Frequent extreme cold exposure and brown fat and cold-induced thermogenesis: A study in a monozygotic twin

INTRODUCTION: Mild cold acclimation is known to increase brown adipose (BAT) activity and cold-induced thermogenesis (CIT) in humans. We here effect of a lifestyle with frequent exposure to extreme cold on BAT and Dutch man known as 'the Iceman', who has multiple world records in extreme cold challenges. Furthermore, his monozygotic twin brother who 'normal' sedentary lifestyle without extreme cold exposures was METHODS: The Iceman (subject A) and his brother (subject B) were studied mild cold (13 degrees C) and thermoneutral conditions (31 degrees C). Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect addition, body temperatures, cardiovascular parameters, skin perfusion, thermal sensation and comfort were measured. Finally, we determined for uncoupling protein-1 and beta3-adrenergic receptor. RESULTS: comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal), within previously observed in young adult men. They were genotyped with the for uncoupling protein-1 (G/G). CIT was relatively high (A: 40.1% and B: but unlike during our previous cold exposure tests in young adult men, subjects practiced a g-Tummo like breathing technique, which involves respiratory muscle activity. This was confirmed by high [18F]FDG-uptake respiratory muscle. CONCLUSION: No significant differences were found two subjects, indicating that a lifestyle with frequent exposures to does not seem to affect BAT activity and CIT. In both subjects, BAT was higher compared to earlier observations, whereas CIT was very high, that g-Tummo like breathing during cold exposure may cause additional production by vigorous isometric respiratory muscle contraction. The be interpreted with caution given the low subject number and the fact participants practised the g-Tummo like breathing technique

Vagus nerve stimulation increases energy expenditure: relation to brown adipose tissue activity

BackgroundHuman brown adipose tissue (BAT) activity is inversely related to obesity and positively related to energy expenditure. BAT is highly innervated and it is suggested the vagus nerve mediates peripheral signals to the central nervous system, there connecting to sympathetic nerves that innervate BAT. Vagus nerve stimulation (VNS) is used for refractory epilepsy, but is also reported to generate weight loss. We hypothesize VNS increases energy expenditure by activating BAT.Methods and findingsFifteen patients with stable vns therapy (age: 45 ± 10 yrs; body mass index; 25.2 ± 3.5 kg/m(2)) were included between January 2011 and June 2012. Ten subjects were measured twice, once with active and once with inactivated VNS. Five other subjects were measured twice, once with active VNS at room temperature and once with active VNS under cold exposure in order to determine maximal cold-induced BAT activity. BAT activity was assessed by 18-Fluoro-Deoxy-Glucose-Positron-Emission-Tomography-and-Computed-Tomography. Basal metabolic rate (BMR) was significantly higher when VNS was turned on (mean change; +2.2%). Mean BAT activity was not significantly different between active VNS and inactive VNS (BAT SUV(Mean); 0.55 ± 0.25 versus 0.67 ± 0.46, P = 0.619). However, the change in energy expenditure upon VNS intervention (On-Off) was significantly correlated to the change in BAT activity (r = 0.935, PConclusionsVNS significantly increases energy expenditure. The observed change in energy expenditure was significantly related to the change in BAT activity. This suggests a role for BAT in the VNS increase in energy expenditure. Chronic VNS may have a beneficial effect on the human energy balance that has potential application for weight management therapy.Trial registrationThe study was registered in the Clinical Trial Register under the ClinicalTrials.gov Identifier NCT01491282

Contemporary management of patients with atrial fibrillation in the Netherlands and Belgium: a report from the EORP-AF long-term general registry

Background: Contemporary data regarding the characteristics, treatment and outcomes of patients with atrial fibrillation (AF) are needed. We aimed to assess these data and guideline adherence in the EURObservational Research Programme on Atrial Fibrillation (EORP-AF) long-term general registry. Methods: We analysed 967 patients from the EORP-AF long-term general registry included in the Netherlands and Belgium from 2013 to 2016. Baseline and 1\u2011year follow-up data were gathered. Results: At baseline, 887 patients (92%) received anticoagulant treatment. In 88 (10%) of these patients, no indication for chronic anticoagulant treatment was present. A rhythm intervention was performed or planned in 52 of these patients, meaning that the remaining 36 (41%) were anticoagulated without indication. Forty patients were not anticoagulated, even though they had an indication for chronic anticoagulation. Additionally, 63 of the 371 patients (17%) treated with a non-vitamin K antagonist oral anticoagulant (NOAC) were incorrectly dosed. In total, 50 patients (5%) were overtreated and 89 patients (9%) were undertreated. However, the occurrence of major adverse cardiac and cerebrovascular events (MACCE) was still low with 4.2% (37 patients). Conclusions: Overtreatment and undertreatment with anticoagulants are still observable in 14% of this contemporary, West-European AF population. Still, MACCE occurred in only 4% of the patients after 1 year of follow-up