Our findings indicate that obesity is associated with smaller subcortical gray matter volumes and higher coherence but lower magnitude of white matter microstructure. These results indicate the need for future studies on the biologic basis of alterations in brain structure in obesity. Background Obesity has been associated with increased risk of accelerated cognitive decline and dementia, which suggests underlying neurobiological changes. Purpose To investigate the associations between obesity and brain structure (overall and regional brain volumes, and white matter microstructure) assessed at MRI in a sample of the general population. Materials and Methods Between March 2014 and January 2018, 12 087 participants (52.8% women [6381 of 12 087]; mean age, 62 years; age range, 45–76 years) in the prospective observational UK Biobank study underwent 3.0-T multiparametric (ie, three-dimensional T1-weighted diffusion tensor imaging [DTI]) brain imaging. Percentage of total body fat (TBF) was assessed by body impedance. Volumetric measures included brain volume, gray matter volume, white matter volume, volumes of subcortical gray matter structures, and regional cortical volumes. Global and tract-specific microstructure was assessed by fractional anisotropy (FA) and mean diffusivity (MD) by us...
Background: Liraglutide is an antidiabetic agent with cardioprotective effect. The purpose of this study is to test efficacy of liraglutide to improve diabetic cardiomyopathy in patients with diabetes mellitus type 2 (DM2) without cardiovascular disease. Methods: Patients with DM2 were randomly assigned to receive liraglutide 1.8 mg/day or placebo in this double-blind trial of 26 weeks. Primary outcome measures were LV diastolic function (early (E) and late (A) transmitral peak flow rate, E/A ratio, early deceleration peak (Edec), early peak mitral annular septal tissue velocity (Ea) and estimated LV filling pressure (E/Ea), and systolic function (stroke volume, ejection fraction, cardiac output, cardiac index and peak ejection rate) assessed with CMR. Intention-to-treat analysis of between-group differences was performed using ANCOVA. Mean estimated treatment differences (95% confidence intervals) are reported. Results: 23 patients were randomized to liraglutide and 26 to placebo. As compared with placebo, liraglutide significantly reduced E (− 56 mL/s (− 91 to − 21)), E/A ratio (− 0.17 (− 0.27 to − 0.06)), Edec (− 0.9 mL/s2 * 10−3 (− 1.3 to − 0.2)) and E/Ea (− 1.8 (− 3.0 to − 0.6)), without affecting A (3 mL/s (− 35 to 41)) and Ea (0.4 cm/s (− 0.9 to 1.4)). Liraglutide reduced stroke volume (− 9 mL (− 16 to − 2)) and ejection fraction (− 3% (− 6 to − 0.1)), but did not change cardiac output (− 0.4 L/min (− 0.9 to 0.2)), cardiac index (− 0.1 L/min/m2 (− 0.4 to 0.1)) and peak ejection rate (− 46 mL/s (− 95 to 3)). Conclusions: Liraglutide reduced early LV diastolic filling and LV filling pressure, thereby unloading the left ventricle. LV systolic function reduced and remained within normal range. Future studies are needed to investigate if liraglutide-induced left ventricular unloading slows progression of diabetic cardiomyopathy into symptomatic stages. Trial registration ClinicalTrials.gov: NCT01761318.
Institutional review board approval and informed consent were obtained. The purpose of the study was to prospectively compare spectral resolution and reproducibility of hydrogen 1 (1H) magnetic resonance (MR) spectroscopy, with and without respiratory motion compensation based on navigator echoes, in the assessment of myocardial triglyceride content in the human heart. In 20 volunteers (14 men, six women; mean age ± standard error, 31 years ± 2.8 [range, 19–60 years]; body mass index, 19–30 kg/m2) without history of cardiovascular disease, 1H MR spectroscopy of the myocardium was performed at rest, with and without respiratory motion compensation. Unsuppressed water signal linewidth changed from 11.9 Hz to 10.7 Hz (P < .001) with the use of the navigator, which indicated better spectral resolution. The navigator improved the intraclass correlation coefficient for the assessment of myocardial triglyceride content from 0.32 to 0.81. Therefore, the authors believe that respiratory motion correction is essent...
Aims/hypothesis: We hypothesised that the insulin-sensitising effect of physical activity depends on the timing of the activity. Here, we examined cross-sectional associations of breaks in sedentary time and timing of physical activity with liver fat content and insulin resistance in a Dutch cohort. Methods: In 775 participants of the Netherlands Epidemiology of Obesity (NEO) study, we assessed sedentary time, breaks in sedentary time and different intensities of physical activity using activity sensors, and liver fat content by magnetic resonance spectroscopy (n=256). Participants were categorised as being most active in the morning (06:00–12:00 hours), afternoon (12:00–18:00 hours) or evening (18:00–00:00 hours) or as engaging in moderate-to-vigorous-physical activity (MVPA) evenly distributed throughout the day. Most active in a certain time block was defined as spending the majority (%) of total daily MVPA in that block. We examined associations between sedentary time, breaks and timing of MVPA with liver fat content and HOMA-IR using linear regression analyses, adjusted for demographic and lifestyle factors including total body fat. Associations of timing of MVPA were additionally adjusted for total MVPA. Results: The participants (42% men) had a mean (SD) age of 56 (4) years and a mean (SD) BMI of 26.2 (4.1) kg/m2. Total sedentary time was not associated with liver fat content or insulin resistance, whereas the amount of breaks in sedentary time was associated with higher liver fat content. Total MVPA (−5%/h [95% CI −10%/h, 0%/h]) and timing of MVPA were associated with reduced insulin resistance but not with liver fat content. Compared with participants who had an even distribution of MVPA throughout the day, insulin resistance was similar (−3% [95% CI −25%, 16%]) in those most active in morning, whereas it was reduced in participants who were most active in the afternoon (−18% [95% CI −33%, −2%]) or evening (−25% [95% CI −49%, −4%]). Conclusions/interpretation: The number of daily breaks in sedentary time was not associated with lower liver fat content or reduced insulin resistance. Moderate-to-vigorous activity in the afternoon or evening was associated with a reduction of up to 25% in insulin resistance. Further studies should assess whether timing of physical activity is also important for the occurrence of type 2 diabetes. Graphical