/ml). The results of Kaplan-Meier survival analysis demonstrated less CV events and better survival in high ADPN group. On multivariate Cox regression analysis, only ADPN level (HR: 0.93, 95% CI: 0.88–0.98, p = 0.02), age and history of CV diseases were independent risk factors for future CV events. Furthermore, hs-CRP (HR: 1.11, 95% CI:1.001–1.22, p = 0.04) was identified as independent predictor of all-cause mortality.

Conclusions

Serum hs-CRP levels were consistently lower in the high ADPN group during 2-year follow-up. We also demonstrated the importance of ADPN and hs-CRP in predicting CV events and all-cause mortality in PD population during 3.5-year follow-up.

Carotid atherosclerosis is associated with enhanced β-chemokine levels in patients on continuous ambulatory peritoneal dialysis

Increased oxidative stress (SOX) has been reported in continuous ambulatory peritoneal dialysis (CAPD) patients, but its influence on beta-chemokine levels and progression of atherosclerosis remains unknown. We determined three distinct SOX markers: Cu/Zn superoxide dismutase (Cu/Zn SOD), total peroxide and autoantibodies against oxidized LDL (OxLDL-Ab); high sensitivity C-reactive protein (hs CRP); beta-chemokines: monocyte chemoattractant protein-1 (CCL2), macrophage inflammatory proteins (CCL3 and CCL4) and regulated upon activation, normal T cell expressed and secreted (CCL5) and the intima-media thickness (IMT) values in CAPD patients both with and without cardiovascular disease (CVD) and healthy controls. CAPD patients both with and without CVD had significantly increased IMT (p<0.001 and <0.01), Cu/Zn SOD (both p<0.001) and CCL2 levels (p<0.001 and <0.01, respectively) as compared to controls. CCL4 (p<0.01) and hs CRP (p<0.05) were increased only in patients with CVD, whereas there were no differences in the total peroxide, OxLDL-Ab and CCL3 levels between patients and controls. CCL5 concentrations were significantly decreased in both patients subgroup (both p<0.001) versus controls. Multivariate analysis showed that age (p<0.001), male sex (p<0.01), CCL4 and CCL2 levels (both p<0.05) were the independent variables linked to IMT values. Our data suggest a possible role of enhanced beta-chemokine levels in the carotid atherosclerosis in patients treated with CAPD, in addition to age and male sex.