The relation between apelin levels, echocardiographic findings and carotid intima media thickness in peritoneal dialysis patients

Elabela Attenuates the TGF-β1-Induced Epithelial-Mesenchymal Transition of Peritoneal Mesothelial Cells in Patients Receiving Peritoneal Dialysis

Peritoneal fibrosis (PF), a common complication in patients receiving peritoneal dialysis (PD), is primarily caused by the epithelial-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs). PF is the main reason for patients on PD to withdraw from PD. Effective treatment is unavailable for this complication at present. Elabela (ELA) is a polypeptide hormone secreted by the vascular endothelium and kidney. Peptide hormones ELA and apelin (APLN) have various protective effects on the cardiovascular and urinary systems and have potential therapeutic effects on organ fibrosis. ELA and APLN are less studied in PD population. Here, we aimed to investigate the clinical significance of ELA in patients on PD and to evaluate the therapeutic effect of ELA on EMT of HPMCs. Compared with those in patients with stage 5 chronic kidney disease who are not on dialysis, serum ELA levels in patients on PD increased with the improvement of residual renal function at PD duration <36 months and decreased to pre-dialysis levels at PD duration ≥36 months, suggesting that dialysis duration is the main risk factor affecting serum ELA levels in patients on PD. In addition, serum APLN levels decreased in the early stage of PD and recovered to the pre-dialysis level with the prolongation of dialysis time. Notably, serum APLN levels were positively correlated with dialysis duration in patients undergoing PD. To establish the EMT model, we stimulated HPMCs using transforming growth factor-beta 1 (TGF-β1) in cell experiments performed in vitro. ELA-32 treatment reversed the TGF-β1-induced reduction in the expression of the epithelial cell marker and suppressed the expression of mesenchymal cell markers by inhibiting the phosphorylation of SMAD2/3, ERK1/2, and AKT. Therefore, our findings imply that ELA-32 can interfere with the EMT of HPMCs by inhibiting the activation of the TGF-β/SMAD2/3, ERK1/2, and AKT pathways, providing novel insights on the potential therapeutic use of ELA for treating PD-related PF.

The relationship between apelin and carotid intima media thickness, and the presence of plaque in dialysis patients

BACKGROUND

Apelin is a peptide that has important effects on the cardiovascular system due to its anti-atherogenic properties and regulating blood pressure. There is not enough research evaluating the effects of apelin levels on the cardiovascular system in hemodialysis (HD) and peritoneal dialysis (PD) patients concurrently. The aim of this study was to determine apelin levels in dialysis, and control groups and to investigate the relationship between apelin and carotid intima media thickness (CIMT).

MATERIALS AND METHODS

Thirty three HD patients, 35 PD patients, and 15 healthy individuals were included in the study. All laboratory data, N-terminal pro-B-type natriuretic peptide (NT-proBNP), IL-6, and apelin-13 levels were analyzed. To prevent interobserver errors in CIMT measurement, the analyses were performed by a single radiologist.

RESULT

CIMT, presence of plaque, apelin, NT-proBNP, IL-6, and C-reactive protein (CRP) levels were higher in dialysis patients. There was a relationship between apelin and CIMT, and between apelin and high-density lipoprotein (HDL) in PD patients. Age, apelin, HDL, parathormone (PTH), glucose, and smoking were found to affect the presence of plaque in dialysis patients.

CONCLUSION

Apelin levels were high in dialysis patients. Especially in PD patients, there was a negative correlation between apelin and CIMT, and between apelin and HDL. Therefore, apelin may play a role in the pathogenesis of cardiovascular diseases in PD patients.

Correlation of serum apelin level with carotid intima–media thickness and insulin resistance in a sample of Egyptian patients with type 2 diabetes mellitus

Background:

Type 2 diabetes mellitus (T2DM) is a growing health problem in Egypt, with a significant impact on morbidity and mortality. Measurement of the carotid Intima-media thickness (CIMT) allows early detection of atherosclerotic blood vessel diseases. Apelin is an adipose tissue-derived hormone that may be associated with insulin resistance (IR). This study aimed to assess the level of serum apelin in patients with T2DM and its relation to IR and CIMT.

Materials and Methods:

A case-control study was conducted on 60 patients with T2DM and 30 healthy controls. T2DM was diagnosed based on American Diabetes Association criteria. The study was carried out at Al-Zahraa University Hospital, Cairo, Egypt, through the period from June to December 2019. The laboratory investigations included serum apelin and blood glucose hemostasis markers. CIMT was assessed using B-mode ultrasonography.

Results:

Patients’ group had a statistically significant higher apelin level than healthy controls (407.96 ± 291.07 versus 83.32 ± 10.55 ng/dL, P < 0.001). The correlation analysis showed that the serum apelin level correlated positively with glycemic indices, body weight, and waist circumference (P < 0.05). At cutoff value of >96 ng/dL, the serum apelin exhibited a sensitivity of 98.3% and specificity of 96.7%, positive predictive value of 98.1%, and negative predictive value of 96.5%, with a diagnostic accuracy of 95.1%. Serum apelin correlated positively with CIMT (r = 0.296, P = 0.022). Logistic regression analysis showed that systolic and diastolic blood pressures, Homeostasis Model Assessment of IR, and CIMT were independent predictors of serum apelin.

Conclusion:

Serum apelin may be correlated with the degree of carotid atherosclerosis and hence can be used as a prognostic biomarker.

Baseline carotid intima-media thickness is associated with cardiovascular morbidity and mortality in peritoneal dialysis patients

Carotid intima-media thickness (CIMT) is an early marker of atherosclerosis and is increased in peritoneal dialysis (PD) patients. Association of CIMT with cardiovascular disease (CVD) or mortality is less clear. Fibroblast growth factor-23 (FGF-23) is a hormone associated with vascular calcification, atherosclerosis, and mortality in the hemodialysis population. We investigated whether baseline CIMT and FGF-23 are associated with CVD and mortality in PD patients. Fifty-five PD patients were included. CVD was defined as ischemic heart disease, stroke, or peripheral artery disease. Intact FGF-23 was measured in plasma. CIMT was measured by ultrasonography. Twenty-one patients developed CVD and 12 died over 47.1 ± 33.8 months. Patients with CVD were older (55.9 ± 10.5 vs. 42.5 ± 12.9 years, P < .01), had lower albumin (3.8 ± 0.5 vs. 4.2 ± 0.3 g/dL, P < .01) and higher CIMT (0.87 ± 0.22 vs. 0.61 ± 0.11 mm, P < .01). Patients with mortality were also older (53.5 ± 11.5 vs. 45.8 ± 13.8 years, P = .05), had lower albumin (3.7 ± 0.6 vs. 4.1 ± 0.3 g/dL, P < .01), higher CRP (15.0 ± 8.5 vs. 7.6 ± 8.4 mg/L, P < .01) and CIMT (0.9 ± 0.3 vs. 0.6 ± 0.1 mm, P < .01). Albumin and CIMT were associated with CVD and CIMT >  0.75 mm was associated with cardiovascular mortality. FGF-23 did not show any correlations. CIMT at baseline is associated with CVD and mortality in PD patients.