Dirk Vissers

The Effect of Exercise on Visceral Adipose Tissue in Overweight Adults: A Systematic Review and Meta-Analysis

Excessive visceral adipose tissue appears to trigger a cascade of metabolic disturbances that seem to coexist with ectopic fat storage in muscle, liver, heart and the ß-cell. Therefore, the reduction of visceral adipose tissue potentially plays a pivotal role in the treatment of the metabolic syndrome. The purpose of this systematic review and meta-analysis is to describe the overall effect of exercise on visceral adipose tissue and to provide an overview of the effect of different exercise regimes, without caloric restriction, on visceral adipose tissue in obese persons. A systematic literature search was performed according to the PRISMA statement for reporting systematic reviews and meta-analyses. The initial search resulted in 87 articles after removing duplicates. After screening on title, abstract and full-text 15 articles (totalling 852 subjects) fulfilled the a priori inclusion criteria. The quality of each eligible study was assessed in duplicate with “The Critical Review Form for Quantitative Studies”. Using random-effects weights, the standardized mean difference (Hedges g) of the change in visceral adipose tissue was −0.497 with a 95% confidence interval of −0.655 to −0.340. The Z-value was −6.183 and the p-value (two tailed) was <0.001. A subgroup analysis was performed based on gender, type of training and intensity. Aerobic training of moderate or high intensity has the highest potential to reduce visceral adipose tissue in overweight males and females. These results suggest that an aerobic exercise program, without hypocaloric diet, can show beneficial effects to reduce visceral adipose tissue with more than 30 cm2 (on CT analysis) in women and more than 40 cm2 in men, even after 12 weeks.

Effect of Long-Term Whole Body Vibration Training on Visceral Adipose Tissue: A Preliminary Report

Aim: To determine the effect of whole body vibration (WBV), combined with caloric restriction, on weight, body composition and metabolic risk factors in overweight and obese adults. Methods: A randomized, controlled study with a 6-month intervention period and a 6-month ‘no intervention’ follow-up. 61 of the 79 participants completed the study. Data were collected at baseline and at 3, 6 and 12 months in the control group (CONTROL), the diet only group (DIET), the diet plus fitness group (FITNESS) and the diet plus WBV group (VIBRATION). Results: Weight decreased significantly in all three intervention groups. Only FITNESS and VIBRATION managed to maintain a weight loss of 5% or more in the long term. Visceral adipose tissue (VAT) changed most in VIBRATION: –47.8 ± 41.2 and –47.7 ± 45.7 cm2 after 6 and 12 months respectively compared to CONTROL (–3.6 ± 20.5 or +26.3 ± 30.6 cm2), DIET (–24.3 ± 29.8 or –7.5 ± 28.3 cm2) and FITNESS (–17.6 ± 36.6 or –1.6 ± 33.3 cm2) (p < 0.001). Conclusions: Combining aerobic exercise or WBV training with caloric restriction can help to achieve a sustained long-term weight loss of 5–10%. These preliminary data show that WBV training may have the potential to reduce VAT more than aerobic exercise in obese adults, possibly making it a meaningful addition to future weight loss programs.

Microvascular disease in chronic thromboembolic pulmonary hypertension: a role for pulmonary veins and systemic vasculature

Limited numbers of operated patients with chronic thromboembolic pulmonary hypertension (CTEPH) are refractory to pulmonary endarterectomy (PEA) and experience persistent pulmonary hypertension (PH). We retrospectively assessed lung histology available from nine patients with persistent PH (ineffective PEA (inPEA) group) and from eight patients transplanted for distal CTEPH inaccessible by PEA (noPEA group). Microscopically observed peculiarities were compared with the histology of a recently developed CTEPH model in piglets. Pre-interventional clinical/haemodynamic data and medical history of patients from the inPEA and noPEA groups were collected and analysed. Conspicuous remodelling of small pulmonary arteries/arterioles, septal veins and pre-septal venules, including focal capillary haemangiomatosis, as well as pronounced hypertrophy and enlargement of bronchial systemic vessels, were the predominant pattern in histology from both groups. Most findings were reproduced in our porcine CTEPH model. Ink injection experiments unmasked abundant venular involvement in so-called small vessel or microvascular disease, as well as post-capillary bronchopulmonary shunting in human and experimental CTEPH. Microvascular disease is partly due to post-capillary remodelling in human and experimental CTEPH and appears to be related to bronchial-to-pulmonary venous shunting. Further studies are needed to clinically assess the functional importance of this finding. Pulmonary veins and systemic vasculature contribute to microvascular disease in CTEPH http://ow.ly/yGK4U

Endothelial progenitor cells and endothelial microparticles are independent predictors of endothelial function.

OBJECTIVE To examine the degree of microvascular endothelial dysfunction in relation to classical cardiovascular risk factors, arterial stiffness, and numbers of circulating endothelial progenitor cells (EPCs) and endothelial microparticles (EMPs), in obese and normal-weight children. STUDY DESIGN Cross-sectional study with 57 obese (15.2±1.4 years) and 30 normal-weight children (15.4±1.5 years). The principal outcome was microvascular endothelial function measured with peripheral arterial tonometry. Fasting blood samples were taken for biochemical analysis and EMPs (CD31+/CD42b- particles) and EPCs (CD34+/KDR+/CD45dim/- cells) flow cytometry. Characteristics between groups were compared by use of the appropriate independent samples test; a stepwise multiple regression analysis was used to determine independent predictors of microvascular endothelial function. RESULTS Microvascular endothelial function was significantly impaired in obese children and inversely correlated with body mass index Z scores (r=-0.249; P=.021) and systolic blood pressure (r=-0.307; P=.004). The number of EPCs was significantly lower in obese children and correlated with endothelial function (r=0.250; P=.022), and the number of EMPs was significantly greater in obese children and correlated inversely with endothelial function (r=-0.255; P=.021). Multivariate analysis revealed that systolic blood pressure and numbers of circulating EPCs and EMPs are important determinants of endothelial function. CONCLUSION Obese children demonstrate impaired endothelial microvascular function, increased arterial stiffness, fewer EPCs, and more EMPs. Besides systolic blood pressure, EPC and EMP counts independently predict the presence of microvascular endothelial dysfunction.

Assessment of Endothelial Dysfunction in Childhood Obesity and Clinical Use

The association of obesity with noncommunicable diseases, such as cardiovascular complications and diabetes, is considered a major threat to the management of health care worldwide. Epidemiological findings show that childhood obesity is rapidly rising in Western society, as well as in developing countries. This pandemic is not without consequences and can affect the risk of future cardiovascular disease in these children. Childhood obesity is associated with endothelial dysfunction, the first yet still reversible step towards atherosclerosis. Advanced research techniques have added further insight on how childhood obesity and associated comorbidities lead to endothelial dysfunction. Techniques used to measure endothelial function were further brought to perfection, and novel biomarkers, including endothelial progenitor cells, were discovered. The aim of this paper is to provide a critical overview on both in vivo as well as in vitro markers for endothelial integrity. Additionally, an in-depth description of the mechanisms that disrupt the delicate balance between endothelial damage and repair will be given. Finally, the effects of lifestyle interventions and pharmacotherapy on endothelial dysfunction will be reviewed.

Diet, Exercise, and Endothelial Function in Obese Adolescents

BACKGROUND AND OBJECTIVES: Endothelial dysfunction is the first, although reversible, sign of atherosclerosis and is present in obese adolescents. The primary end point of this study was to investigate the influence of a multicomponent treatment on microvascular function. Additional objectives and end points were a reduced BMI SD score, improvements in body composition, exercise capacity, and cardiovascular risk factors, an increase in endothelial progenitor cells (EPCs), and a decrease in endothelial microparticles (EMPs). METHODS: We used a quasi-randomized study with 2 cohorts of obese adolescents: an intervention group (n = 33; 15.4 ± 1.5 years, 24 girls and 9 boys) treated residentially with supervised diet and exercise and a usual care group (n = 28; 15.1 ± 1.2 years, 22 girls and 6 boys), treated ambulantly. Changes in body mass, body composition, cardiorespiratory fitness, microvascular endothelial function, and circulating EPCs and EMPs were evaluated after 5 months and at the end of the 10-month program. RESULTS: Residential intervention decreased BMI and body fat percentage, whereas it increased exercise capacity (P < .001 after 5 and 10 months). Microvascular endothelial function also improved in the intervention group (P = .04 at 10 months; + 0.59 ± 0.20 compared with + 0.01 ± 0.12 arbitrary units). Furthermore, intervention produced a significant reduction in traditional cardiovascular risk factors, including high-sensitivity C-reactive protein (P = .012 at 10 months). EPCs were increased after 5 months (P = .01), and EMPs decreased after 10 months (P = .004). CONCLUSIONS: A treatment regimen consisting of supervised diet and exercise training was effective in improving multiple adolescent obesity-related end points.

Prognostic respiratory parameters in heart failure patients with and without exercise oscillatory ventilation — A systematic review and descriptive meta-analysis

The purpose of this review was to describe the occurrence of prognostic variables as derived from cardiopulmonary exercise testing (CPET) in patients with heart failure (HF), presenting exercise oscillatory ventilation (EOV) compared to patients without EOV. The effect of EOV on peak oxygen consumption (VO2), minute ventilation/carbon dioxide production (VE/VCO2) slope, oxygen uptake efficiency slope (OUES), rest and peak pulmonary end-tidal carbon dioxide pressure (PETCO2) was meta-analysed. A systematic search strategy was performed in five databases (Pubmed, Cochrane Library, PEDro, Science Direct and Web of Science) assessing 252 articles for eligibility. Nineteen citations met the inclusion criteria totalling 3032 patients with HF (EOV=1111; non-EOV=1921). The risk of bias was assessed by two researchers. Extracted data were pooled using random or fixed effects meta-analysis, if appropriate. The level of significance was set at p≤0.05. Overall, the presentation of EOV significantly indicated aggravated prognostic markers. Subgroup analysis revealed left ventricular ejection fraction (LVEF) and mode of CPET protocol as independent factors, whereas defining EOV significantly influenced the results. A meta-analysis of studies reporting hazard ratios for cardiovascular events demonstrated that HF patients with EOV run a fourfold risk for an adverse event compared to HF patients without EOV. In general, these findings suggest that the presence of EOV in patients with HF is associated with a deterioration of the prognostic CPET parameters. Furthermore, EOV can occur in HF patients with reduced as well as preserved ejection fraction. Further research on defining and assessing EOV in a more accurate and reproducible way is required.

Physical activity monitoring in stroke: SenseWear Pro2 Activity accelerometer versus Yamax Digi-Walker SW-200 Pedometer

Abstract Purpose: Determine validity and reliability of SenseWear Pro2 Armband (SWP2A) and Yamax Digi-Walker SW-200 Pedometer (YDWP) in stroke and healthy adults. Methods: Fifteen stroke patients and 15 healthy participants wore SWP2A on upper arm and YDWP at hip/knee. Different activities were performed: treadmill walking, walking up/down a step, cycling and walking on an even surface. Steps and Energy Expenditure (EE) were measured and compared to steps counted manually and indirect calorimetry. Repeated measurements were compared to determine reliability of both devices. Results: Spearman correlation coefficients between knee-worn YDWP and counted steps while walking on an even surface was ≥0.89 in healthy and ≥0.95 in stroke. Treadmill walking revealed high Spearman correlation coefficients in healthy individuals (rs ≥ 0.90) and at 1.5 km/h in stroke (rs = 0.69). During other activities YDWP often underestimated steps. SWP2A data revealed inconsistent results in EE and steps. Reliability tested by repeated measurements varied between 0.66 and 0.98 for YDWP and 0.61 and 0.97 for SWP2A. Conclusion: YDWP and SWP2A are both reliable. Only knee-worn YDWP is a valid device to measure steps except high intensity walking in stroke. YDWP systematically undercounts steps during other activities of short duration. This study could not demonstrate valid measurement of steps/EE in stroke using SWP2A. Implications for Rehabilitation Stroke is a disabling disease with residual neurologic deficits, which impairs mobility and predisposes them to sedentary behavior. A Yamax Digi-Walker SW-200 knee-worn pedometer showed to be a valid and reliable technique to measure ambulatory activity in stroke. A valid instrument to measure energy expenditure in stroke needs to be explored.

Overweight in Adolescents: Differences per Type of Education. Does One Size Fit All?

OBJECTIVE To assess the lifestyle and prevalence of overweight among 16- to 18-year-old adolescents attending 4 different types of secondary education (SE). DESIGN Cross-sectional school-based survey. PARTICIPANTS A community sample of 994 adolescents (body mass index [BMI]: 15-43 kg/m2). VARIABLES MEASURED Overweight and obesity were assessed by BMI. Health-related quality of life (HRQL) was assessed using the 36-item short-form (SF-36) questionnaire. The Dutch eating behavior questionnaire was administered. Lifestyle was assessed using the Baecke questionnaire and self-reported activities. ANALYSIS Prevalence of overweight, HRQL and lifestyle were assessed per type of education. Gender differences and differences between BMI-categories were analyzed. RESULTS Students in Vocational SE were significantly more likely to be overweight (18%) or obese (7.5%) compared to students in other types of SE (chi square-27.0, P < .001). HRQL was significantly lower among obese girls compared to overweight (P = .009) or normal weight girls (P < .01). Obese and overweight adolescents scored higher in restrained eating than their normal weight peers (P < .001) but lower in externally induced eating (P = .001). CONCLUSIONS AND IMPLICATIONS Lifestyle and prevalence of overweight and obesity seems to differ between different types of education. This could be of importance when making health policy decisions. Health programs should focus on types of education with the highest prevalence of overweight and obesity and should be tailor-made to the specific needs of the targeted type of education.

Metabolic syndrome in youth: a cross‐sectional school‐based survey

Aim: To assess the prevalence of metabolic syndrome (MetS) among students attending vocational secondary school (VSE). VSE provides practice‐oriented education in which young people learn a specific occupation. Previously we reported VSE to be the type of education with the highest prevalence of overweight and obesity.