6 research outputs found
Systemic cardiovascular complications in patients with long-standing diabetes mellitus: Comprehensive assessment with whole-body magnetic resonance imaging/magnetic resonance angiography.
The primary objective was to evaluate the prevalence of atherosclerotic disease, myocardial infarctions, and cerebrovascular disease in patients with long-standing diabetes using whole-body magnetic resonance imaging (WB-MRI) combined with whole-body magnetic resonance angiography (WB-MRA) and to estimate the cumulative disease burden in a new MRA-based score. Materials and Methods: The study was approved by the ethics committee and all patients gave informed written consent. Sixty-five patients with long-standing (>10 years) diabetes mellitus without acute symptoms were prospectively evaluated. The patients were clinically assessed and received WB-MRI/WB-MRA containing an examination of the brain, the heart, the arterial vessels (abdominal aorta, the supraaortic, renal, pelvic, and peripheral arteries), and the feet. Prevalence rates were calculated and compared with a healthy control group of 200 individuals after adjustment for age and sex by a logistic regression analysis using exact parameter estimates (Cochran-Mantel-Haenszel-statistics). Finally, an MRA based vessel score (sum of grades of all evaluated vessels divided by the number of vessels; grades range from 1, normal, to 6, complete occlusion) indicative of atherosclerotic disease burden was created for this study. This vessel score's association with clinical and biochemical parameters (age, sex, type of diabetes, diabetes duration, body mass index, blood pressure, smoking, coronary artery disease-status, retinopathy, serum creatinine, hemoglobin A1c test, low density lipoprotein- concentration, medication) was assessed with an age and sex adjusted analysis (generalized linear model). Results: In the diabetic patients, we found prevalence rates of 49% for peripheral artery disease, 25% for myocardial infarction, 28% for cerebrovascular disease, and 22% for neuropathic foot disease. In all vascular beds, at least 50% of the pathologies were previously unknown. Myocardial infarction (P = 0.0002), chronic ischemic cerebral lesions (P = 0.0008), and atherosclerotic disease were significantly more common in diabetic than in control subjects (internal carotid artery: P = 0.006, vertebral artery: P = 0.009, intracerebral vessels: P = 0.02, superficial femoral artery: P = 0.006, anterior tibial artery: P = 0.01, posterior tibial artery: P = 0.02, fibular artery: 0.003). The WB-MRI/WB-MRA-based score showed a significant association with age (P = 0.0008), male sex (P = 0.03), nephropathy (P = 0.006), diabetic retinopathy (P = 0.007), and coronary artery disease status (P = 0.006). Body mass index, blood pressure, hemoglobin A1c test, low density lipoprotein-cholesterol, and medications showed no significant association with the score. Conclusions: Using WB-MRI combined with WB-MRA we found a high prevalence of occult atherosclerotic disease in long-standing diabetic patients. This study shows that the true atherosclerotic burden in these patients is largely underestimated
CSI 2264:Simultaneous optical and infrared light curves of young disk-bearing stars in NGC 2264 with CoRoT and Spitzer - Evidence for multiple origins of variability
We present the Coordinated Synoptic Investigation of NGC 2264, a continuous 30 day multi-wavelength photometric monitoring campaign on more than 1000 young cluster members using 16 telescopes. The unprecedented combination of multi-wavelength, high-precision, high-cadence, and long-duration data opens a new window into the time domain behavior of young stellar objects. Here we provide an overview of the observations, focusing on results from Spitzer and CoRoT. The highlight of this work is detailed analysis of 162 classical T Tauri stars for which we can probe optical and mid-infrared flux variations to 1% amplitudes and sub-hour timescales. We present a morphological variability census and then use metrics of periodicity, stochasticity, and symmetry to statistically separate the light curves into seven distinct classes, which we suggest represent different physical processes and geometric effects. We provide distributions of the characteristic timescales and amplitudes and assess the fractional representation within each class. The largest category (>20%) are optical "dippers" with discrete fading events lasting ∼1-5 days. The degree of correlation between the optical and infrared light curves is positive but weak; notably, the independently assigned optical and infrared morphology classes tend to be different for the same object. Assessment of flux variation behavior with respect to (circum)stellar properties reveals correlations of variability parameters with Hα emission and with effective temperature. Overall, our results point to multiple origins of young star variability, including circumstellar obscuration events, hot spots on the star and/or disk, accretion bursts, and rapid structural changes in the inner disk