Mismatch between stiffness in elastic and muscular arteries as a predictor of vascular calcification in dialysis patients

The Relationship Between Bone Metabolism and Peripheral Artery Disease in Patients on Hemodialysis: The Potential Role of Osteocalcin

Introduction

To examine the factors associated with PAD, with a specific focus on bone metabolism factors such as osteocalcin.

Methods

This cross-sectional study examined factors about demographic, clinical, and laboratory parameters including bone metabolism biomarkers in hemodialysis patients. The ankle-brachial index (ABI) was measured in all patients, with PAD diagnosed as an ABI <0.9.

Results

Out of the 71 patients, PAD was found in 23 individuals. These patients had an average age of 63.5±13.0 years, with 59.2% being male. Compared to non-PAD patients, those with PAD were older, had a lower proportion of males, and had a higher prevalence of diabetes and coronary artery disease. Among the factors related to bone metabolism, only osteocalcin exhibited a significant increase in the PAD group compared to the non-PAD group.

Conclusion

PAD in patients on hemodialysis was independently linked to high levels of osteocalcin in the bloodstream, indicating the presence of bone metabolism disorders.

Statin Therapy for Hyperlipidemic Patients With Chronic Kidney Disease and End-Stage Renal Disease: A Retrospective Cohort Study Based on 925,418 Adults in Taiwan

Background: For non-dialysis patients with hyperlipidemia, statins may provide clinical benefits in reducing mortality risk; however, the optimal treatment for dialysis patients with hyperlipidemia remains debatable. We evaluated the mortality risks for hyperlipidemic patients with renal disorders associated with statin therapy (ST), using the insurance claims data of Taiwan. Methods: From hyperlipidemic patients diagnosed in 2000-2011, we identified 555,153 patients receiving statin treatment for at least 90 days continuously and 1,141,901 non-statin users, and then randomly selected, from both groups, the propensity score-matched subcohorts of statin users and nonusers in a 1:1 pair by renal function: 415,453 pairs with normal renal function , 43,632 pairs with chronic kidney disease (CKD), and 3,624 pairs with end-stage renal disease (ESRD). We compared the mortalities, by the end of 2016, from all causes, cancer, heart disease, and septicemia between statin users and non-users and between hydrophilic-statin users and lipophilic-statin users. The Cox method estimated ST users to non-user hazard ratios. The time-dependent model was also conducted as sensitivity analysis. Results: The mean ages were 58.7 ± 10.7, 64.2 ± 10.7, and 62.2 ± 10.8 years in normal renal function, CKD, and ESRD groups, respectively. Compared with non-users, statin users had reduced mortality risks from all causes for 32%-38%, from cancer for 37%-46%, from heart disease for 6%-24%, and from septicemia for 17%-21% in all three renal groups. The hydrophilic statin therapy was superior than the lipophilic statin therapy, particularly for reducing deaths from all-causes and cancer. The results under the time-dependent model were similar. Conclusion: Statin therapy is associated with reduced all-causes and non-cardiovascular mortality in ESRD patients.

The effects of progenitor and differentiated cells on ectopic calcification of engineered vascular tissues

Ectopic vascular calcification associated with aging, diabetes mellitus, atherosclerosis, and chronic kidney disease is a considerable risk factor for cardiovascular events and death. Although vascular smooth muscle cells are primarily implicated in calcification, the role of progenitor cells is less known. In this study, we engineered tubular vascular tissues from embryonic multipotent mesenchymal progenitor cells either without differentiating or after differentiating them into smooth muscle cells and studied ectopic calcification through targeted gene analysis. Tissues derived from both differentiated and undifferentiated cells calcified in response to hyperphosphatemic inorganic phosphate (Pi) treatment suggesting that a single cell-type (progenitor cells or differentiated cells) may not be the sole cause of the process. We also demonstrated that Vitamin K, which is the matrix gla protein activator, had a protective role against calcification in engineered vascular tissues. Addition of partially-soluble elastin upregulated osteogenic marker genes suggesting a calcification process. Furthermore, partially-soluble elastin downregulated smooth muscle myosin heavy chain (Myh11) gene which is a late-stage differentiation marker. This latter point, in turn, suggests that SMC may be switching into a synthetic phenotype which is one feature of vascular calcification. Taken together, our approach presents a valuable tool to study ectopic calcification and associated gene expressions relevant to clinical therapeutic targets.

The Role of Vascular Smooth Muscle Cells in Arterial Remodeling: Focus on Calcification-Related Processes

Arterial remodeling refers to the structural and functional changes of the vessel wall that occur in response to disease, injury, or aging. Vascular smooth muscle cells (VSMC) play a pivotal role in regulating the remodeling processes of the vessel wall. Phenotypic switching of VSMC involves oxidative stress-induced extracellular vesicle release, driving calcification processes. The VSMC phenotype is relevant to plaque initiation, development and stability, whereas, in the media, the VSMC phenotype is important in maintaining tissue elasticity, wall stress homeostasis and vessel stiffness. Clinically, assessment of arterial remodeling is a challenge; particularly distinguishing intimal and medial involvement, and their contributions to vessel wall remodeling. The limitations pertain to imaging resolution and sensitivity, so methodological development is focused on improving those. Moreover, the integration of data across the microscopic (i.e., cell-tissue) and macroscopic (i.e., vessel-system) scale for correct interpretation is innately challenging, because of the multiple biophysical and biochemical factors involved. In the present review, we describe the arterial remodeling processes that govern arterial stiffening, atherosclerosis and calcification, with a particular focus on VSMC phenotypic switching. Additionally, we review clinically applicable methodologies to assess arterial remodeling and the latest developments in these, seeking to unravel the ubiquitous corroborator of vascular pathology that calcification appears to be.

Should we calculate arterial stiffness gradient in middle-aged women with increased cardiovascular risk?

PURPOSE

The study was designed to evaluate clinical and laboratory determinants pulse wave velocity (PWV) ratio in women at the age of 50-65 years without overt cardiovascular disease but having elevated cardiovascular risk, such as hypertension, obesity, diabetes and hypercholesterolemia.

MATERIALS AND METHODS

We analyzed data from 1170 women enrolled in the national-wide primary prevention program. Univariate and multivariate linear regression analysis was used to establish independent risk factors in groups based on clinical data, laboratory values, and comorbidities. Arterial stiffness was evaluated using applanation tonometry technique (SphygmoCor). The PWV ratio was calculated by dividing cfPWV to crPWV.

RESULTS

In multivariate logistic regression analysis, age (OR = 1.109, p < .001), waist circumference (OR = 1.021, p = .001) and mean arterial pressure (OR = 1.031, p < .001) were found as independent clinical determinants of PWV ratio, while independent laboratory determinants were urine albumin to creatinine ratio (OR = 1.189, p = .010), triglycerides (OR = 1.161, p = .034), glucose (OR = 1.28, p = .001) and eGFR (OR = 0.998, p = .007). Diabetes (OR = 1.811, p = .029), hypertension (OR = 2.784, p = .042) and menopause (OR = 1.054, p = .018) were established as independent factors in comorbidities group. The analysis confirmed that PWV ratio (R² = 0.0667, p < .001), as well as carotid radial (R² = 0.0341, p < .001) and carotid femoral PWV (R² = 0.1752, p < .001) is affected by mean arterial blood pressure.

CONCLUSIONS

Age, abdominal obesity, blood pressure, triglycerides, glucose, kidney function parameters and menopause all are associated with PWV ratio. More importance to women with high cardiovascular risk should be given whilst screening and stratifying further progression of the disease.

Common Carotid Artery Calcification Impacts on Cognitive Function in Older Patients

INTRODUCTION

Cognitive impairment and dementia represent an emerging health problem. Cardiovascular (CV) risk factors contribute to cognitive impairment.

AIM

To investigate the effect of vascular calcification on cognitive impairment and dementia, independently of plaque and traditional CV risk factors.

METHODS

Four hundred and sixty-nine patients (age of 78.6 ± 6.1 years, 74.4% women) were studied. Traditional CV risk factors levels, cognitive function (MMSE), brain CT scan, and other vascular parameters were measured. Common Carotid Artery (CCA) plaque and calcification were evaluated by ultrasound.

RESULTS

CCA calcification was associated with a lower MMSE score than in subjects with no CCA calcification (23.7 ± 0.3 versus 25.5 ± 0.8; p = 0.015), after controlling for age, sex, education, blood pressure levels, diabetes, creatinine, lipid lowering therapy, neuroimaging alteration, and CCA plaque. Similarly, CCA calcification was associated with higher odds of dementia regardless of the presence of CCA plaque (OR 1.70, 95% CI 1.01-2.94, p < 0.05). This trend was not observed when stratifying patients according to the presence of CCA plaque.

CONCLUSION

CCA calcification is associated with cognitive impairment and dementia, independently of established CV risk factors and CCA plaque. The impact of arterial calcification on cognition seems largely independent of arterial stiffness.

Two years of maintenance hemodialysis has a pronounced effect on arterial stiffness progression

BACKGROUND

The change of aortic stiffness, but not the particular baseline value, plays a crucial role in estimating the patient risk with end-stage renal disease. Therefore, we aimed to analyze the evolution of central and peripheral arterial stiffness in hemodialysis population without previous cardiovascular events during a 2-year follow-up.

METHODS

60 hemodialysis patients (mean age 57.61 ± 13.01 years) were prospectively interviewed, and they underwent blood tests, chest X-ray for aortic calcification evaluation and pulse wave velocity (PWV) measurements at the baseline, after 6 months and after 2 years of observation period.

RESULTS

We found significant progression of aortic PWV (12.73 vs. 14.24 m/s, p = 0.032) and regression of brachial PWV (11.53 vs. 8.85 m/s, p < 0.001). CRP increase influenced evolution of aortic PWV (β = 0.331, p = 0.031, R² = 0.599). Higher β2-microglobulin values was related to the progression of aortic PWV (β = 0.219, p = 0.022, R² = 0.568). Mean arterial blood pressure had influence only on the short-term arterial stiffness evolution.

CONCLUSIONS

Patients on maintenance hemodialysis experience pronounced changes of arterial stiffness during the 2-year follow-up period. The progression of aortic stiffness is related to inflammatory response and particularly is influenced by β2-microglobulin concentration and aortic calcification.