An improvement of carotid intima-media thickness and pulse wave velocity in renal transplant recipients

Quantifying carotid stiffness in chronic kidney disease using ultrafast ultrasound imaging

Background

The mortality and disability of chronic kidney disease (CKD) are highly linked to the incidence of atherosclerotic cardiovascular events. Numerous clinical biochemical indicators of renal function often only increase in advanced stages of CKD, driving an urgent need for reliable indicators of atherosclerosis in early CKD. Ultrafast pulse wave velocity (ufPWV) can evaluate the stiffness of the straight carotid in vivo and quantitatively reflect the degree of early atherosclerosis. However, the use of ufPWV in CKD has not yet been reported. In this study, we aimed to explore the association between carotid stiffness, quantified using ufPWV, and renal function in CKD patients.

Methods

This cross-sectional study enrolled a total of 582 participants between March 2017 and May 2022 in the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine. Among those, 205 individuals without a history of CKD and estimated glomerular filtration rate (eGFR) ≥90 mL/min/1.73 m2 were included as controls. According to the Kidney Disease Outcomes Quality Initiative (K/DOQI) expert group of the American Kidney Foundation staging for CKD, 44 stages 1 and 2 CKD patients were included in the early CKD group, whereas 49 stages 3, 4, and 5 CKD patients were included in the advanced CKD group. Clinical and serum parameters, ultrasonic characteristics including carotid intima-media thickness (cIMT), and pulse wave velocity at the beginning of systole (PWV-BS) and pulse wave velocity at the end of systole (PWV-ES) of systole were analyzed. One-way analysis of variance (ANOVA) and least significant difference (LSD) tests were performed to compare cIMT, PWV-BS, and PWV-ES among subgroups in pairs. Pearson's correlation analysis, scatter plots, and subgroups correlation analysis were used to determine the relationships among ultrasound characteristics (cIMT, PWV-BS, PWV-ES), and major cardiovascular risk factors.

Results

PWV-BS and PWV-ES for the early and advanced CKD groups were significantly higher than those for controls (all P<0.05). PWV-ES had the greatest correlation with age (r=0.474, P<0.001). PWV-ES had the greatest increase with age in the early CKD group (r=0.698, P<0.001).

Conclusions

ufPWV can be used for the quantitative evaluation of carotid stiffness in CKD patients. PWV-ES may be more advantageous in the assessment of carotid atherosclerosis in early CKD patients.

Investigation of the Relationship between Cardiovascular Biomarkers and Brachial-Ankle Pulse Wave Velocity in Hemodialysis Patients

Brachial−ankle pulse wave velocity (baPWV) and cardiovascular (CV) biomarkers are correlated with clinical cardiovascular diseases (CVDs) in patients with kidney disease. However, limited studies evaluated the relationship between baPWV and CV biomarkers in hemodialysis patients. This study investigated the relationship between circulating CV biomarkers and baPWV in patients on hemodialysis. Hemodialysis patients were enrolled between August 2016 and January 2017 for the measurement of baPWV, traditional CV biomarkers, including high-sensitivity troponin-T (hsTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), and novel CV biomarkers, including Galectin-3, Cathepsin D, placental growth factor, Endocan-1, and Fetuin-A. The independent association was assessed by multivariate-adjusted linear regression analysis to control for potential confounders. The final analysis included 176 patients (95 men and 81 women) with a mean age of 60 ± 11 y old. After adjusting for age and sex, hsTnT (p < 0.01), NT-proBNP (p = 0.01), Galectin-3 (p = 0.03), and Cathepsin D (p < 0.01) were significantly directly correlated with baPWV. The direct correlation with baPWV existed in multivariable linear regression models with a β of 0.1 for hsTnT and 0.1 for Cathepsin D. The direct relationship between baPWV and CV biomarkers, particularly with hsTnT and Cathepsin D, may be helpful for risk stratification of hemodialysis patients.

Influence of Belatacept- vs. CNI-Based Immunosuppression on Vascular Stiffness and Body Composition

Background: Arterial stiffness and phase angle (PhA) have gained importance as a diagnostic and prognostic parameter in the management of cardiovascular disease. There are few studies regarding the differences in arterial stiffness and body composition between renal transplant recipients (RTRs) receiving belatacept (BELA) vs. calcineurin inhibitors (CNI). Therefore, we investigated the differences in arterial stiffness and body composition between RTRs treated with different immunosuppressants, including BELA. Methods: In total, 325 RTRs were enrolled in the study (mean age 52.2 years, M −62.7%). Arterial stiffness was determined with an automated oscillometric device. All body composition parameters were assessed, based on bioelectrical impedance analysis (BIA), and laboratory parameters were obtained from the medical files of the patients. Results: We did not detect any significant difference in terms of arterial stiffness and PhA in RTRs undergoing different immunosuppressive regimens, based on CsA, Tac, or BELA. Age was an essential risk factor for greater arterial stiffness. The PhA was associated with age, BMI, time of dialysis before transplantation, and kidney graft function. Conclusion: No significant differences in arterial stiffness and PhA were observed in RTRs under different immunosuppressive regimens. While our data provide additional evidence for arterial stiffness and PhA in RTRs, more research is needed to fully explore these cardiovascular risk factors and the impact of different immunosuppressive regimens.

Urine transferrin as an early endothelial dysfunction marker in type 2 diabetic patients without nephropathy: a case control study

BACKGROUND

Albumin, along with other proteins, is abnormally eliminated via the urine during early stages of diabetic nephropathy. Moreover, endothelial dysfunction (ED) accompanying early diabetic nephropathy may develop even before microalbuminuria is detectable. Transferrin has a molecular weight comparable to albumin, whereas transferrinuria and microalbuminuria in a 24-h urine sample may comparably reflect early diabetic nephropathy. Whereas transferrin metabolism is related with ED during very early diabetic nephropathy has not been elucidated yet. This case-control study aimed to evaluate the relation between ED and urine transferrin, even before early diabetic nephropathy is present.

METHODS

Patients were enrolled from two study sites in Mexico City: Ticomán General Hospital (healthy controls); and a Specialized Clinic for the Management of the Diabetic Patient (cases). All patients provided written informed consent. The primary endpoint was the correlation between urinary transferrin concentration and ED measured in type 2 diabetic patients without albuminuria. ED was evaluated by ultrasonographic validated measurements, which included carotid intima-media thickness (CIMT) and flow mediated dilation (FMD). Plasma biomarkers included glycated hemoglobin, creatinine, cholesterol and triglycerides, as well as urine albumin, transferrin and evidence of urinary tract infection.

RESULTS

Sixty patients with type 2 Diabetes Mellitus (t2DM; n = 30) or without t2DM (n = 30), both negative for microalbuminuria, were recruited. The group with t2DM were older, with higher values of HbA1c and higher ED. This group also showed significant differences in urine transferrin and urine/plasma transferrin ratio, as compared with healthy controls (14.4 vs. 18.7 mg/mL, p = 0.04, and 74.2 vs. 49.5; p = 0.01; respectively). Moreover, urine transferrin correlated with higher CIMT values (r = 0.37, p = 0.04), being particularly significant for t2DM population. CIMT also correlated with time from t2DM diagnosis (r = 0.48, p < 0.001) and HbA1c (r = 0.48; p < 0.001).

CONCLUSION

Urine transferrin correlated with subclinical atherogenesis in patients with t2DM without renal failure, suggesting its potential to identify cardiovascular risk in patients at very early nephropathy stage without microalbuminuria.

Chronic Kidney Disease and Pulse Wave Velocity: A Narrative Review

Chronic kidney disease (CKD) is associated with excess cardiovascular mortality, resulting from both traditional and nontraditional, CKD-specific, cardiovascular risk factors. Nontraditional risk factors include the entity Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) which is characterised by disorders of bone and mineral metabolism, including biochemical abnormalities of hyperphosphatemia and hyperparathyroidism, renal osteodystrophy, and vascular calcification. Increased arterial stiffness in the CKD population can be attributed amongst other influences to progression of vascular calcification, with significant resultant contribution to the cardiovascular disease burden. Pulse wave velocity (PWV) measured over the carotid-femoral arterial segments is the noninvasive gold-standard technique for measurement of aortic stiffness and has been suggested as a surrogate cardiovascular end-point. A PWV value of 10 m/s or greater has been recommended as a suitable cut-off for an increased risk of cardiovascular mortality. CKD is a risk factor for an excessive rate of increase in aortic stiffness, reflected by increases in PWV, and increased aortic PWV in CKD shows faster progression than for individuals with normal kidney function. Patients with varying stages of CKD, as well as those on dialysis or with a kidney transplant, have different biological milieu which influence aortic stiffness and associated changes in PWV. This review discusses the pathophysiology of arterial stiffness with CKD and outlines the literature on PWV across the spectrum of CKD, highlighting that determination of arterial stiffness using aortic PWV can be a useful diagnostic and prognostic tool for assessing cardiovascular disease in the CKD population.