Effects of a Lifestyle Program on Vascular Reactivity in Macro- and Microcirculation in Severely Obese Adolescents

Context and Objective: This study aimed to comprehensively assess the macro- and microcirculation of severely obese adolescents (SOA) and normal-weight counterparts and to determine the longitudinal effects of weight loss on vascular function in SOA. Design, Setting, Participants, and Outcome Measures: Seventeen SOA (body mass index z-score = 4.22 ± 0.73) and 19 puberty-matched normal-weight counterparts (body mass index z-score = −0.02 ± 1.04) were included. The SOA participated in a 4 month weight loss program. Brachial artery flow-mediated dilation and response to sublingual nitrate (nitrate-mediated dilation [NMD]) were assessed by high-resolution ultrasound. Microvascular reactivity was evaluated by laser Doppler flowmetry in response to NMD, iontophoresis of acetylcholine and sodium nitroprusside, and local hyperthermia. Plasma insulin, leptin, resistin, C-reactive protein, myeloperoxidase, and tissue plasminogen activator were measured. Results: At baseline, SOA had similar flow-mediated dilation and impaired NMD in the brachial artery compared to normal-weight adolescents. Similarly, peak responses to acetylcholine and sodium nitroprusside iontophoresis and to local hyperthermia were unaltered, whereas cutaneous blood flow after NMD was lower in the forearm microcirculation of SOA. All plasma measurements were significantly higher in SOA. After the 4-month program, SOA presented a weight reduction of 7.4 ± 3.1%, but neither brachial artery nor microvascular reactivity variables were improved. Significant decreases were detected in plasma leptin, myeloperoxidase, and tissue plasminogen activator. Conclusions: Macro- and microvascular endothelial function are preserved in adolescents with severe obesity. Conversely, weight loss does not improve their impaired smooth muscle response to exogenous organic nitrate in both vascular beds, despite reducing plasma markers adversely related to vascular homeostasis.This study was supported by grants from the French Society of Vascular Medicine 2010-2012 (to A.V. and A.P.M), and the Spanish Ministry of Health (CIBERobn CB12/03/30038) (to E.R.

Study protocol for a pragmatic cluster randomized controlled trial to improve dietary diversity and physical fitness among older people who live at home (the “ALAPAGE study”)

Background : Diet and physical activity are key components of healthy aging. Current interventions that promote healthy eating and physical activity among the elderly have limitations and evidence of French interventions’ effectiveness is lacking. We aim to assess (i) the effectiveness of a combined diet/physical activity intervention (the “ALAPAGE” program) on older peoples’ eating behaviors, physical activity and fitness levels, quality of life, and feelings of loneliness; (ii) the intervention’s process and (iii) its cost effectiveness. Methods : We performed a pragmatic cluster randomized controlled trial with two parallel arms (2:1 ratio) among people ≥60 years old who live at home in southeastern France. A cluster consists of 10 people participating in a “workshop” (i.e., a collective intervention conducted at a local organization). We aim to include 45 workshops randomized into two groups: the intervention group (including 30 workshops) in the ALAPAGE program; and the waiting-list control group (including 15 workshops). Participants (expected total sample size: 450) will be recruited through both local organizations’ usual practices and an innovative active recruitment strategy that targets hard-to-reach people. We developed the ALAPAGE program based on existing workshops, combining a participatory and a theory-based approach. It includes a 7-week period with weekly collective sessions supported by a dietician and/or an adapted physical activity professional, followed by a 12-week period of post-session activities without professional supervision. Primary outcomes are dietary diversity (calculated using two 24-hour diet recalls and one Food Frequency Questionnaire) and lower-limb muscle strength (assessed by the 30-second chair stand test from the Senior Fitness Test battery). Secondary outcomes include consumption frequencies of main food groups and water/hot drinks, other physical fitness measures, overall level of physical activity, quality of life, and feelings of loneliness. Outcomes are assessed before the intervention, at 6 weeks and 3 months later. The process evaluation assesses the fidelity, dose, and reach of the intervention as its causal mechanisms (quantitative and qualitative data). Discussion : This study aims to improve healthy aging while limiting social inequalities. We developed and evaluated the ALAPAGE program in partnership with major healthy aging organizations, providing a unique opportunity to expand its reach

Effect of Aerobic Exercise Training on Arterial Stiffness in Obese Populations: A Systematic Review and Meta-Analysis

International audienceBackground and ObjectiveControversy exists as to whether aerobic exercise training decreases arterial stiffness in obese subjects. The aim of this study was to systematically review and quantify the effect of aerobic exercise training on arterial stiffness in obese populations.MethodsMEDLINE, Cochrane, Scopus, and Web of Science were searched up until May 2013 for trials assessing the effect of aerobic training interventions lasting 8 weeks or more on arterial stiffness in obese populations (body mass index ≥30 kg/m2). Standardized mean difference (SMD) in arterial stiffness parameters (augmentation index, β-stiffness, distensibility, pulse wave velocity, arterial waveforms) was calculated using a random-effects model. Subgroup and meta-regression analyses were used to study potential moderating factors.ResultsEight trials, comprising a total of 235 subjects with an age range of 49–70 years, met the inclusion criteria. Arterial stiffness was not significantly reduced by aerobic training (SMD −0.17; 95 % confidence interval (CI) −0.39, 0.06, P = 0.14). Similarly, post-intervention arterial stiffness was similar between the aerobic-trained and control obese groups (SMD 0.02; 95 % CI −0.28, 0.32, P = 0.88). Neither heterogeneity nor publication bias were detected in these analyses. In subgroup analyses, arterial stiffness was significantly reduced in aerobic-trained subgroups having below median values in post- minus pre-intervention systolic blood pressure (SBP) (P < 0.01), exercise intensity rating score (P < 0.01), and methodological quality score (P < 0.01). Equivalent results were obtained in meta-regression analyses.ConclusionBased on current published trials, arterial stiffness is generally not reduced in middle-aged and older obese populations in response to aerobic training. However, in studies using low-intensity aerobic training and yielding a decrease in SBP, arterial stiffness may decrease. Long-term studies are needed to assess the prognostic value of these findings

Arterial stiffness in obese populations: is it reduced by aerobic training?

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ALAPAGE, une recherche interventionnelle visant à améliorer l’alimentation et l’activité physique du sujet âgé vivant à domicile

National audienceIntroduction et but de l’étude : Une alimentation adéquate et une activité physique régulière sont des éléments clés du vieillissement en bonne santé. Depuis 2016, un partenariat est engagé en PACA entre chercheurs et acteurs clés de la prévention en nutrition destinée aux seniors (Carsat Sud-Est, Mutualité Française Sud, Pôle Infos Seniors Marseille Nord). Un état des lieux a montré que l’offre d’actions de prévention en nutrition est importante dans la région, majoritairement sous forme d’ateliers de prévention collectifs, mais que l’impact de ces ateliers est peu évalué et qu’ils pourraient être améliorés. L'objectif est de présenter la recherche interventionnelle ALAPAGE (2020-2023), financée par l’IRESP. Matériel et méthodes : ALAPAGE a pour objectif d’évaluer l’impact d’une offre de prévention sur les comportements alimentaires et l’activité physique de seniors à domicile. Il s’agit : d’améliorer l’offre de prévention existante afin qu’elle favorise la participation de seniors socialement isolés et/ou économiquement vulnérables et qu’elle soit harmonisée et innovante dans sa forme et son contenu ; d’analyser les modalités de réalisation des ateliers ; d’évaluer leur impact sur l’alimentation et l’activité physique des seniors et sur leur qualité de vie ; d’estimer leur rapport coût-efficacité. ALAPAGE est un essai d’intervention contrôlé randomisé par grappes : 60 ateliers collectifs seront randomisés selon un ratio 2 : 1 (test/témoin) pour recruter 600 participants dans le groupe intervention et 300 dans le groupe témoin. Les participants (60 ans ou plus, autonomes, vivant à domicile) seront recrutés par les structures de terrain selon des modalités classiques (courriers d’information, événement d’information, affiches, etc.), et de façon active pour les seniors socialement isolés et/ou économiquement vulnérables. Les participants du groupe intervention participeront à un atelier collectif comprenant 1 séance introductive, 4 sur l'alimentation et 2 sur l'activité physique et des activités post-atelier. Les participants du groupe témoin seront invités à d’autres types d’ateliers (par ex. sur l’accès aux droits) puis pourront bénéficier d’un atelier prévention nutrition après le dernier point de l’évaluation. Résultats et Analyse statistique : L’évaluation portera sur les pratiques alimentaires (méthode d’économie expérimentale limitant les biais de déclaration) et sur l’activité physique (batterie de tests validés de la capacité physique fonctionnelle). Les critères secondaires incluent la qualité de vie, le soutien social et des facteurs sociocognitifs, tel que le sentiment d’auto-efficacité. L’évaluation des processus reposera sur l’exploitation de données quantitatives et la réalisation d’entretiens qualitatifs. Une analyse de l’ensemble des coûts unitaires et quantités nécessaires (documents, heures de travail des intervenants, etc.) sera effectuée et rapportée à l’efficacité des actions. Les mesures auront lieu à la 1 ère et à la dernière séance, puis 3 mois après. Conclusion : Les résultats de ce projet guideront les décideurs dans le choix des actions et leur dissémination. Il bénéficie d’un fort potentiel de transférabilité aux autres régions, du fait de l’importance stratégique des partenaires opérationnels et de leur structuration nationale

Mechanisms of Venoarteriolar Reflex in Type 2 Diabetes with or without Peripheral Neuropathy

International audienceThe aim of this study is to investigate the underlying mechanisms of the venoarteriolar reflex (VAR) in type 2 diabetes mellitus (T2DM), with and without peripheral neuropathy. Laser Doppler flowmetry (LDF) recordings were performed on the medial malleus and dorsal foot skin, before and during leg dependency in healthy controls, in persons with obesity, in those with T2DM, in those with T2DM and subclinical neuropathy, and in those with T2DM and confirmed neuropathy. LDF recordings were analyzed with the wavelet transform to evaluate the mechanisms controlling the flowmotion (i.e., endothelial nitric oxide-independent and -dependent, neurogenic, myogenic, respiratory and cardiac mechanisms). Skin blood perfusion decreased throughout leg dependency at both sites. The decrease was blunted in persons with confirmed neuropathy compared to those with T2DM alone and the controls. During leg dependency, total spectral power increased in all groups compared to rest. The relative contribution of the endothelial bands increased and of the myogenic band decreased, without differences between groups. Neurogenic contribution decreased in controls, in persons with obesity and in those with T2DM, whereas it increased in subclinical- and confirmed neuropathy. In conclusion, this study provides evidence that confirmed diabetic neuropathy alters the VAR through the neurogenic response to leg dependency

Effects of exercise intensity on microvascular function in obese adolescents

International audienceThe optimal exercise modality for the improvement of health-related parameters and microvascular function in obese adolescents is not yet fully understood. Therefore, this study aimed to 1) compare the microvascular phenotype of obese and normal-weight adolescents; and 2) to determine the effects of a lifestyle intervention including three months of moderate continuous training (MCT) or high-intensity interval training (HIIT) on health-related parameters and microvascular function in 29 obese adolescents. Body composition, metabolic profile, aerobic fitness and cutaneous blood flow, measured using laser Doppler flowmetry at rest and during post-occlusive reactive hyperemia, were assessed prior to and following lifestyle intervention. Sixteen normal-weight adolescents were included as reference controls for baseline microvascular parameters. At baseline, obese adolescents had higher peak blood flow, peak vascular conductance and area under the curve for post-occlusive reactive hyperemia than normal-weight adolescents. Conversely, peak blood flow, peak vascular conductance and area under the curve data remained unchanged after MCT and HIIT without intergroup differences. However, the peak/basal blood flow ratio decreased in both MCT and HIIT groups without any interaction between groups due to basal CBF increase (tendency p=0.074). Exercise training, whatever the modality, does not improve peak microcirculatory function