RESUMO
Study objectives: Debate persists as to whether obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. The purpose of this study was to compare carotid intima-media thickness (IMT), an early sign of atherosclerosis, in obese and nonobese adults with OSA before and following positive airway pressure (PAP) treatment. Methods: A total of 206 adults newly diagnosed with OSA with an apnea-hypopnea index (AHI) of 15-75 events/hour and 53 controls with AHI <10 were studied. Waist circumference was used to classify participants as obese and nonobese. Bilateral common carotid artery B-mode ultrasound was performed at baseline to assess IMT, arterial diameter, arterial-wall mass, and circumferential wall stress. Measurements were repeated in 118 participants with OSA who completed a 4-month PAP treatment and had an average daily use over that period of ≥4 hours/day. Results: No significant differences in carotid IMT, diameter, or arterial-wall mass were present at baseline between participants with OSA and controls stratified by waist circumference, after adjusting for other cardiovascular risk factors. In participants with OSA, who had adequate PAP adherence over the 4-month treatment, carotid artery diameter significantly increased (mean change [95% confidence interval] = 0.13 [0.06, 0.20] mm; p = .0004), but no significant changes in carotid IMT, arterial-wall mass, and circumferential stress were observed in obese and nonobese participants. Conclusions: Regardless of obesity status, carotid IMT is not increased in adults with moderate to severe OSA versus controls and does not change following 4 months of PAP treatment.
Assuntos
Artérias Carótidas , Espessura Intima-Media Carotídea , Obesidade/complicações , Respiração com Pressão Positiva , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/terapia , Adulto , Idoso , Aterosclerose/complicações , Aterosclerose/fisiopatologia , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Fatores de Risco , Apneia Obstrutiva do Sono/fisiopatologia , Circunferência da CinturaRESUMO
RATIONALE AND OBJECTIVES: Contrast-enhanced angiographic evaluation by magnetic resonance imaging (MRI) and computed tomography (CT) is the reference standard for assessing peripheral artery disease (PAD). However, because PAD and diabetes often coexist, the prevalence of renal insufficiency is a major challenge to contrast-based angiography. The objective of this work is to describe and demonstrate a new application of three-dimensional double-echo steady-state (3D DESS) as a noncontrast vascular MRI method for evaluating peripheral atherosclerosis at 3 Tesla (3T). MATERIALS AND METHODS: A water-selective 3D DESS pulse sequence was designed to simultaneously collect two steady-state free-precession signals (free induction decay and Echo) yielding "black blood" (BB) and "gray blood" (GB) images. For completeness Bloch equation, simulations were performed to characterize DESS signals of various tissues including blood at different velocities and to assess two healthy subjects for the purpose of pulse sequence optimization. Exploratory studies were performed as an add-on protocol to an existing study involving patients with PAD. To evaluate the method's specificity for detecting calcification, images from select patients were compared against CT angiography. RESULTS: Simulations agreed qualitatively with in vivo images supporting DESS' potential for generating distinct lumen contrast (GB vs BB). Lesions representing calcium were easily identifiable on the basis of signal void occurring on both image types and were confirmed by CT angiography. Further, BB allowed visualization of stent restenosis, and data suggest its ability to visualize acute thrombus by virtue of T2 weighting. CONCLUSION: Preliminary investigation and results suggest noncontrast 3D DESS to have the potential to improve diagnosis of PAD patients by providing detailed structural assessment of vessel-wall architecture.
Assuntos
Aterosclerose/patologia , Imageamento por Ressonância Magnética/métodos , Doença Arterial Periférica/patologia , Adulto , Feminino , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Psoriasis, especially when severe, is a risk factor for cardiometabolic disease beyond traditional risk factors. The mechanism of atherogenesis in psoriasis remains unknown. Cell membrane vesicles (ie, microparticles), released upon cell activation or apoptosis, have recently been associated with cardiometabolic disease and may play a pathogenic role. Microparticle levels, particularly from endothelial cells and platelets, are elevated in patients with cardiovascular disorders, metabolic syndrome, other inflammatory diseases, autoimmune conditions, and have been shown to be predictive of cardiovascular outcomes. METHODS AND RESULTS: Concentrations of microparticles with positive expression for any of 7 cell surface markers (Annexin V, CD3, CD31, CD41a, CD64, CD105, and CD144) were measured in blood samples from psoriasis patients (n=53) and control subjects without psoriasis (n=41). Platelet-free plasma was separated from whole blood by one-step centrifugation for microparticle analysis. Microparticles were fluorescently labeled and characterized by flow cytometry. Higher concentrations of CD105 (5.5/µL versus 2.5/µL, P<0.001), CD31 (31/µL versus 18/µL, P=0.002), CD41a (50/µL versus 22/µL, P<0.001), and CD64 (5.0/µL versus 4.1/µL, P=0.02) singly positive microparticles corresponding to endothelial cell-, platelet-, and monocyte/macrophage-derived microparticles, respectively, were found in psoriasis patients compared with controls. These differences persisted after adjustment for traditional cardiometabolic risk factors including body mass index. CONCLUSIONS: Increased microparticle concentrations, independent of cardiometabolic risk factors, in patients with psoriasis suggest that the presence of increased endothelial cell, platelet, and monocyte/macrophage activation with cell turnover may contribute to the heightened atherogenesis associated with psoriasis.
Assuntos
Plaquetas/metabolismo , Micropartículas Derivadas de Células/metabolismo , Células Endoteliais/metabolismo , Macrófagos/metabolismo , Síndrome Metabólica/etiologia , Monócitos/metabolismo , Psoríase/complicações , Adulto , Idoso , Biomarcadores/sangue , Plaquetas/patologia , Estudos de Casos e Controles , Micropartículas Derivadas de Células/patologia , Estudos Transversais , Células Endoteliais/patologia , Feminino , Citometria de Fluxo , Humanos , Macrófagos/patologia , Masculino , Síndrome Metabólica/sangue , Pessoa de Meia-Idade , Monócitos/patologia , Psoríase/sangue , Psoríase/diagnóstico , Fatores de Risco , Regulação para CimaRESUMO
OBJECTIVE: To compare lipoprotein profiles of prediabetic to normoglycemic obese adolescents. STUDY DESIGN: Cross-sectional study of 95 obese, pubertal adolescents (12-17 years), who underwent oral glucose tolerance test, lipid panel, and lipoprotein subclass particle analysis (nuclear magnetic resonance spectroscopy). Univariate and linear regression analyses compared prediabetic and normoglycemic groups. RESULTS: Of 95 obese adolescents enrolled in the study, 22.1% (n = 21) had prediabetes. They were similar to normoglycemic adolescents (n = 74) in age, race, body mass index, standard lipids, total low-density lipoprotein particles (LDL-P), and total high-density lipoprotein particles (HDL-P). However, prediabetics had higher concentrations of small LDL-P (714.0 ± 288.0 vs 537.7 ± 266.5 nmol/L, P = .01) and smaller LDL-P size (20.73 ± 0.41 vs 21.18 ± 0.65 nm, P = .003), than normoglycemic youth. Prediabetics had higher small HDL-P (18.5 ± 3.8 vs 16.6 ± 3.9 umol/L, P = .046), lower large HDL-P (4.49 ± 2.0 vs 6.32 ± 2.6 umol/L, P = .004), and smaller HDL-P size (8.73 ± 0.31 vs 9.01 ± 0.39 nm, P = .003). After adjusting for demographics, Tanner stage, and body mass index using multiple linear regression, all differences remained significant except for small HDL-P. After additional adjustment for Homeostasis Model Assessment-Insulin Resistance Index, only LDL-P size difference remained significant. CONCLUSION: Obese prediabetic adolescents have a significantly more atherogenic lipoprotein profile compared with obese normoglycemic peers. Prediabetic adolescents may benefit from more aggressive interventions to decrease future cardiovascular risk.