Carotid Intima-Media Thickness: A Surrogate Marker for Cardiovascular Disease in Chronic Kidney Disease Patients

The Role of Dyslipidemia in Atherogenesis in Peritoneal Dialysis Patients

Background

To evaluate atherosclerotic changes in carotid arteries (CCA) in uremic patients before and after 18 months of continuous ambulatory peritoneal dialysis (CAPD) treatment, and to evaluate the impact of dyslipidemia and CAPD treatment on vascular remodeling.

Materials and Methods

We conducted a longitudinal, prospective study during 2020 and 2021 at the Clinic for Nephrology, Clinical Center University of Sarajevo. Patients with end-stage renal disease were included and were followed during 18 months of CAPD treatment. All patients were treated using commercially prepared biocompatible balanced dialysis solutions. Carotid intima-media thickness (IMT) and atherosclerotic plaques on the common carotid artery (CCA) were measured by echotomography.

Results

A total of 50 patients were included and were followed during 18 months of CAPD treatment. Lipid values in the serum of patients with CAPD were significantly lower after 18 months of CAPD treatment compared to the values before treatment, while the value of high-density lipoprotein (HDL) was significantly increased after 18 months of CAPD treatment. The values of IMT and the diameter of the CCA compared to the basal values were significantly lower (P < 0.001).

Conclusion

We demonstrated significantly lower lipid values and higher HDL levels following CAPD treatment. Correct selection of the targeted pharmacological intervention can substantially impact the regression of vascular changes in patients on peritoneal dialysis.

Vascular calcification progression in patients with end-stage chronic kidney disease

BACKGROUND

Intima media thickness (IMT), vascular calcifications and ankle-brachial pressure index (ABPI) were shown to be independent predictors of mortality in end-stage renal disease (ESRD) patients.

METHODS

Between January 2018 and March 2019, a physician-initiated, nonrandomized, prospective study was conducted. Carotid IMT, vascular calcifications analysis values and measurements of the ABPI, were made at baseline and after 1-year of follow-up.

RESULTS

A total of 284 patients, 152 patients with dialysis (100 hemodialysis (HD) and 52 CAPD (continuous ambulatory peritoneal dialysis)) and 132 patients with stage 4 chronic kidney disease (control group), were included (55% male, 67 [29-88] years). The values of carotid IMT at baseline were higher in the HD group than in the CAPD group (1.10±0.08 mm vs. 0.08±0.04 mm, P=0.004). Adragao and Kauppila scores were higher in the HD group than in the CAPD group (2.56±2.10 vs. 1.08±2.02, P=0.009; and 7.40±6.86 vs. 4.44±5.26, P<0.001; respectively). These differences remained after 1-year of follow-up. Pathological ABPI after 1-year follow-up was more prevalent in the HD group than in the CAPD or control groups (32.0% vs. 19.4% vs. 7.7%, respectively, P=0.042). Multivariate regression analysis revealed that age, gender, dialysis type and LDLc were independent predictors for carotid IMT increase; age, dialysis type and smoking for vascular calcifications increase on Adragao Score; and dialysis type on Kauppila Score. Only the dialysis type was the independent predictor for all vascular calcifications markers.

CONCLUSIONS

Dialysis, particularly HD, is an independent risk factor for cardiovascular calcification increase in ESRD patients.

Diabetic patients with chronic kidney disease: Non-invasive assessment of cardiovascular risk

The prevalence and burden of diabetes mellitus and chronic kidney disease on global health and socioeconomic development is already heavy and still rising. Diabetes mellitus by itself is linked to adverse cardiovascular events, and the presence of concomitant chronic kidney disease further amplifies cardiovascular risk. The culmination of traditional (male gender, smoking, advanced age, obesity, arterial hypertension and dyslipidemia) and non-traditional risk factors (anemia, inflammation, proteinuria, volume overload, mineral metabolism abnormalities, oxidative stress, etc.) contributes to advanced atherosclerosis and increased cardiovascular risk. To decrease the morbidity and mortality of these patients due to cardiovascular causes, timely and efficient cardiovascular risk assessment is of huge importance. Cardiovascular risk assessment can be based on laboratory parameters, imaging techniques, arterial stiffness parameters, ankle-brachial index and 24 h blood pressure measurements. Newer methods include epigenetic markers, soluble adhesion molecules, cytokines and markers of oxidative stress. In this review, the authors present several non-invasive methods of cardiovascular risk assessment in patients with diabetes mellitus and chronic kidney disease.

Predialysis and Dialysis Therapies Differently Affect Nitric Oxide Synthetic Pathway in Red Blood Cells from Uremic Patients: Focus on Peritoneal Dialysis

Red blood cells (RBCs) have been found to synthesize and release both nitric oxide (NO) and cyclic guanosine monophosphate (cGMP), contributing to systemic NO bioavailability. These RBC functions resulted impaired in chronic kidney disease (CKD). This study aimed to evaluate whether predialysis (conservative therapy, CT) and dialysis (peritoneal dialysis, PD; hemodialysis, HD) therapies used during CKD progression may differently affect NO-synthetic pathway in RBCs. Our data demonstrated that compared to PD, although endothelial-NO-synthase activation was similarly increased, HD and CT were associated to cGMP RBCs accumulation, caused by reduced activity of cGMP membrane transporter (MRP4). In parallel, plasma cGMP levels were increased by both CT and HD and they significantly decreased after hemodialysis, suggesting that this might be caused by reduced cGMP renal clearance. As conceivable, compared to healthy subjects, plasma nitrite levels were significantly reduced by HD and CT but not in patients on PD. Additionally, the increased carotid intima-media thickness (IMT) values did not reach the significance exclusively in patients on PD. Therefore, our results show that PD might better preserve the synthetic NO-pathway in CKD-erythrocytes. Whether this translates into a reduced development of uremic vascular complications requires further investigation.