Type 2 diabetes en hart- en vaatziekten (‘cardiometabole ziekten’) leiden wereldwijd tot veel sterfte. Vergeleken met mensen van West-Europese afkomst hebben Zuid-Aziaten een verhoogd risico op... Show moreType 2 diabetes en hart- en vaatziekten (‘cardiometabole ziekten’) leiden wereldwijd tot veel sterfte. Vergeleken met mensen van West-Europese afkomst hebben Zuid-Aziaten een verhoogd risico op deze ziekten. Dit komt gedeeltelijk door hun ongunstige lichaamssamenstelling met veel buikvet en vetopslag in organen zoals spieren en lever, wat hun werking verstoort. Het verminderen van overgewicht verlaagt het risico op type 2 diabetes en hart- en vaatziekten. Verminderen van voedselinname en verhogen van het energieverbruik kan hieraan bijdragen. Een veelbelovende aanpak om het energieverbruik te verhogen, is het stimuleren van vet- en suikerverbranding door lichaamseigen bruin vetweefsel. In dit proefschrift onderzochten wij eerst mechanismen die bijdragen aan cardiometabole ziekten in Zuid-Aziaten. Wij observeerden verminderde Wnt signaaltransductie in wit vet van Zuid-Aziaten, wat samenhing met minder insulinegevoeligheid in dit weefsel. Ook vonden wij een andere samenstelling van LDL-deeltjes in Zuid-Aziaten, wat samenhing met een verhoogde neiging van deze deeltjes om samen te klonteren. Daarna onderzochten wij de effectiviteit van geneesmiddelen om bruin vet activiteit te verhogen en de cardiometabole gezondheid te verbeteren. Wij lieten zien dat stimuleren van de beta-adrenerge receptor de stofwisseling verhoogt en vetverbranding door bruin vet stimuleert, echter niet méer dan koudeblootstelling. Ook vonden wij dat GLP-1 receptoragonisme de suikeropname door bruin vet stimuleert, wat mogelijk bijdraagt aan een gunstig effect op het lichaamsgewicht en suiker- en vetstofwisseling. Deze studies hebben bijgedragen aan kennis over risicofactoren voor cardiometabole ziekten en de ontwikkeling van nieuwe therapeutische strategieën om deze ziekten tegen te gaan, vooral in Zuid-Aziaten. Show less
Hoekstra, M.; Ouweneel, A.B.; Price, J.; Geest, R. van der; Sluis, R.J. van der; Geerling, J.J.; ... ; Eck, M. van 2020
Scavenger receptor BI (SR-BI) has been suggested to modulate adipocyte function. To uncover the potential relevance of SR-BI for the development of obesity and associated metabolic complications,... Show moreScavenger receptor BI (SR-BI) has been suggested to modulate adipocyte function. To uncover the potential relevance of SR-BI for the development of obesity and associated metabolic complications, we compared the metabolic phenotype of wild-type and SR-BI deficient mice fed an obesogenic diet enriched in fat. Both male and female SR-BI knockout mice gained significantly more weight as compared to their wild-type counterparts in response to 12 weeks high fat diet feeding (1.5-fold; P < .01 for genotype). Plasma free cholesterol levels were ~2-fold higher (P < .001) in SR-BI knockout mice of both genders, whilst plasma cholesteryl ester and triglyceride concentrations were only significantly elevated in males. Strikingly, the exacerbated obesity in SR-BI knockout mice was paralleled by a better glucose handling. In contrast, only SR-BI knockout mice developed atherosclerotic lesions in the aortic root, with a higher predisposition in females. Biochemical and histological studies in male mice revealed that SR-BI deficiency was associated with a reduced hepatic steatosis degree as evident from the 29% lower (P < .05) liver triglyceride levels. Relative mRNA expression levels of the glucose uptake transporter GLUT4 were increased (+47%; P < .05), whilst expression levels of the metabolic PPARgamma target genes CD36, HSL, ADIPOQ and ATGL were reduced 39%-58% (P < .01) in the context of unchanged PPARgamma expression levels in SR-BI knockout gonadal white adipose tissue. In conclusion, we have shown that SR-BI deficiency is associated with a decrease in adipocyte PPARgamma activity and a concomitant uncoupling of obesity development from hepatic steatosis and glucose intolerance development in high fat diet-fed mice. Show less
The aim of this thesis was to unravel a selection of a multitude of potential causal pathways that may underlie the association between excess body fat and cardiovascular disease, such as... Show moreThe aim of this thesis was to unravel a selection of a multitude of potential causal pathways that may underlie the association between excess body fat and cardiovascular disease, such as adipokines, inflammation, HDL-cholesterol and postprandial triglyceride response, and cholesteryl ester transfer protein (CETP). We showed that hs-CRP and GlycA as measures of inflammation, adiponectin, and leptin are not associated with clinical and subclinical cardiovascular disease in the general population. However, all may be relevant markers of disease risk. Also, postprandial triglyceride excursions, genetically-determined CETP and HDL-cholesterol, while not related with subclinical atherosclerosis in the general population, may be interesting targets to pursue in women and men separately, and in subgroups of individuals at high-cardiovascular risk. Show less
Heparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. While the role of heparanase in sustaining the pathology of autoimmune... Show moreHeparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. While the role of heparanase in sustaining the pathology of autoimmune diabetes is well documented, its association with metabolic syndrome/type 2 diabetes attracted less attention. Our research was undertaken to elucidate the significance of heparanase in impaired glucose metabolism in metabolic syndrome and early type 2 diabetes. Here, we report that heparanase exerts opposite effects in insulin-producing (i.e., islets) vs. insulin-target (i.e., skeletal muscle) compartments, sustaining or hampering proper regulation of glucose homeostasis depending on the site of action. We observed that the enzyme promotes macrophage infiltration into islets in a murine model of metabolic syndrome, and fosters beta-cell-damaging properties of macrophages activated in vitro by components of diabetogenic/obese milieu (i.e., fatty acids). On the other hand, in skeletal muscle (prototypic insulin-target tissue), heparanase is essential to ensure insulin sensitivity. Thus, despite a deleterious effect of heparanase on macrophage infiltration in islets, the enzyme appears to have beneficial role in glucose homeostasis in metabolic syndrome. The dichotomic action of the enzyme in the maintenance of glycemic control should be taken into account when considering heparanase-targeting strategies for the treatment of diabetes. Show less
In this thesis, we focussed on the management of obese patients with asthma. Based on the available knowledge about the obesity and asthma relationship, and the effects of different weight loss... Show moreIn this thesis, we focussed on the management of obese patients with asthma. Based on the available knowledge about the obesity and asthma relationship, and the effects of different weight loss interventions in obese asthmatics, we defined the following aimsfor this thesis:1. To gain insight in the effects of exercise training in obese asthmatics and to determine the feasibility and effects of high intensity training in obese subjects2. To design a pulmonary rehabilitation program for obese patients with suboptimalcontrolled asthma and to determine the effectiveness of this program in a randomized controlled trial3. To improve our knowledge on the pathophysiology of obesity related asthma4. To gain insight in the risks and long-term effects of bariatric surgery in morbidlyobese subjects with asthma. Show less
Objective: To investigate the association between body mass index (BMI) and oral anticoagulant (OAC) prescription in atrial fibrillation (AF).Methods: Patients with newly diagnosed non-valvular AF ... Show moreObjective: To investigate the association between body mass index (BMI) and oral anticoagulant (OAC) prescription in atrial fibrillation (AF).Methods: Patients with newly diagnosed non-valvular AF (< 3 months) with >= 1 stroke risk factors enrolled in the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) in Asia, Europe and North America were evaluated.Results: The cohort (n = 13,793) comprised patients from all BMI categories (kg/m(2)): 1.4% were underweight (<18.5), 27.3% had a normal BMI (18.5 to <25), 37.9% were overweight (25 to <30), 19.3% were moderately obese (30 to < 35), and 12.7% were morbidly obese (>= 35). The highest proportion of Asians had a BMI of 18.5 to <25 kg/m(2), while the highest proportion of patients from Europe and North America were overweight and a substantial proportion of North Americans morbidly obese. In the multivariable analysis, the probability ratio of non-prescription of OAC, as compared to normal BMI, decreased for overweight (RR = 0.907), moderately obese (RR = 0.802) and severe very severe obese patients (RR = 0.659). Moreover, the probability ratio of non-prescription of OACs was increased in the Asia or North America regions, as compared with Europe, in patients aged <65 years or female patients, as well as in patients with prior bleeding or vascular disease.Conclusions: The distribution of BMI differed among the continents. An increased BMI was associated with a lower probability of non-prescription of OACs, as compared with a normal BMI. The probability of non-prescription of OACs was increased in the Asia or North America regions, as compared with Europe. Show less
Over the past decades, the number of individuals with type 2 diabetes has been growing worldwide. Type 2 diabetes is a major health concern, as it is related to several conditions, including heart... Show moreOver the past decades, the number of individuals with type 2 diabetes has been growing worldwide. Type 2 diabetes is a major health concern, as it is related to several conditions, including heart failure and coronary artery disease. Despite remarkable advances in cardiovascular prevention and treatment, heart disease remains a common cause of death and an important contributor to health loss. The aim of this thesis was to characterize cardiovascular remodeling associated with metabolic disturbances, using a variety of magnetic resonance techniques. This thesis demonstrates that reduced diastolic function is a common characteristic of myocardial remodeling in type 2 diabetes and obesity, but also a potential marker for the detection of patients at increased cardiovascular risk after hematopoietic stem cell transplantation and possibly a contributing factor in the pathogenesis of ventricular arrhythmia after myocardial infarction. Also, in this thesis, it was shown that the evaluation of visceral adiposity and myocardial triglyceride content may help to identify distinct cardiometabolic phenotypes and to better understand the cardiometabolic actions of the glucagon-like peptide 1 receptor agonist liraglutide. With the emergence of non-contrast cardiovascular protocols, magnetic resonance techniques may be increasingly used for cardiometabolic phenotyping in population-based cohorts as well as clinical studies. Show less
The aim of this thesis was to evaluate quantitative MRI techniques in reno-cardiovascular health, and to study the links between obesity and reno-cardiovascular health using quantitative MRI... Show moreThe aim of this thesis was to evaluate quantitative MRI techniques in reno-cardiovascular health, and to study the links between obesity and reno-cardiovascular health using quantitative MRI metrics. Furthermore, we aimed to address novel insights on the safety of contrast media with regard to the use of gadolinium. The general introduction (Chapter 1) of this thesis introduces the concept of quantitative MRI, its application in epidemiological research, reno-cardiovascular health, and in obesity. In addition, the general introduction addresses the safety of gadolinium as an MRI contrast agent. Following the general introduction a review of the clinical application and technical considerations of quantitative MRI using T1 and T2(*) mapping in cardiac and renal imaging was provided in Chapter 2. Part 1 of this thesis focused on the reproducibility and clinical validity of T1 mapping and proton magnetic resonance spectroscopy (1H-MRS) in renal imaging. Part 2, described different studies evaluating the association between obesity and reno-cardiovascular function which was analyzed in population-based imaging studies using different quantitative MRI metrics. Part 3, provides an overview of the safety profile of gadolinium containing contrast agents, and reflection on the recent EMA recommendations. Show less
Velde, L.A. van der; Nyns, C.J.; Engel, M.D.; Neter, J.E.; Meer, I.M. van der; Numans, M.E.; Kiefte-de Jong, J.C. 2020
BackgroundFood insecurity is related to risk of adverse health outcomes such as obesity, but the explanatory factors underlying this association are still unclear. This study aimed to assess the... Show moreBackgroundFood insecurity is related to risk of adverse health outcomes such as obesity, but the explanatory factors underlying this association are still unclear. This study aimed to assess the association between food insecurity and obesity, and to explore potential mediation by sociodemographic and lifestyle factors.MethodsThis cross-sectional study was conducted among 250 participants in a deprived urban area in the Netherlands. Data on sociodemographic and lifestyle factors, food insecurity status and diet quality were collected using questionnaires. Diet quality was determined based on current national dietary guidelines. BMI was calculated from self-reported height and weight. Regression analyses were performed to explore the association between food insecurity and BMI status. Mediation analyses were performed to estimate the total-, direct-, and indirect effect and proportion of total effect mediated of the food insecurity-obesity association.ResultsThe overall prevalence of food insecurity was 26%. Food insecurity was associated with obesity (OR=2.49, 95%CI=1.16, 5.33), but not with overweight (OR=1.15, 95%CI=0.54, 2.45) in the unadjusted model. The food insecurity-obesity association was partially mediated by living situation (proportion mediated: 15.4%), diet quality (-18.6%), and smoking status (-15.8%) after adjustment for other covariates.ConclusionsThe findings of this study suggest an association between food insecurity and obesity. Living situation, diet quality and smoking status explained part, but not all, of the total association between food insecurity and obesity. Future longitudinal studies are warranted to examine the temporal order of the food insecurity-obesity association and potential mediators in this relationship. In addition, food insecurity and its potential consequences need to be taken into account in obesity prevention programs and policies. Show less
The prevalence of obesity is increasing worldwide. In particular abdominal obesity is a well-established risk factor for cardiometabolic diseases. The excess risk of abdominal obesity is due to fat... Show moreThe prevalence of obesity is increasing worldwide. In particular abdominal obesity is a well-established risk factor for cardiometabolic diseases. The excess risk of abdominal obesity is due to fat in the visceral area and in and around the organs (ectopic fat), such as in the liver. The main aim of this thesis was therefore to study whether lifestyle can reduce the amount of visceral fat and liver fat.Firstly, in a systematic review and meta-analysis of randomized controlled trials, we concluded that a diet high in proteins decreases liver fat compared with a diet high in carbohydrates. A diet high in fat did not lead to changes in liver fat compared with a diet high in carbohydrates. Within fat types, saturated fat leads to more liver fat accumulation than unsaturated fat. Secondly, we studied diet at multiple levels in the Netherlands Epidemiology of Obesity study, which is a population based cohort study of middle-aged men and women with directly assessed measured of adiposity. When studying food groups rather than nutrients, we observed that consumption of sweet snacks are positively associated with liver fat content, also after taking into account total body fat. Likewise, consumption of fruit and vegetables and plant-based fats and oils was associated with less visceral fat. A better adherence to the current Dutch dietary guidelines, as indicated by a higher score on the 15-component Dutch Healthy Diet Index, was associated with less total body fat, less visceral fat and liver fat. The associations with visceral fat and liver fat remained present after taking into account total body fat, indicating that the associations are indeed specific for visceral and liver fat rather than merely representing associations with overall adiposity. Associations were not driven by one component in particular, indicating the importance of an overall healthy diet. When we studied alcohol intake separately, each additional serving of alcoholic beverages per day was also associated with more liver fat. Moreover, replacing one alcoholic serving with one non-alcoholic serving was associated with less liver fat. Replacing the same amount of calories of alcoholic beverages with sugar sweetened beverages was equally associated with liver fat, whereas replacement with milk was associated with less liver fat. Lastly, we observed that objectively measured sedentary time was associated with more total body fat, visceral fat and liver fat. Replacing 30 minutes of sedentary time per day with moderate to vigorous physical activity, but not light physical activity was associated with less total body fat, visceral fat and liver fat. These associations with visceral fat and liver fat disappeared after additional adjustment for total body fat, indicating that there is no extra effect on visceral fat and liver fat beyond effects via total body fat.Results described in this thesis hint towards the importance of considering diet as a whole, instead of separate components, which is in line with the current dietary guidelines. Sedentary behaviour should be replaced with moderate to vigorous physical activity rather than light physical activity. Alcohol should not be replaced with sugar sweetened beverages, but rather with milk, coffee or tea. Show less
Aims We aimed to evaluate the associations of body fat distribution with cardiovascular function and geometry in the middle-aged general population.Methods and results Four thousand five hundred... Show moreAims We aimed to evaluate the associations of body fat distribution with cardiovascular function and geometry in the middle-aged general population.Methods and results Four thousand five hundred and ninety participants of the UK Biobank (54% female, mean age 61.1 +/- 7.2 years) underwent cardiac magnetic resonance for assessment of left ventricular (LV) parameters [end-diastolic volume (EDV), ejection fraction (EF), cardiac output (CO), and index (CI)] and magnetic resonance imaging for body composition analysis [subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT)]. Body fat percentage (BF%) was assessed by bioetectrical impedance. Linear regressions were performed to assess the impact of visceral (VAT) and general (SAT and BF%) obesity on cardiac function and geometry. Visceral obesity was associated with a smaller EDV [VAT: beta -1.74 (-1.15 to -2.33)1, lower EF NAT: beta -0.24 (-0.12 to -0.35), SAT: beta 0.02 (-0.04 to 0.08), and BF%: beta 0.02 (-0.02 to 0.06)] and the strongest negative association with CI [VAT: beta -0.05 (-0.06 to -0.04), SAT: beta -0.02 (-0.03 to -0.01), and BF% beta -0.01 (-0.013 to -0.007)]. In contrast, general obesity was associated with a larger EDV [SAT: beta 1.01 (0.72-1.30), BF%: beta 0.37 (0.23-0.51)] and a higher CO [SAT: beta 0.06 (0.05-0.07), BF%: beta 0.02 (0.01-0.03)]. In the gender-specific analysis, only men had a significant association between VAT and EF [beta -0.35 (-0.19 to -0.51)].Conclusions Visceral obesity was associated with a smaller LV EDV and subclinical lower LV systolic function in men, suggesting that visceral obesity might play a more important role compared to general obesity in LV remodelling. Show less
Hoekstra, M.; Sluis, R.J. van der; Hildebrand, R.B.; Lammers, B.; Zhao, Y.; Praticò, D.; ... ; Eck, M. van 2020
C]cholesteryl oleate after intravenous VLDL-like particle injection.\nWe have shown that disruption of PLTP-mediated HDL maturation reduces SR-BI deficiency-driven atherosclerosis susceptibility in... Show moreC]cholesteryl oleate after intravenous VLDL-like particle injection.\nWe have shown that disruption of PLTP-mediated HDL maturation reduces SR-BI deficiency-driven atherosclerosis susceptibility in mice despite the induction of proatherogenic metabolic complications in the double knockout mice.\nOBJECTIVE\nCONCLUSIONS Show less
Kroon, F.P.B.; Veenbrink, A.I.; Mutsert, R. de; Visser, A.W.; Dijk, K.W. van; Cessie, S. le; ... ; Kloppenburg, M. 2019
Background & aims: Obesity is a well-established risk factor of vitamin D deficiency. However, it is unclear which fat deposit is most strongly related to serum 25-hydroxyvitamin D (25(OH)D)... Show moreBackground & aims: Obesity is a well-established risk factor of vitamin D deficiency. However, it is unclear which fat deposit is most strongly related to serum 25-hydroxyvitamin D (25(OH)D) concentrations. Our aim was to distinguish the specific contributions of total body fat (TBF), abdominal subcutaneous adipose tissue (aSAT), visceral adipose tissue (VAT) and hepatic fat on 25(OH)D concentrations.Methods: We performed a cross-sectional analysis of the Netherlands Epidemiology of Obesity study, a population-based cohort study. We used linear regression analyses to examine associations of TBF, aSAT, VAT (n = 2441) and hepatic fat (n = 1980) with 25(OH)D concentrations. Standardized values were used to compare the different fat deposits.Results: Mean (SD) age and 25(OH)D concentrations of the study population was 56 (6) years and 70.8 (24.2) nmol/L, respectively. TBF was inversely associated with 25(OH)D concentrations in women, but not in men. One percent higher TBF was associated with 0.40 nmol/L (95%CI: -0.67 to -0.13) lower 25(OH)D. aSAT was not associated with 25(OH)D concentrations. One cm 2 higher VAT was associated with 0.05 nmol/L (-0.09 to -0.02) lower 25(OH)D in men, and 0.06 nmol/L (-0.10 to -0.01) lower 25(OH)D in women. Hepatic fat was only associated with 25(OH)D in men. A tenfold increase in hepatic fat was associated with 6.21 nmol/L (-10.70 to -1.73) lower 25(OH)D. Regressions with standardized values showed VAT was most strongly related to 25(OH)D.Conclusions: In women, TBF and VAT were inversely related to 25(OH)D concentrations. In men, VAT and hepatic fat were inversely related to 25(OH)D concentrations. In both groups, VAT was most strongly associated with 25(OH)D concentrations. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. Show less
Aims/hypothesis Circulating succinate and 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) were recently shown to promote brown adipocyte thermogenesis and protect against metabolic disorders in... Show moreAims/hypothesis Circulating succinate and 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) were recently shown to promote brown adipocyte thermogenesis and protect against metabolic disorders in rodents. This study aimed to evaluate the associations between plasma levels of these metabolites and adiposity and metabolic profile in humans. Methods Fasting plasma succinate and 12,13-diHOME levels were quantified using ultra HPLC-tandem MS in 2248 individuals (50% female, mean age 41.3 +/- 5.9 years, mean BMI 26.1 +/- 4.6 kg/m(2)) in addition to fasting plasma biochemistry. Total and regional adiposity were assessed with dual-energy x-ray absorptiometry. An age- and sex-adjusted linear regression model was used to determine the associations between succinate and 12,13-diHOME levels and body composition and metabolic profile. Two-sample Mendelian randomisation was used to assess the associations between genetically determined BMI and metabolic traits with circulating plasma succinate and 12,13-diHOME. Results A one-SD higher plasma succinate and 12,13-diHOME concentration was associated with a 0.15 SD (95% CI 0.28, 0.03) and 0.08 SD (0.15, 0.01) lower total fat mass respectively. Additionally, a one-SD higher plasma 12,13-diHOME level was associated with a 0.09 SD (0.16, 0.02) lower fasting plasma insulin and 0.10 SD (0.17, 0.04) lower plasma triacylglycerol. In Mendelian randomisation analyses, genetically determined higher BMI, fasting hyperinsulinaemia and elevated lipid levels were not associated with changes in either plasma succinate or plasma 12,13-diHOME concentrations. No indications of bias due to directional pleiotropy were detected in the Mendelian randomisation analyses. Conclusions/interpretation Our findings tentatively suggest that plasma succinate and 12,13-diHOME may play a role in the regulation of energy metabolism and brown adipose tissue activation in humans. Further studies encompassing direct assessment of brown adipose tissue activity and dietary supplementation are necessary to investigate the potential beneficial effects of these metabolites on systemic metabolism. Show less
Introduction We investigated improvement of electrocardiographic LVH detection by adding measures of adiposity and/or novel electrocardiographic measures. Left ventricular hypertrophy (LVH) is an... Show moreIntroduction We investigated improvement of electrocardiographic LVH detection by adding measures of adiposity and/or novel electrocardiographic measures. Left ventricular hypertrophy (LVH) is an important risk factor for adverse cardiovascular outcomes. Improvement of electrocardiographic criteria for LVH is desirable, since electrocardiography is widely used. Methods We included 1091 participants of the Netherlands Epidemiology of Obesity Study (NEO) who underwent cardiac magnetic resonance imaging (MRI). Performance of Sokolow-Lyon and Cornell voltage and product criteria was assessed. Stepwise regression analysis was performed with each conventional electrocardiographic criterion and age, sex, body mass index (BMI), waist circumference, and waist:hip ratio (p-entry < 0.05, p-removal > 0.10). T-wave abnormalities or the spatial QRS-T angle (SA) were added to the improved models. Results The study population had a mean (SD) age of 56 (6) years, BMI of 26.1 (4.0) kg/m(2) and 46% were men. MRI-LVH was present in 10% of participants. The c-statistic for Sokolow-Lyon voltage was 0.58, R-2 was 0.02 and sensitivity at 90% specificity was 16%, for Sokolow-Lyon product this was 0.62, 0.02, and 21%, for Cornell voltage 0.65, 0.04, and 28% and for Cornell product 0.67, 0.04, and 25%. Best performing models were obtained by addition of both BMI and SA (Sokolow-Lyon voltage: c-statistic 0.74, R-2 0.11, sensitivity of 41% at 90% specificity; Sokolow-Lyon product: 0.75, 0.12, 42%; Cornell voltage: c-statistic 0.70, R-2 0.08, sensitivity of 38% at 90% specificity; Cornell product: c-statistic 0.72, R-2 0.08, sensitivity of 44% at 90% specificity). Conclusions Electrocardiographic detection of LVH improved by adding BMI and SA to a model with conventional electrocardiographic criteria. This approach would require little extra effort and application in clinical practice is feasible. However, results should first be replicated in high-risk populations. Show less
Background & aims: Since the discovery of active brown adipose tissue in human adults, non-shivering cold-induced thermogenesis (CIT) has been regarded as a promising tool to combat obesity.... Show moreBackground & aims: Since the discovery of active brown adipose tissue in human adults, non-shivering cold-induced thermogenesis (CIT) has been regarded as a promising tool to combat obesity. However, there is a lack of consensus regarding the method of choice to analyze indirect calorimetry data from a CIT study. We analyzed the impact of methods for data selection and methods for data analysis on measures of cold-induced energy expenditure (EE) and nutrient oxidation rates.Methods: Forty-four young healthy adults (22.1 +/- 2.1 years old, 25.6 +/- 5.2 kg/m(2), 29 women) participated in the study. Resting metabolic rate (RMR), cold-induced thermogenesis (CIT), and cold-induced nutrient oxidation rates were estimated by indirect calorimetry under fasting conditions during 1 h of cold exposure combining air conditioning (19.5-20 degrees C) and a water perfused cooling vest set at a temperature of 4 degrees C above the individual shivering threshold. We applied three methods for data selection: (i) time intervals every 5 min (5min-TI), (ii) the most stable 5-min period of every forth part of the cold exposure (5min-SS-4P), and (iii) the most stable 5-min period of every half part of the cold exposure (5min-SS-2P). Lately we applied two methods for data analysis: (i) area under the curve as a percentage of the baseline RMR (AUC) and; (ii) the difference between EE at the end of the cold exposure and baseline RMR (Last-RMR).Results: Mean overall CIT estimation ranged from 11.6 +/- 10.0 to 20.1 +/- 17.2 %RMR depending on the methods for data selection and analysis used. Regarding methods for data selection, 5min-SS-2P did not allow to observe physiologically relevant phenomena (e.g. metabolic shift in fuel oxidation; P = 0.547) due to a lack of resolution. The 5min-TI and 5min-SS-4P methods for data selection seemed to be accurate enough to observe physiologically relevant phenomena (all P < 0.014), but not comparable for estimating over-all CIT and cold-induced nutrient oxidation rates (P < 0.01). Regarding methods for data analysis, the AUC seemed to be less affected for data artefacts and to be more representative in participants with a non-stable energy expenditure during cold exposure.Conclusions: The methods for data selection and analysis can have a profound impact on CIT and cold-induced nutrient oxidation rates estimations, and therefore, it is mandatory to unify it across scientific community to allow inter-study comparisons. Based on our findings, 5min-TI should be considered the method of choice to study dynamics (i.e. changes across time) of CIT and cold-induced nutrient oxidation rates, while 5min-SS-4P and AUC should be the method of choice when computing CIT and cold-induced nutrient oxidation rates as a single value. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. Show less
Turk, Y.; Sin, H.K.; Huisstede, A. van; Birnie, E.; Biter, U.; Hiemstra, P.S.; Braunstahl, G.J. 2019
Morbidly obese subjects with airflow obstruction who underwent laparoscopic bariatric surgery appear to have the greatest risk to develop complications. In a retrospective cohort study, we... Show moreMorbidly obese subjects with airflow obstruction who underwent laparoscopic bariatric surgery appear to have the greatest risk to develop complications. In a retrospective cohort study, we identified a waist circumference >= 120 cm, smoking history >= 5PY and history of obstructive lung disease as statistically significant predictors of airflow obstruction. The resulting algorithm, aimed to identify subjects with airflow obstruction before bariatric surgery, was validated in a prospective study. The algorithm was found to be effective in identifying patients with low risk of airflow obstruction (negative predictive value 94.7%). Airflow obstruction, however, was not associated with post-operative complications as we expected. In contrast, inspiratory capacity and the Epworth Sleepiness scale were more promising predictors for post-operative complications in subjects undergoing bariatric surgery. Show less
Christen, T.; Trompet, S.; Rensen, P.C.N.; Dijk, K.W. van; Lamb, H.J.; Jukema, J.W.; ... ; Mutsert, R. de 2019
