Lateral lumbar X-ray assessment of abdominal aortic calcification in Australian haemodialysis patients

Association of plasma microRNA-16-5p and abdominal aortic calcification in maintenance hemodialysis patients

Recent studies have shown that microRNA-16-5p (miR-16-5p) plays a crucial role in the pathological mechanism of vascular calcification. Nevertheless, the expression profile of miR-16-5p in maintenance hemodialysis (MHD) patients who are predisposed to vascular calcification remains unknown. This study aims to investigate the potential associations between calcification risk and serum miR-16-5p expression among MHD patients. This cross-sectional study involved 132 MHD patients from the Dialysis Center of Beijing Friendship Hospital between 1 January 2019 and 31 December 2020. The degree of calcification in MHD patients was assessed using the Abdominal aortic calcification (AAC) score, and miR-16-5p expression was quantified using quantitative real-time polymerase chain reaction (qRT-PCR) with the 2-ΔΔCT method. Statistical analyses, including spearman correlation, linear regression and logistic regression analysis were used to explore the associations between laboratory parameters and AAC score. Calcifications were observed in 79(59.80%) patients. The linear regression showed a one-quartile decrease in miR-16-5p expression led to a significant increase in the AAC score by 5.336 (95% CI: 2.670-10.662, p = 0.000). Multivariate logistic regression analyses revealed that decreased miR-16-5p expression, reduced serum urea nitrogen, elevated white blood cell count, and longer dialysis vintage were significantly associated with an increased incidence of vascular calcification. The Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC) of the miR-16-5p-based logistic regression model was 0.842 (95% CI: 0.771-0.913, p = 0.000). There was an independent association between miR-16-5p expression and calcification degree. Lower miR-16-5p expression levels seem to be a potential risk factor of vascular calcification in MHD patients.

Analysis of risk factors for abdominal aortic calcification in dialysis patients and its influence on long-term recovery

This study investigated the risk factors of abdominal aortic calcification (AAC) in patients with stage 5 chronic kidney disease (CKD) and the effects of AAC and different dialysis methods on the 3-year survival rate of patients with stage 5 CKD. A retrospective cohort study was conducted on stage 5 CKD patients who received dialysis treatment. The general data were collected, and all fasting venous blood samples were harvested before the first dialysis to detect biochemical markers. The AAC was evaluated by lateral abdominal X-ray. The patients were followed up with a cut-off date of March 31, 2022, with all-cause mortality as the endpoint event. A total of 205 patients were included. multivariable Cox regression analysis confirmed that AAC (hazard ratio (HR) = 2.173, 95% CI 1.029-4.588, p = 0.042), advanced age (HR = 1.061, 95% CI 1.031-1.093, p < 0.001), duration of dialysis (HR = 1.015, 95% CI 1.007-1.032, p < 0.001), diabetes (HR = 3.966, 95% CI 2.164-7.269, p < 0.001), and hypertension (HR = 1.897, 95% CI 1.089-3.303, p = 0.024) were independent risk factors for 3-year mortality. However, peritoneal dialysis (HR = 0.366, 95% CI 0.165-0.812, p = 0.013), high albumin (HR = 0.882, 95% CI 0.819-0.950, p = 0.001), and high hemoglobin (HR = 0.969, 95% CI 0.942-0.997, p = 0.031) were protective factors for 3-year mortality in stage 5 CKD patients. Increased age, long-term dialysis, high level of intact parathyroid hormone, diabetes, and hypertension are closely related to the occurrence of AAC in patients with stage 5 CKD. In addition, AAC is an independent risk factor for all-cause mortality in patients with stage 5 CKD.

Significant associations between bone mineral density and vascular calcification in patients with different stages of chronic kidney disease

Introduction

Chronic kidney disease—mineral and bone disorders (CKD-MBD) is characterised by generalised vascular calcification (VC) and impaired bone health. We aimed to investigate the relationship between VC and bone mineral density (BMD) in CKD patients.

Methods

We performed a cross-sectional study of patients with different stages of CKD. For assessment of VC of abdominal aorta lateral lumbar X-rays (Kauppila score), the ankle-brachial index (ABI) and echocardiography were used. Total body densitometry provided BMD.

Results

Ninety patients (41% male, median age 64 years (range 29–87)) were included, of whom 41.1% had a Kauppila score > 1. Evidence of peripheral VC as measured by ABI was detected in 23.3% of cases. Lesions of the heart valves were found in 46.7% of patients. There was a significant association between high ABI and lesions of the heart valves. In the multivariate regression model to analyse the independent determinants of abdominal aorta calcification (AAC) and ABI, the BMD of the femoral neck was identified as significant for both (p = 0.001, p = 0.001). The total spine BMD was found to be significant for AAC (p = 0.001), and the BMD of spine L1-L4 and the ribs were found to be significant for ABI (p = 0.01, p = 0.002 respectively). In factorial regression analysis, where BMD was independent determinant, valvular calcification was significant for BMD of femur, femoral neck and total BMD. Age and tALP were inversely correlated with the BMD of femur and femoral neck.

Conclusions

Our work highlighted clinically important relationships between VC and bone mineral density (BMD) in CKD patients. We detected inverse relationships between AAC, high ABI and BMD. Secondly, BMD at certain bone sites (femur, femoral neck) and total BMD were associated with important lesions of heart valves. Thirdly, a significant association between a high ABI and lesions of the heart valves. We believe that the results of our study will help in the planning of future research and in current clinical practice for the early diagnosis, further monitoring and management of CKD-MBD. Additionally, these results may have treatment implications on use of different CKD-MBD medications.

Association of Serum Osteoprotegerin Level With Myocardial Injury and Cardiovascular Calcification in Chronic Kidney Disease Patients

Background

Chronic kidney disease has emerged as a significant independent risk factor for cardiovascular disease. Cardiovascular calcification is an active process involving a complex interaction of inducers and inhibitors. High sensitivity cardiac troponin T assay detects troponin T with higher sensitivity and precision at an earlier point of time than the conventional assays, and is associated with poor outcomes. Serum osteoprotegerin is classed as an inhibitory factor for cardiovascular calcification. It is involved in the pathological processes of vascular damage and linked to the excess cardiovascular morbidity. The aim of the present study was to evaluate the extent of cardiovascular calcification and serum high sensitivity cardiac troponin T level, and their association with serum osteoprotegerin level in patients with chronic kidney disease stages 3-5.

Methods

90 chronic kidney disease patients were enrolled in this study, and they were divided into two groups: group (1) included 45 non-dialysis-dependent chronic kidney disease patients (stages 3-5) and group (2) included 45 chronic hemodialysis patients. Each group further subdivided according to the presence of cardiovascular calcification into subgroup A and B. Vascular calcifications were assessed by lateral lumbar, pelvis and hands X-ray radiographs. Valvular calcification was assessed by echocardiography. Serum cardiac troponin T was measured by high sensitivity assay and serum osteoprotegerin was measured by ELISA.

Results

Cardiovascular calcification distribution was 22.2% in group (1) and 33.3% in group (2). Serum osteoprotegerin and troponin T in calcification groups (1A and 2A) were significantly higher than non-calcification groups (1B and 2B; P < 0.001). Osteoprotegerin correlated positively with high sensitivity cardiac troponin T (rs = 0.72, P < 0.001). cardiovascular calcification correlated positively with osteoprotegerin, troponin T, and phosphorus. osteoprotegerin and phosphorus were significant independent predictors of cardiovascular calcification at cut-off values ≥4.6 ng/L and ≥6.95 mg/dl, respectively (P < 0.001). Serum phosphorus and creatinine were independent predictors of osteoprotegerin (P < 0.001 and 0.048, respectively).

Conclusion

Osteoprotegerin is strongly associated with cardiovascular calcification and high sensitivity cardiac troponin T. In addition, there is a positive association between calcification and troponin T. This suggests a role for osteoprotegerin in the pathogenesis and risk stratification of cardiovascular calcification and myocardial injury in chronic kidney disease patients with a potential role as a therapeutic target.

Histopathological assessment of radial artery calcification in patients with end-stage kidney disease

Background

A comprehensive understanding of vascular calcification pathology is significant for the development of cardiovascular disease therapy in high-risk populations. This cross-sectional study aimed to evaluate the prevalence and characteristics of radial artery calcification (RAC) and to identify the factors that are associated with RAC in end-stage kidney disease (ESKD).

Methods

Detailed medical histories of 180 patients with ESKD were recorded. Fragments of the radial artery obtained during the creation of arteriovenous fistula for hemodialysis access were stained with alizarin red S.

Results

Calcification was localized in the arterial media layer. The prevalence of positive calcification staining in the radial arteries was 21.1% (n = 38). Patients with RAC had a higher glycated hemoglobin level (p < 0.01), higher prevalence of dialysis duration >5 years (p = 0.022), and diabetes mellitus (p < 0.01) than those without RAC. Multiple logistic regression models showed dialysis duration >5 years (odds ratio [OR], 9.864; 95% confidence interval [CI], 2.666–36.502; p < 0.01) and diabetes mellitus (OR, 12.689; 95% CI, 2.796–34.597; p < 0.01) were independent risk factors for RAC in patients with ESKD. Patients with dialysis duration >5 years had a higher prevalence of RAC (p = 0.012) than those with dialysis duration ≤5 years. Patients with diabetes mellitus had a higher prevalence of RAC (p < 0.01) than those without diabetes mellitus. Patients with diabetes mellitus ≥15 years had a higher prevalence of RAC (p = 0.042) than those with diabetes mellitus <15 years. Radial artery calcification level showed a significantly positive correlation with dialysis duration (p < 0.05), diabetes mellitus duration (p < 0.01), HbA1c level (p < 0.01) and Calcium level (p < 0.01).

Conclusions

In patients with ESKD, dialysis duration >5 years and diabetes predict RAC. Thus, the combination of prolonged dialysis and hyperglycemic conditions exerts a synergistic effect on RAC.

Association between Serum Zinc Levels and Clinical Index or the Body Composition in Incident Hemodialysis Patients

Background: The relationships between serum zinc levels and body composition or clinical outcomes of incident hemodialysis (HD) patients remain unclear. Methods: This prospective observational study examined the relationships between serum zinc levels and clinical indexes, including body composition, in 142 incident HD patients using a bioelectrical impedance analysis. Patients were divided into three groups according to baseline serum zinc levels: tertile, <45, 45–59, and ≥60 µg/dL. The reference group was set as ≥60 µg/dL. Cox’s regression analysis was performed to investigate the relationships between serum zinc categories and cardiovascular events and all-cause mortality after adjustments for potential confounders. Results: Serum zinc levels positively correlated with the nutritional index and negatively correlated with fluid volume markers. In a mean follow-up of 2.5 years, there were 20 cases of cardiovascular events and 15 of all-cause mortality. In the Cox’s regression analysis for cardiovascular events and all-cause mortality, the hazard ratio increased with a decrease in serum zinc levels, but was not significant. Conclusion: Serum zinc levels were associated with nutritional and fluid volume markers in incident HD patients. To clarify the relationship between serum zinc levels and cardiovascular events or mortality, further studies with a larger number of cases will be necessary.

Abdominal aortic calcification score as a predictor of clinical outcome in peritoneal dialysis patients: a prospective cohort study

Background

Abdominal aortic calcification assessed by X-ray is recommended to evaluate vascular calcification in dialysis patients. It has been shown that abdominal aortic calcification score (AACS) is a predictor of adverse outcomes in hemodialysis patients, but evidence regarding its prognostic value in peritoneal dialysis (PD) patients is still insufficient. We aimed to examine the predictive role of AACS for major adverse cardiac and cerebrovascular events (MACCE) and mortality in PD patients.

Methods

Eligible patients undergoing PD between July 2011 and July 2014 were recruited. AACS was quantified using lateral lumbar radiography at recruitment. Patients were prospectively followed up until death, PD cessation, or to the end of the study (August 31, 2018). Both subdistribution hazards and cause-specific hazards models were used to evaluate the association between AACS and MACCE as well as mortality.

Results

292 patients were enrolled, including 160 males (54.8%) with mean age 57.1 ± 15.2 years and median PD duration 28.4 (IQR 12.0, 57.8) months. Among them, 75 (25.7%) patients were comorbid with diabetes, and 94 (32.2%) patients had cardiovascular disease (CVD). The average AACS was 2.0 (0.0, 6.0). Patients were categorized on the tertiles of AACS (Low AACS group, AACS = 0, n = 125; Medium AACS group, AACS 1–4, n = 72; and High AACS group, AACS> 4, n = 95). AACS was associated with age (OR = 1.081, P < 0.001), PD duration (OR = 1.012, P = 0.003), CVD (OR = 1.919, P = 0.020) and diabetes (OR = 2.554, P = 0.002). During the follow-up period of 43.6 (24.6, 50.7) months, there were 65 MACCEs and 84 deaths. Significantly higher cumulative incidences of all-cause mortality (Log-rank = 35.992, P<0.001; Gray = 38.662, P < 0.001) and MACCE (Log-rank = 26.146, P<0.001; Gray = 27.810, P < 0.001) were observed in the upper AACS tertile. AACS was an independent predictor of all-cause mortality (HR = 2.438, 95% CI 1.246–4.772, P = 0.009; SHR = 2.323, 95%CI 1.229–4.389, P = 0.009) and MACCE (HR = 3.455, 95% CI 1.734–6.884, P < 0.001; SHR = 3.063, 95%CI 1.460–6.430, P = 0.003) in this study.

Conclusions

AACS was associated with age, PD duration, CVD and diabetes in PD patients. AACS could predict MACCE and all-cause mortality in this population. It thus might be a safe and feasible method to identify PD patients with adverse outcomes.

Abdominal aortic calcification score predicts the occurrence of coronary artery disease in middle-aged peritoneal dialysis patients

AIM

Abdominal aortic calcification (AAC) score in dialysis patients was associated with coronary artery disease (CAD) in cross-sectional study, but the use of AAC score in the CAD prediction was not clear. We aimed to use AAC score in the estimation of CAD occurrence in middle-aged peritoneal dialysis (PD) patients.

METHODS

Middle-aged (45-65 years old) PD patients were recruited and followed up until CAD occurrence, patient mortality, or PD failure. We quantified AAC score by lateral lumbar radiography, and used receiver operation curve (ROC) analysis to find the cut-off value for CAD prediction.

RESULTS

There were 187 patients recruited for study with a mean follow-up of 1027 ± 427 days. AAC score in patients with CAD during follow-up period (9.7 ± 7.6, n = 41) was higher than in patients without CAD occurrence (5.5 ± 6.1, n = 146) (P < 0.001). Multivariate hazard ratio of AAC score for CAD was 1.07 (P = 0.044). ROC showed that AAC score of 5.5 had a sensitivity of 0.667 and a specificity of 0.581 in the prediction of CAD occurrence. Patients with AAC score above 5.5 had significantly higher cumulative incidence of CAD than patients with AAC score below 5.5 (Log-rank test, P = 0.003). Age (P = 0.002), diabetes (P = 0.002), hypertension (P = 0.032), longer dialysis vintage (P < 0.001) and lower serum potassium (P = 0.012) were parameters significantly associated with higher AAC score.

CONCLUSION

AAC score can predict CAD occurrence in PD patients. Age, diabetes, hypertension, dialysis vintage and serum potassium level are factors associated with higher AAC score.

Relationship of Serum Soluble Klotho Levels and Echocardiographic Parameters in Patients on Maintenance Hemodialysis

Background: Cardiovascular disease is the leading cause of morbidity and mortality in maintenance hemodialysis (MHD) patients. Uremic cardiomyopathy, characterized by myocardial hypertrophy and fibrosis, has a significant contribution to these adverse cardiac outcomes. The protective effect of soluble Klotho (s-Klotho) on myocardial damage was demonstrated in in vitro and animal experiments. However, data from MHD patients is limited. The present study was designed to identify potential correlations between echocardiographic parameters and serum s-Klotho levels in MHD patients. Methods: This is a cross-sectional study involving 105 MHD patients from the Dialysis Center of Capital Medical University affiliated Beijing Friendship Hospital between March and October 2014. The general information for each patient was recorded. Fasting blood samples were collected prior to hemodialysis during the mid-week session in all patients. The echocardiogram and left lateral lumbar spine radiograph were performed after the same mid-week session. The dialysis records for each session within 3 months before the blood tests were documented. According to the quartiles of s-Klotho levels, patients were divided into four groups (Group 1–4). The demographic and clinical characteristics, echocardiographic parameters, and abdominal aortic calcification scores among the groups were compared. Results: The enrolled 105 patients were predominantly male (54.3%) with an average age of 59.9 ± 11.2 years. Previous hemodialysis durations were 76 (42–133) months. Sixteen (15.2%) patients had diabetes mellitus. Mean serum s-Klotho level was 411.83 ± 152.95 pg/mL, and the 25th percentile, 50th percentile, and 75th percentile values of serum s-Klotho levels were 298.9, 412, and 498.2 pg/mL, respectively. Individuals in the bottom quartile of s-Klotho levels (Group 1) had significantly increased interventricular septal thickness (IVST) compared to those in the other three quartiles of s-Klotho levels (Group 1: 1.12 ± 0.16 cm; vs. Group 2: 1.12 ± 0.16 cm, p = 0.008; vs. Group 3: 0.94 ± 0.13 cm, p < 0.001; vs. Group 4: 1.03 ± 0.1 5 cm, p = 0.022). There were significant differences in the ratios of IVST and posterior wall thickness (PWT) between patients of Group 1 and Group 3 (1.12 ± 0.1 2 vs. 1.00 ± 0.1 4, p = 0.004). No significant differences were found for other parameters among the groups. The univariate correlation analyses showed that gender (r = –0.211, p = 0.030), Kt/V urea (r = –0.240, p = 0.014), hypersensitive C reactive protein (hs-CRP) (r = 0.196, p = 0.045), and serum s-Klotho levels (r = –0.260, p = 0.007) significantly correlated with IVST. Ultimately, only hs-CRP and serum s-Klotho levels were entered into a multiple regression model. Conclusions: The present study showed that patients with lower circulating s-Klotho levels were more often associated with larger IVST and greater ratios of IVST and PWT. There was an independent association between s-Klotho and IVST, and lower s-Klotho levels seem to be a potential risk factor of uremic cardiomyopathy in MHD patients.

High Fetuin-A Level as a Protective Factor to Abdominal Aortic Calcification in Indonesian Regular Hemodialysis Patients

BACKGROUND:

Although the prevalence of cardiovascular disease decreases in the general population, this pattern is not followed in hemodialysis patients. Hence cardiovascular events still occur in 50% of cases resulting in hemodialysis patients. One of the risk factors is vascular calcification. The pathogenesis is not yet fully understood, but recent years studies have shown that vascular calcification in chronic kidney disease (CKD) occurs as a result of the interaction of stimulatory and inhibitory factors. One of the inhibitory factors is Fetuin-A. Until now there has been no data on levels of Fetuin-A as a risk factor for abdominal aortic calcification in Indonesia.

AIM:

To determine the effect of Fetuin-A levels on abdominal aortic calcification in regular hemodialysis patients.

METHODS:

This study was a cross-sectional study on 76 regular hemodialysis patients at Rasyida Renal Hospital Medan. Fetuin-A level was examined by enzyme-linked immunosorbent assay (ELISA). Assessment of abdominal aortic calcification was done by lateral lumbar X-ray.

RESULTS:

Most patients (68.4%) had abdominal aortic calcification, in both layers; intima and media (44.7%). Abdominal aortic calcification was associated with Fetuin-A level and age. Multivariate analysis showed that high Fetuin-A levels were significantly associated with abdominal aortic calcification.

CONCLUSION:

High Fetuin-A level appeared to be a protective factor against abdominal aortic calcification in regular hemodialysis patients in Indonesia.

Aortic vascular calcification is inversely associated with the trabecular bone score in patients receiving dialysis

INTRODUCTION

Progressive chronic kidney disease (CKD) confers a marked increase in risk for vascular calcification, cardiovascular disease, fracture and mortality, with likely contributing factors including dysregulated bone metabolism and mineral homeostasis. In general population studies, increased vascular calcification is directly related to mortality and inversely related to bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). In patients with CKD, abnormalities in turnover, mineralization and bone volume reduce the ability of DXA to predict fracture. The trabecular bone score (TBS) obtained from lumbar spine DXA images, provides a surrogate measure of microarchitectural integrity not captured by BMD. This study aimed to examine the association of the TBS to prevalent abdominal aortic calcification (AAC) in patients with CKD receiving dialysis.

METHODS

We performed a cross-sectional study of dialysis patients awaiting transplantation. All patients underwent laboratory testing, lateral spinal radiographs including the abdominal aorta, DXA imaging and TBS assessment. AAC scores were determined using the Kauppila method. Correlations and linear regression models were used to determine predictors of AAC scores.

RESULTS

146 patients (60% male, mean age 48 ± 13 years) were included, of whom 49% had prevalent calcification with an AAC score ≥ 1. Of those with calcification, the mean AAC score was 7 ± 5.5 and 42 patients had scores ≥ 6, considered to indicate severe AAC. TBS values corresponding to intermediate or high risk for fracture (<1.31) were present in 35% of patients. TBS values correlated inversely to AAC scores (β = -0.206, p = 0.013) and remained significant in multivariable linear regression, adjusting for age, BMI and time on dialysis (-0.160, p = 0.031). There was no significant correlation of AAC scores to any BMD parameter.

CONCLUSION

There is a high prevalence of AAC in relatively young dialysis patients awaiting transplantation and their AAC scores are inversely related to the TBS but not to DXA-derived BMD parameters. In patients with CKD on dialysis, TBS assessment reflects microarchitectural abnormalities of bone not captured by DXA. The inverse relationship of TBS to vascular calcification may provide insights into bone-vascular interactions in CKD.

Diabetes and Abdominal Aortic Calcification-a Systematic Review

PURPOSE OF REVIEW

A systematic literature review was performed to evaluate diabetes mellitus (DM) as a risk factor of abdominal aortic calcification (AAC), and address factors that might contribute to the development of AAC in DM patients.

RECENT FINDINGS

DM is an independent risk factor of AAC development. Bone metabolism along with lifestyle factors among DM patients makes them more prone to AAC. Hip and vertebral fractures, high phosphate, smoking, hypertension, and low osteocalcin could make DM patients prone to AAC. Low levels of high-density lipoprotein (HDL), high low-density lipoprotein (LDL), high total cholesterol/HDL ratio, low bone mineral density (BMD) may be risk factors, but the literature is more ambiguous. Body mass index (BMI) does not appear to increase risk of AAC. High phosphate levels and low osteocalcin levels seem to be biomarkers of AAC in patients with diabetes. However, the association between DM and AAC is complicated.

Abdominal aorta and pelvic artery calcifications on plain radiographs may predict mortality in chronic kidney disease, hemodialysis and renal transplantation

PURPOSE

Vascular calcification is common in chronic kidney disease (CKD) and predicts poor patient outcomes. While computed tomography is the gold standard for evaluation of vascular calcification, plain radiograph offers a simpler and less costly alternative. The calcification of abdominal aorta, iliac and femoral arteries has been evaluated by plain radiograph, but the data on their outcome predictabilities are still limited. The present study investigated the role of abdominal aortic calcification (AAC) and pelvic arterial calcification (PAC) in predicting overall morality in non-dialysis CKD stages 2-5 (CKD 2-5), maintenance hemodialysis (HD) and long-term kidney transplant (KT) patients.

METHODS

Four hundred and nineteen patients were included. Lateral abdominal and pelvic radiographs were obtained. The degree of AAC and PAC was evaluated according to the methods described previously by Kaupplia et al. and Adragao et al. Patients were followed prospectively for 5 years.

RESULTS

AAC and PAC scores correlated well with the correlation coefficients of 0.442 for CKD 2-5, 0.438 for HD and 0.586 for KT (p < 0.001). Patients with AAC score > 6 or PAC score > 1 were older, showed higher prevalence of DM and had higher serum phosphate and PTH but lower serum albumin and eGFR. A more severe degree of AAC was associated with an increase in KT duration, whereas a more severe degree of PAC was associated with worsening kidney function and prolonged dialysis vintage. Kaplan-Meier survival curves revealed AAC score > 6 as a significant predictor of all-cause mortality in CKD 2-5 but not in HD or KT, whereas PAC score > 1 was a significant predictor of all-cause mortality in all three populations. After adjusting for age, the predictability of AAC was lost, whereas PAC remained an independent predictor of mortality in all three populations. Adjustments for cardiovascular and CKD risk factors including age, gender, BMI, DM, serum albumin, calcium and phosphate attenuated the predictability of PAC in HD but not in CKD 2-5 or KT patients.

CONCLUSION

PAC was better than AAC in predicting mortality in CKD, HD and KT patients.

Prevalence of abdominal artery calcification in dialysis patients with end-stage renal disease: a systematic review and meta-analysis

PURPOSE

To systematically determine the prevalence of abdominal artery calcification (AAC) in dialysis patients with end-stage renal disease (ESRD) and identify reasons for heterogeneity.

METHODS

We searched PubMed, EMBASE, and Web of Science from database inception to March 2017. Cross-sectional or cohort (only used baseline data) studies reporting estimates of AAC prevalence in dialysis adult patients with ESRD were included. We performed a random-effects meta-analysis to generate pooled prevalence estimates. Subgroup analyses were used to compare differences within categorical variables (geographic region, AAC detection instruments, dialysis methods, study design, and sample size), and meta-regression analyses to assess the impact of continuous variables (participants' age, duration of dialysis, and male proportion).

RESULTS

A total of 44 studies with 9883 dialysis patients were included. The pooled prevalence for AAC was 68.5% (95% CI 63-73.9%). Subgroup analyses suggested that AAC prevalence varied significantly by geographical region and AAC detection instruments, not by dialysis methods, study design and sample size. Meta-regression analysis suggested that positive correlations were found between AAC prevalence and the age of participants as well as the male proportion (r = 1.01477, P = 0.002 and r = 2.034413, P = 0.01, respectively), but not with the duration of dialysis (P = 0.576).

CONCLUSION

The pooled and nearest estimate of AAC prevalence among dialysis patients was as high as 65%. Geographical region, AAC detection instruments, age of participants, and male proportion potentially lead to the high variance of the reported prevalence. Considering the high AAC prevalence, effective treatment for preventing vascular calcification in these patients is badly needed.

Relationship between serum osteoprotegerin and vascular calcifications in hemodialysis patients

BACKGROUND

Uremia is a vasculopathic process, and both cardiac calcification and vascular calcification seen from the early stages of chronic kidney disease. Osteoprotegerin could play a crucial role in atherosclerotic plaque formation, maturation and calcification. The goal of this study was to determine the relationship of serum osteoprotegerin with vascular calcification in patients with end stage kidney disease who were maintained on regular hemodialysis.

METHODS

Sixty clinically stable chronic renal failure patients undergoing regular hemodialysis were enrolled in this cross sectional study. Thirty patients (mean age 56.7 ± 10.5 years) with abdominal aortic calcification were selected by basal abdominal X-ray who underwent multi-slice computerized tomography scan to measure coronary artery calcification score; and thirty patients (mean age 56.5 ± 8.4 years) without abdominal aortic calcification. All patients were evaluated by serum calcium, phosphorus, albumin, lipid profile, intact parathyroid hormone (iPTH), serum creatinine, serum urea, serum uric acid, serum C-reactive protein, and hemoglobin. Serum osteoprotegerin samples were collected before dialysis and estimated by the ELISA kit.

RESULTS

Serum osteoprotegerin level was significantly higher in patients with vascular calcification than in those without calcifications. Serum osteoprotegerin correlated positively with serum phosphorus, calcium phosphorus product, alkaline phosphatase, iPTH, C-reactive protein, serum uric acid, low-density lipoprotein (LDL) and left ventricular mass index (LVMI) (p < 0.005), and negatively with hemoglobin, ejection fraction (p < 0.005) and HDL (p < 0.05).

CONCLUSIONS

These findings suggest that osteoprotegerin may be involved in the development of vascular calcification in hemodialysis patients.

Aortic Artery and Cardiac Valve Calcification are Associated with Mortality in Chinese Hemodialysis Patients: A 3.5 Years Follow-up

BACKGROUND

This study was to investigate the relationship among aortic artery calcification (AAC), cardiac valve calcification (CVC), and mortality in maintenance hemodialysis (MHD) patients.

METHODS

All MHD patients in Shanghai Ruijin Hospital in July 2011 were included. To follow up for 42 months, clinical data, predialysis blood tests, echocardiography, and lateral lumbar X-ray plain radiography results were collected. Plasma FGF23 level was measured using a C-terminal assay.

RESULTS

Totally, 110 MHD patients were involved in this study. Of which, 64 (58.2%) patients were male, the mean age was 55.2 ± 1.4 years old, and the median dialysis duration was 29.85 (3.0-225.5) months. About 25.5% of the 110 MHD patients had CVC from echocardiography while 61.8% of the patients had visible calcification of aorta from lateral lumbar X-ray plain radiography. After 42 months follow-up, 25 (22.7%) patients died. Kaplan-Meier analysis showed that patients with AAC or CVC had a significant greater number of all-cause and cardiovascular deaths than those without. In multivariate analyses, the presence of AAC was a significant factor associated with all-cause mortality (hazard ratio [HR]: 3.149, P = 0.025) in addition to lower albumin level and lower 25-hydroxy Vitamin D (25(OH)D) level. The presence of CVC was a significant factor associated with cardiovascular mortality (HR: 3.800, P = 0.029) in addition to lower albumin level and lower 25(OH)D level.

CONCLUSION

Lateral lumbar X-ray plain radiography and echocardiography are simple methods to detect AAC and CVC in dialysis patients. The presence of AAC and CVC was independently associated with mortality in MHD patients. Regular follow-up by X-ray and echocardiography could be a useful method to stratify mortality risk in MHD patients.

Assessment of abdominal aortic calcification at different stages of chronic kidney disease

PURPOSE

Vascular calcifications that may cause cardiovascular disease are highly prevalent in chronic kidney disease (CKD). In this study, we aimed to determine abdominal aorta calcifications (AAC) in predialysis and hemodialysis patients by lateral lumbar radiography and to investigate factors that were associated with the calcifications.

METHODS

Two hundred and fifty-nine adult chronic hemodialysis patients, 300 predialysis CKD patients and 60 healthy subjects with normal kidney function as a control group were enrolled in the study. Lateral lumbar radiography was used to measure AAC. Calcified deposits of the abdominal aorta wall at the level of the first through fourth lumbar vertebrae were graded by a 24-point scoring system.

RESULTS

AAC prevalence (AAC score ≥1) was significantly different in hemodialysis, predialysis and control groups (71.8, 45.7 and 33.3 %, respectively; p < 0.001). AAC prevalence in CKD stages 1, 2, 3, 4 and 5 predialysis patients was 26.6, 43.3, 40, 58.3 and 55 %, respectively. AAC scores of the hemodialysis group were higher than of the predialysis group (p < 0.001) and the control group (p < 0.001). AAC scores of the predialysis group were not higher than of the control group (p = 0.314). AAC scores of the hemodialysis group were significantly higher than of the control group (p < 0.001) and stage 1 (p < 0.001), stage 2 (p = 0.001) and stage 3 predialysis groups (p = 0.002). Age (p < 0.001), presence of diabetes mellitus (p < 0.001) and serum phosphorus levels (p = 0.011) were found to be independent predictors of calcification in the hemodialysis group. Age (p < 0.001), serum phosphorus levels (p = 0.007) and history of cardiovascular disease (p = 0.014) were found to be independent predictors of calcification in the predialysis group.

CONCLUSIONS

Abdominal aortic calcification is highly prevalent in the hemodialysis population. Strict phosphorus control should be implemented to the predialysis and hemodialysis patients.

Abdominal aortic calcification in patients with CKD

Background

Abdominal aortic calcification (AAC) is independently associated with cardiovascular events in dialysis patients and in the general population. However, data in non-dialysis chronic kidney disease (CKD) patients are limited. We analyzed determinants and prognostic value of AAC in non-dialysis CKD patients.

Methods

We included patients with CKD not receiving renal replacement therapy from the MASTERPLAN study, a randomized controlled trial that started in 2004. In the period 2008–2009, an X-ray to evaluate AAC was performed in a subgroup of patients. We studied AAC using a semi-quantitative scoring system by lateral lumbar X-ray. We used baseline and 2-year data to find determinants of AAC. We used a composite cardiovascular endpoint and propensity score matching to evaluate the prognostic value of AAC.

Results

In 280 patients an X-ray was performed. In 79 patients (28 %) the X-ray showed no calcification, in 62 patients (22 %) calcification was minor (<4), while 139 patients (50 %) had moderate or heavy calcification (≥4). Older age, prior cardiovascular disease, higher triglyceride levels, and higher phosphate levels were independent determinants of a calcification score ≥4. AAC score ≥4 was independently associated with cardiovascular events, with a hazard ratio of 5.5 (95 % confidence interval 1.2–24.8).

Conclusions

Assessment of AAC can identify CKD patients at higher cardiovascular risk, and may provide important information for personalized treatment. Whether this approach will ultimately translate into better outcomes remains to be answered.

Electronic supplementary material

The online version of this article (doi:10.1007/s40620-015-0260-7) contains supplementary material, which is available to authorized users.

Vascular calcification in long-term kidney transplantation

AIM

Vascular calcification (VC) is common among patients with chronic kidney disease (CKD) due to the strong prevalence of cardiovascular and CKD-related risk factors such as diabetes mellitus (DM), hypertension and phosphate retention. Kidney transplantation improves kidney function and abnormal mineral metabolism at the same time. It remains unclear whether kidney transplantation favourably impacts VC in the long-term.

METHODS

The present study examined VC in 132 kidney transplant (KT) recipients who had been transplanted for longer than one year. The severity of VC was compared to 129 CKD stages 5-5D patients on a kidney transplant (KT) waiting list.

RESULTS

The median KT vintage was 88 months. The prevalence of VC among KT and CKD patients were 54.5% and 62.8%, respectively, (P = 0.2). There were no differences in age, gender, body mass index (BMI), the prevalence of DM or CVD between the two groups. Among patients with calcification, a more severe degree was observed in KT recipients (P = 0.01). Aging, DM, CVD and dialysis vintage were associated with significant VC in both groups. The degree of VC in KT recipients was more pronounced than that in CKD patients among those who experienced prolonged dialysis vintage (>2 years) (P = 0.04). Among KT recipients, the severity of VC increased with the length of time after transplantation and became more substantial after 5 years.

CONCLUSIONS

Long-term KT recipients demonstrated a more severe degree of VC compared to matched CKD stages 5-5D patients. The severity of VC became more pronounced among those with longer transplant vintage and was in part influenced by past dialysis experience.

Fibroblast growth factor 23 is a predictor of aortic artery calcification in maintenance hemodialysis patients

BACKGROUND

Our study aimed to investigate the factors associated with elevated plasma FGF23 (cFGF23) levels in maintenance hemodialysis (MHD) patients and to determine whether plasma FGF23 level is related to aortic artery calcification (AAC).

METHODS

This study included 120 MHD patients and 20 controls. The FGF23 level was measured using a C-terminal assay and AAC was detected by a lateral lumbar X-ray plain.

RESULTS

Plasma FGF23 levels were significantly higher among dialysis patients compared to controls: FGF23 level of 27691.42 ± 55646.41 RU/mL in MHD patients versus 49.89 ± 23.94 RU/mL in health people. Significant correlations were observed between FGF23 levels and vintage, intact parathyroid hormone (iPTH), serum phosphate, total calcium, 25(OH)D, urea nitrogen (BUN), and serum creatinine (SCR). Stepwise multiple regression analysis showed that the independent parameters associated with FGF23 level were serum phosphate, total calcium, parathyroid hormone (PTH), SCR, and prealbumin. There were 73 patients (60.83%) with visible calcification in the abdominal aorta. Bivariate analysis showed that AAC score correlated with FGF23, phosphate, total calcium, vintage, age, and diastolic blood pressure. Forward logistic analysis showed that the independent parameters associated with AAC were age, total protein, and Lg FGF23.

CONCLUSION

Plasma FGF23 level is significant increased in hemodialysis patients and is independently associated with AAC.

CKD-MBD after kidney transplantation

Successful kidney transplantation corrects many of the metabolic abnormalities associated with chronic kidney disease (CKD); however, skeletal and cardiovascular morbidity remain prevalent in pediatric kidney transplant recipients and current recommendations from the Kidney Disease Improving Global Outcomes (KDIGO) working group suggest that bone disease-including turnover, mineralization, volume, linear growth, and strength-as well as cardiovascular disease be evaluated in all patients with CKD. Although few studies have examined bone histology after renal transplantation, current data suggest that bone turnover and mineralization are altered in the majority of patients and that biochemical parameters are poor predictors of bone histology in this population. Dual energy X-ray absorptiometry (DXA) scanning, although widely performed, has significant limitations in the pediatric transplant population and values have not been shown to correlate with fracture risk; thus, DXA is not recommended as a tool for the assessment of bone density. Newer imaging techniques, including computed tomography (quantitative CT (QCT), peripheral QCT (pQCT), high resolution pQCT (HR-pQCT) and magnetic resonance imaging (MRI)), which provide volumetric assessments of bone density and are able to discriminate bone microarchitecture, show promise in the assessment of bone strength; however, future studies are needed to define the value of these techniques in the diagnosis and treatment of renal osteodystrophy in pediatric renal transplant recipients.