Maria Vittoria Arcidiacono

Large Artery Calcification on Dialysis Patients Is Located in the Intima and Related to Atherosclerosis

BACKGROUND AND OBJECTIVES Vascular calcification (VC) has a significant effect in cardiovascular diseases on dialysis patients. However, VC is assessed with x-ray-based techniques, which do not inform about calcium localization (intima, media, atherosclerosis-related). The aim of this work is to study VC and its related factors using arterial ultrasound to report the exact location of calcium. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This was an observational, cross-sectional, case-control study that included 232 patients in dialysis and 208 age- and sex-matched controls with normal kidney function. Demographic data and laboratory values were collated. Carotid, femoral, and brachial ultrasounds were performed to assess VC and atherosclerosis burden using a standardized protocol. RESULTS Cardiovascular risk factors were predominantly found in controls, although the burden of atherosclerosis was higher in the dialysis group. VC was significantly more prevalent in the group of patients on dialysis than control subjects, and in both groups the most prevalent pattern of VC was linear calcification located in the intima of the artery wall. Age and undergoing dialysis (with or without previous cardiovascular diseases) were positively and significantly associated with linear calcification. Conversely, the absence of atherosclerosis and low levels of C-reactive protein and phosphorus significantly impeded the development of linear calcification. CONCLUSIONS VC in large, conduit arteries is more prevalent in patients on dialysis than controls and is predominantly located in a linear fashion in the intima of the arteries.

Prevalence of subclinical atheromatosis and associated risk factors in chronic kidney disease: the NEFRONA study

BACKGROUND The causes of the high cardiovascular mortality observed in chronic kidney disease (CKD) are unknown. Here, we report data on prevalence of subclinical atherosclerosis in the NEFRONA population and a stratified multivariate logistic analysis of factors associated with the presence of plaque. METHODS We analysed 2445 patients with an estimated glomerular filtration rate (eGFR) <60 mL/min (CKD 3: 937; CKD 4-5: 820; CKD 5D: 688) and 559 non-CKD subjects (eGFR >60 mL/min), 18-75 years old, without previous cardiovascular events. An itinerant team of professionals performed carotid and femoral arterial ultrasound. RESULTS The already high prevalence of plaques in CKD 3 is even higher in more severe CKD. Multivariate logistic analysis showed that, at any CKD stage, age and being male are independently associated with the presence of plaques. In CKD 3, there was a significant interaction of the smoking status and triglycerides levels which were independently associated with the presence of plaque. Furthermore, being diabetic was also associated with the presence of subclinical atherosclerosis. In stage 4-5 there was a significant association with smoking, high phosphate and hsCRP levels. In dialysis patients, being diabetic, having low levels of 25(OH)-vitamin D3 and smoking status also showed a significant association with the presence of plaque. Furthermore, the association of phosphate levels with the presence of subclinical atheromatosis showed a U-shaped curve. CONCLUSIONS This analysis demonstrates the magnitude of subclinical atheromatous disease in a large CKD population. The patient characteristics associated with the presence of plaque differ in every CKD stage.

Microangiopathy of large artery wall: A neglected complication of diabetes mellitus

OBJECTIVE To test the concept that diabetic patients with microangiopathy of the retinal microcirculation would also show an involvement of the carotid adventitial microcirculation, we aimed to assess the status of the vasa vasorum (VV) signal, measured by contrast-enhanced carotid ultrasound imaging, in type 2 diabetic patients with and without retinopathy. METHODS AND RESULTS Using contrast-enhanced ultrasound imaging, we quantified the signal of the VV of the common carotid artery. We investigated two subgroups of type 2 diabetic patients who did not have previous cardiovascular disease: 51 with retinopathy and 56 without retinopathy. The reference VV signal was measured in a group of 65 healthy volunteers as the ratio of the contrast agent signal of the VV and that of the lumen of the artery. Patients and volunteers also underwent a clinical evaluation. The reference VV signal in the group of 65 healthy volunteers was 0.562 (SD = 0.142). Patients with diabetic retinopathy showed a higher mean adventitial VV signal (0.700; SD = 0.150) than those without retinopathy (0.621; SD = 0.120) (P < 0.0039). This difference remained highly significant after adjusting for cardiovascular risk factors. Common carotid intima-media thickness and carotid plaque prevalence were not different between diabetic subgroups. CONCLUSIONS Type 2 diabetic patients with retinopathy show increased angiogenesis of the VV of the common carotid artery. This suggests the existence of a diabetic microangiopathic complication affecting the wall of the large arteries that may be an important contributor to the cardiovascular disease burden in diabetes mellitus.

Role of local bioactivation of vitamin D by CYP27A1 and CYP2R1 in the control of cell growth in normal endometrium and endometrial carcinoma

Vitamin D (VD) deficiency has been suggested as a risk factor for cancer. One recognized mechanism is that the low-serum 25-hydroxyvitamin D (25(OH)D) of VD deficiency reduces intratumoral 25(OH)D conversion to 1α,25-dihydroxyvitamin D (1,25D, the hormonal form of VD), compromising 1,25D-VD receptor (VDR) antitumoral actions. Reduced tumoral VDR and increased CYP24A1, the enzyme that degrades 1,25D and 25(OH)D, further worsen cancer progression. Importantly, in cells expressing CYP27A1 and/or CYP2R1, which convert inert VD into 25(OH)D, low-serum VD may reduce intratumoral 25(OH)D synthesis thereby compromising VDR antitumoral actions because 25(OH)D can activate the VDR directly and enhance 1,25D-VDR action. Therefore, this study examined whether abnormal endometrial expression of CYP27A1 and/or CYP2R1 may impair VDR-antiproliferative properties in endometrial carcinoma (EC). Immunohistochemical analysis of tissue microarrays of normal human endometrium (NE; n=60) and EC (n=157) showed the expected lower VDR expression in EC (P=0.0002). Instead, CYP24A1 expression was lower in EC compared with NE, while CYP27A1 and CYP2R1 expressions were higher (P=0.0002; P=0.03). Furthermore, in NE and EC, CYP2R1 and CYP27A1 expression correlated directly with nuclear VDR levels, an indicator of ligand-induced VDR activation, and inversely with the proliferation marker Ki67. Accordingly, in the endometrioid carcinoma cell lines IK, RL95/2 and HEC1-A, which express VDR, CYP27A1, and CYP2R1, VD efficaciously reduced cell viability and colony number, with a time course that paralleled actual increases in both intracellular 25(OH)D and nuclear VDR levels. Thus, VD may protect from EC progression in part through increased intratumoral 25(OH)D production by CYP27A1 and CYP2R1 for autocrine/paracrine enhancement of 1,25D-VDR-antiproliferative actions.

Increased Burden of Cerebral Small Vessel Disease in Patients With Type 2 Diabetes and Retinopathy.

OBJECTIVE We sought to examine the presence and severity of brain small vessel disease (SVD) in patients with type 2 diabetes and diabetic retinopathy (DR) compared with those without DR. RESEARCH DESIGN AND METHODS We evaluated 312 patients with type 2 diabetes without previous cardiovascular disease (men 51%; mean age 57 years; age range 40–75 years); 153 patients (49%) had DR. MRI was performed to evaluate the presence and severity (age-related white matter changes scale) of white matter lesions (WMLs) and lacunes, and transcranial Doppler ultrasound was used to measure the Gosling pulsatility index (PI) of the middle cerebral artery (MCA). RESULTS The prevalence of lesions of cerebral SVD (WML and/or lacunes) was higher in patients with DR (40.2% vs. 30.1% without DR, P = 0.04). Age (P < 0.01) and systolic blood pressure (P = 0.02) were associated with the presence of SVD. The severity of SVD was associated with age and the presence of DR (P < 0.01 and P = 0.01, respectively). Patients with DR showed a higher MCA PI compared with those without DR (P < 0.01). Age, systolic and diastolic blood pressure, and retinopathy and its severity were associated with an increased MCA PI (P < 0.01 for all variables). A positive correlation was found between MCA PI values and the presence and severity of SVD (P < 0.01 for both variables). CONCLUSIONS Patients with type 2 diabetes who have DR have an increased burden of cerebral SVD compared with those without DR. Our findings suggest that the brain is a target organ for microangiopathy, similar to other classic target organs, like the retina.

Left carotid adventitial vasa vasorum signal correlates directly with age and with left carotid intima-media thickness in individuals without atheromatous risk factors

ObjectiveThe early identification of the onset of subclinical atheromatosis is essential in reducing the high mortality risk from cardiovascular disease (CVD) worldwide. Although carotid intima-media thickness (cIMT) is the most commonly used early predictor of ongoing atherosclerosis, an experimental model of atherosclerosis, demonstrated that increases in adventitial microvessels (vasa vasorum (VV)) precede endothelial dysfunction. Using the reported accuracy of contrast-enhanced ultrasound (CEU) to measure carotid adventitial VV, this study assessed whether measurements of carotid adventitial VV serve as a marker of subclinical atherosclerotic lesions in a control population with none of the classical risk factors for CVD.Methods and resultsMeasurements of cIMT (B-mode ultrasound) and adventitial VV (CEU) were conducted in 65 subjects, 30–70 years old, 48% men, with none of the classical risk factors for CVD. Adventitial VV strongly correlated with its own cIMT only in the left carotid artery. Importantly, the left carotid adventitial VV directly correlated with age.ConclusionsThe increases with age in left carotid adventitial VV in individuals with zero risk for atheromatosis suggest that the measurement of carotid adventitial VV could be an accurate and sensitive marker for the diagnosis of subclinical atheromatosis and therefore a prominent tool for monitoring the efficacy of anti-atheromatous therapies.

Vascular Calcification Induced by Chronic Kidney Disease Is Mediated by an Increase of 1α-Hydroxylase Expression in Vascular Smooth Muscle Cells

Vascular calcification (VC) is a complication of chronic kidney disease that predicts morbidity and mortality. Uremic serum promotes VC, but the mechanism involved is unknown. A role for 1,25(OH)2D3 in VC has been proposed, but the mechanism is unclear because both low and high levels have been shown to increase it. In this work we investigate the role of 1,25(OH)2D3 produced in vascular smooth muscle cells (VSMCs) in VC. Rats with subtotal nephrectomy and kidney recipient patients showed increased arterial expression of 1α‐hydroxylase in vivo. VSMCs exposed in vitro to serum obtained from uremic rats also showed increased 1α‐hydroxylase expression. Those increases were parallel to an increase in VC. After 6 days with high phosphate media, VSMCs overexpressing 1α‐hydroxylase show significantly higher calcium content and RUNX2 expression than control cells. 1α‐hydroxylase null mice (KO) with subtotal nephrectomy and treated with calcitriol (400 ng/kg) for 2 weeks showed significantly lower levels of vascular calcium content, Alizarin red staining, and RUNX2 expression than wild‐type (WT) littermates. Serum calcium, phosphorus, blood urea nitrogen (BUN), PTH, and 1,25(OH)2D3 levels were similar in both calcitriol‐treated groups. In vitro, WT VSMCs treated with uremic serum also showed a significant increase in 1α‐hydroxylase expression and higher calcification that was not observed in KO cells. We conclude that local activation of 1α‐hydroxylase in the artery mediates VC observed in uremia.

A Novel Rat Model of Vitamin D Deficiency: Safe and Rapid Induction of Vitamin D and Calcitriol Deficiency without Hyperparathyroidism

Vitamin D deficiency is associated with a range of clinical disorders. To study the mechanisms involved and improve treatments, animal models are tremendously useful. Current vitamin D deficient rat models have important practical limitations, including time requirements when using, exclusively, a vitamin D deficient diet. More importantly, induction of hypovitaminosis D causes significant fluctuations in parathyroid hormone (PTH) and mineral levels, complicating the interpretation of study results. To overcome these shortcomings, we report the successful induction of vitamin D deficiency within three weeks, with stable serum PTH and minerals levels, in Wistar rats. We incorporated two additional manoeuvres compared to a conventional diet. Firstly, the vitamin D depleted diet is calcium (Ca) enriched, to attenuate the development of secondary hyperparathyroidism. Secondly, six intraperitoneal injections of paricalcitol during the first two weeks are given to induce the rapid degradation of circulating vitamin D metabolites. After three weeks, serum 25-hydroxyvitamin D3 (25D) and 1,25-dihydroxyvitamin D3 (1,25D) levels had dropped below detection limits, with unchanged serum PTH, Ca, and phosphate (P) levels. Therefore, this model provides a useful tool to examine the sole effect of hypovitaminosis D, in a wide range of research settings, without confounding changes in PTH, Ca, and P.

Pseudo-enhancement does not explain the increased carotid adventitial vasa vasorum signal in diabetic patients

Department of Nephrology, Hospital Universitari Arnau de Vilanova, Rovira Roure, 80, 25198 Lleida, Spain Unitat de Deteccio i Tractament de Malalties Aterotrombotiques, Hospital Universitari Arnau de Vilanova, Rovira Roure, 80, 25198 Lleida, Spain c Institut de Recerca Biomedica de Lleida, University of Lleida, Rovira Roure, 80, 25198 Lleida, Spain Department of Endocrinology and Nutrition, Hospital Universitari Arnau de Vilanova, Rovira Roure, 80, 25198 Lleida, Spain Department of Endocrinology and Nutrition, Hospital Clinic, IDIBAPS, Villarroel, 170, 08036 Barcelona, Spain Department of Endocrinology and Nutrition, Hospital Universitari Germans Trias i Pujol, Carretera Canyet, S/N, 08916 Badalona, Spain

High Levels of Hemoglobin Promote Carotid Adventitial Vasa Vasorum Neoangiogenesis in Chronic Kidney Disease

Chronic kidney disease (CKD) patients, characterized by traditional and nontraditional risk factors, are prone to develop atheromatosis and thus cardiovascular events and mortality. The angiogenesis of the adventitial vasa vasorum (aVV) surrounding the carotid has been described as the atheromatosis initiator. Therefore, the aim of the study was to (1) evaluate if the carotid aVV in CKD patients increases in comparison to its physiological value of healthy patients; (2) explore which traditional or nontraditional risk factor including inflammation, bone and mineral metabolism, and anemia could be related to the aVV angiogenesis. CKD patients without previous cardiovascular events (44, stages 3-4; 37, stage 5D) and 65 healthy subjects were compared. The carotid aVV and the intima-media thickness (cIMT) were evaluated by ultrasound. CKD patients at stages 3-4 showed higher aVV of the right carotid artery even after adjusting for age. Importantly, a multiple linear regression model showed hemoglobin levels > 12.5 g/dL as the factor for an estimated higher aVV of the right carotid artery. In conclusion, the association of hemoglobin with higher aVV could suggest the role of high hemoglobin in the higher incidence of adverse cardiovascular outcomes in CKD patients.