Toward a Conversational Agent to Support the Self-Management of Adults and Young Adults With Sickle Cell Disease: Usability and Usefulness Study

Sickle cell disease (SCD) is the most common genetic blood disorder in the world and affects millions of people. With aging, patients encounter an increasing number of comorbidities that can be acute, chronic, and potentially lethal (e.g., pain, multiple organ damages, lung disease). Comprehensive and preventive care for adults with SCD faces disparities (e.g., shortage of well-trained providers). Consequently, many patients do not receive adequate treatment, as outlined by evidence-based guidelines, and suffer from mistrust, stigmatization or neglect. Thus, adult patients often avoid necessary care, seek treatment only as a last resort, and rely on self-management to maintain control over the course of the disease. Hopefully, self-management positively impacts health outcomes. However, few patients possess the required skills (e.g., disease-specific knowledge, self-efficacy), and many lack motivation for effective self-care. Health coaching has emerged as a new approach to enhance patients' self-management and support health behavior changes. Recent studies have demonstrated that conversational agents (chatbots) could effectively support chronic patients' self-management needs, improve self-efficacy, encourage behavior changes, and reduce disease-severity. To date, the use of chatbots to support SCD self-management remains largely under-researched. Consequently, we developed a high-fidelity prototype of a fully automated health coaching chatbot, following patient-important requirements and preferences collected during our previous work. We recruited a small convenience sample of adults with SCD to examine the usability and perceived usefulness of the system. Participants completed a post-test survey using the System Usability Scale and the Usefulness Scale for Patient Information Material questionnaire. Thirty-three patients participated. The majority (64%) was affected by the most clinically severe SCD genotypes (Hb SS, HbSβ0). Most participants (94%) rated the chatbots as easy and fun to use, while 88% perceived it as useful support for patient empowerment. In the qualitative phase, 72% of participants expressed their enthusiasm using the chatbot, and 82% emphasized its ability to improve their knowledge about self-management. Findings suggest that chatbots could be used to promote the acquisition of recommended health behaviors and self-care practices related to the prevention of the main symptoms of SCD. Further work is needed to refine the system, and to assess clinical validity

A medical consideration for sickle cell trait carriers in sports: example of Guadeloupe

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The role of blood rheology in sickle cell disease

International audienceStudies performed in the last decades have highlighted the need to better understand the contribution of the endothelium, vascular function, oxidative stress, inflammation, coagulation, hemolysis and vascular adhesion mechanisms to the pathophysiology of acute vaso-occlusive like events and chronic organ damages in sickle cell disease (SCD). Although SCD is a hemorheological disease, a few works focused on the contribution of blood viscosity, plasma viscosity, red blood cell deformability and aggregation in the pathophysiology of SCD. After a brief description of basic hemorheology, the present review focuses on the role of the hemorheological abnormalities in the causation of several SCD complications, mainly in sickle cell anemia and hemoglobin (Hb) SC disease. Several genetic and cellular modulators of blood rheology in SCD are discussed, as well as unresolved questions and perspectives

P194: Effet de la température environnementale et du niveau d'activité métabolique sur la régulation à court terme de l'apport énergétique

International audienceIntroduction et but de l'étude. Alors que des millions de personnes sont exposées de façon chronique ou épisodique à des températures environnementales chaudes, les recommandations d'activité physique pour la santé métabolique et cardiovasculaire sont basées sur des études exclusivement réalisées en climat tempéré. L'objectif de ce projet est d'identifier les déterminants physiologiques de la régulation de la prise alimentaire à court terme chez l'adulte sain jeune et actif, dans différentes conditions de sollicitation métabolique (repos et exercice physique sous-maximal) et de température environnementale (neutre et chaude). Il s'agira ainsi d'étudier les signaux orexigènes et anorexigènes dans ces différentes conditions. Matériel et méthodes. Les participants volontaires étaient 9 jeunes hommes sains âgés de 20,6±1,4 ans (moyenne±écart-type), et de bonne condition physique. Leur indice de masse corporelle était de 21,1±1,5 kg/m 2. L'étude clinique a été enregistrée auprès des autorités compétentes et a bénéficié des autorisations nécessaires (CPP13-018a/2013-A01037-38). Après une session d'évaluation et de familiarisation, ils ont tous participé à 4 sessions présentées en ordre aléatoire et réalisées à jeûn. Les sessions ont été réalisées dans 2 ambiances thermiques différentes (chaude : 31°c et neutre : 22°c). Elles comprenaient une période test de 40 minutes, réalisée à 2 niveaux métaboliques (repos et exercice de pédalage à 65% de la consommation maximale d'oxygène), avec des périodes d'observation préalable et successive au test. La dernière phase de chaque session incluait un repas ad libitum. Des questionnaires, des prélèvements sanguins veineux et des mesures ont été réalisées à différents moments. Certains des participants (n=6) ont également réalisé une épreuve d'hyperglycémie provoquée par voie orale dans les 2 ambiances thermiques. Des ANOVAs pour mesures répétées ont été effectuées. Résultats et analyse statistique. Le niveau d'activité métabolique (p<0,01) influence l'apport énergétique relatif, sans que l'ambiance thermique ne modifie cet apport (effet simple : p=0,741 ; interaction avec le niveau métabolique : p=0,442) : l'apport énergétique relatif à la dépense est moins importante suite à l'exercice (717±277kcal en moyenne pour les 2 climats) que dans la condition de repos (979±285kcal). Les évolutions au cours des sessions des taux sanguins de glucose et d'insuline sont affectées par l'ambiance thermique (effet ambiance thermique x effet temps : p=0,025). Le niveau métabolique (exercice vs. repos) influence ces variables, mais ne module pas l'effet du climat. Différents biomarqueurs dosés dans cette étude sont potentiellement impliqués dans l'effet anorexigène relatif de l'exercice : c'est le cas du cortisol, de l'irisine, du peptide pancréatique, et de la cholécystokinine sur lesquels un effet du niveau métabolique est observé, sans interaction avec l'ambiance thermique. Le climat chaud est caractérisé par des valeurs post-prandiales d'insulinémie (244±152 pmol/L et 379±253pmol/L en température neutre, et chaude, respectivement) et de glycémie (5,3±0,6mmol/L et 6,0±0,6mmol/L) élevées suite au repos et à l'exercice. Ces données sont confirmées par des cinétiques différentes de réponse à l'hyperglycémie provoquée

Indirect viscosimetric method is less accurate than ektacytometry for the measurement of red blood cell deformability.

International audienceThe aim of this study was to test the accuracy of viscosimetric method to estimate the red blood cell (RBC) deformability properties. Thirty-three subjects were enrolled in this study: 6 healthy subjects (AA), 11 patients with sickle cell-hemoglobin C disease (SC) and 16 patients with sickle cell anemia (SS). Two methods were used to assess RBC deformability: 1) indirect viscosimetric method and 2) ektacytometry. The indirect viscosimetric method was based on the Dintenfass equation where blood viscosity, plasma viscosity and hematocrit are measured and used to calculate an index of RBC rigidity (Tk index). The RBC deformability/rigidity of the three groups was compared using the two methods. Tk index was not different between SS and SC patients and the two groups had higher values than AA group. When ektacytometry was used, RBC deformability was lower in SS and SC groups compared to the AA group and SS and SC patients were different. Although the two measures of RBC deformability were correlated, the association was not very high. Bland and Altman analysis demonstrated a 3.25 bias suggesting a slight difference between the two methods. In addition, the limit of agreement represented 28% (>15%) of the mean values of RBC deformability, showing no interchangeability between the two methods. In conclusion, measuring RBC deformability by indirect viscosimetry is less accurate than by ektacytometry, which is considered the gold standard

Effect of heat exposure and exercise on food intake regulation: a randomized crossover study in young healthy men

International audienceObjective: the effect of physical activity on food intake regulation may be moderated by environmental temperature. The aim of the study was to determine the single and combined effects of metabolic activity and temperature on energy intake and its hormonal regulation. Methods: A randomized crossover study was conducted in the laboratory. Ten healthy and physically active young Afro-Caribbean men participated in four experimental sessions (rest at 22°C and 31°C and cycling at 60% of their maximal oxygen uptake at 22°C and 31°C, all for 40 minutes). This test period was followed by a 30-minute recovery period and then an ad libitum meal. The main outcome measures were energy balance, subjective appetite, and plasma pancreatic polypeptide (PP), cholecystokinin (CCK) and ghrelin concentrations. Results: Relative energy intake was significantly decreased whereas plasma PP was increased in the exercise conditions (p=0.004 and p=0.002, respectively). Postprandial levels of CCK were elevated only in the rest conditions. Exposure to heat induced a decrease in plasma ghrelin (p=0.031). Conclusions: Exercise induced a short-term energy deficit. However, modifications in the hormonal regulation of food intake in response to short-term heat or heat and exercise exposure seem to be minor and did not induce changes in energy intake. This trial was registered at clinicaltrials.gov as NCT02157233

Effects of oxidative stress on red blood cell rheology in sickle cell patients

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