Exploring the Potential of a Wearable Camera to Examine the Early Obesogenic Home Environment: Comparison of SenseCam Images to the Home Environment Interview.

BACKGROUND: The obesogenic home environment is usually examined via self-report, and objective measures are required. OBJECTIVE: This study explored whether the wearable camera SenseCam can be used to examine the early obesogenic home environment and whether it is useful for validation of self-report measures. METHODS: A total of 15 primary caregivers of young children (mean age of child 4 years) completed the Home Environment Interview (HEI). Around 12 days after the HEI, participants wore the SenseCam at home for 4 days. A semistructured interview assessed participants' experience of wearing the SenseCam. Intraclass correlation coefficients (ICCs), percent agreement, and kappa statistics were used as validity estimates for 54 home environment features. RESULTS: Wearing the SenseCam was generally acceptable to those who participated. The SenseCam captured all 54 HEI features but with varying detail; 36 features (67%) had satisfactory validity (ICC or kappa ≥0.40; percent agreement ≥80 where kappa could not be calculated). Validity was good or excellent (ICC or kappa ≥0.60) for fresh fruit and vegetable availability, fresh vegetable variety, display of food and drink (except sweet snacks), family meals, child eating lunch or dinner while watching TV, garden and play equipment, the number of TVs and DVD players, and media equipment in the child's bedroom. Validity was poor (ICC or kappa <0.40) for tinned and frozen vegetable availability and variety, and sweet snack availability. CONCLUSIONS: The SenseCam has the potential to objectively examine and validate multiple aspects of the obesogenic home environment. Further research should aim to replicate the findings in a larger, representative sample

The Role of the Home Environment in Early Weight Trajectories

Dramatic increases in the prevalence of overweight and obesity have prompted a focus on prevention. Weight is known to have a strong genetic basis, but the speed of change in rates of overweight and obesity against a relatively stable gene pool suggests that exposure to an ‘obesogenic’ environment is important. The home environment is thought to play a key role in early weight trajectories, providing an avenue for long-term obesity prevention. There is evidence for associations between various aspects of the home environment and energy-balance behaviours; however, evidence for associations with weight is limited, particularly in early childhood. Few studies have used comprehensive, psychometrically-tested measures of the home environment, and no studies have tested for gene-environment interaction in the home context. This thesis uses data from the Gemini twin cohort to further examine the role of the home environment. Study one describes the development of a comprehensive measure of the home environment in early childhood, including the quantification of the extent that the home is likely to be obesogenic. Study two explores the utility of a novel tool called SenseCam to examine and validate aspects of the home environment measure. Study three identifies a number of maternal characteristics associated with the obesogenic quality of the home environment. Study four shows associations between the obesogenic quality of the home environment and energy-balance behaviours; while study five finds no association with weight. Findings from study six highlight the role of gene-environment interaction, showing that the heritability of weight is higher among children living in home environments with greater obesogenic potential. Overall, the findings of this thesis further understanding on how the home environment contributes to the development of overweight and obesity. Implications, limitations, and avenues for future research are discussed

Associations between social isolation, loneliness, and objective physical activity in older men and women

BACKGROUND: The impact of social isolation and loneliness on health risk may be mediated by a combination of direct biological processes and lifestyle factors. This study tested the hypothesis that social isolation and loneliness are associated with less objective physical activity and more sedentary behavior in older adults. METHODS: Wrist-mounted accelerometers were worn over 7 days by 267 community-based men (n = 136) and women (n = 131) aged 50-81 years (mean 66.01), taking part in the English Longitudinal Study of Ageing (ELSA; wave 6, 2012-13). Associations between social isolation or loneliness and objective activity were analyzed using linear regressions, with total activity counts and time spent in sedentary behavior and light and moderate/vigorous activity as the outcome variables. Social isolation and loneliness were assessed with standard questionnaires, and poor health, mobility limitations and depressive symptoms were included as covariates. RESULTS: Total 24 h activity counts were lower in isolated compared with non-isolated respondents independently of gender, age, socioeconomic status, marital status, smoking, alcohol consumption, self-rated health, limiting longstanding illness, mobility limitations, depressive symptoms, and loneliness (β = - 0.130, p = 0.028). Time spent in sedentary behavior over the day and evening was greater in isolated participants (β = 0.143, p = 0.013), while light (β = - 0.143, p = 0.015) and moderate/vigorous (β = - 0.112, p = 0.051) physical activity were less frequent. Physical activity was greater on weekdays than weekend days, but associations with social isolation were similar. Loneliness was not associated with physical activity or sedentary behavior in multivariable analysis. CONCLUSIONS: These findings suggest that greater social isolation in older men and women is related to reduced everyday objective physical activity and greater sedentary time. Differences in physical activity may contribute to the increased risk of ill-health and poor wellbeing associated with isolation

Sleep and energy intake in early childhood

Background And Objectives: Shorter sleep is associated with higher weight in children, but little is known about the mechanisms. The aim of this study was to test the hypothesis that shorter sleep was associated with higher energy intake in early childhood. Methods: Participants were 1303 families from the Gemini twin birth cohort. Sleep duration was measured using the Brief Infant Sleep Questionnaire when the children were 16 months old. Total energy intake (kcal per day) and grams per day of fat, carbohydrate and protein were derived from 3-day diet diaries completed by parents when children were 21 months old. Results: Shorter nighttime sleep was associated with higher total energy intake (P for linear trend=0.005). Children sleeping <10 h consumed around 50 kcal per day more than those sleeping 11–<12 h a night (the optimal sleep duration for children of this age). Differences in energy intake were maintained after adjustment for confounders. As a percentage of total energy intake, there were no significant differences in macronutrient intake by sleep duration. The association between sleep and weight was not significant at this age (P=0.13). Conclusions: This study provides the first evidence that shorter nighttime sleep duration has a linear association with higher energy intake early in life. That the effect is observed before emergence of associations between sleep and weight indicates that differences in energy intake may be a mechanism through which sleep influences weight gain

Polygenic risk for obesity and its interaction with lifestyle and sociodemographic factors in European children and adolescents

Background Childhood obesity is a complex multifaceted condition, which is influenced by genetics, environmental factors, and their interaction. However, these interactions have mainly been studied in twin studies and evidence from population-based cohorts is limited. Here, we analyze the interaction of an obesity-related genome-wide polygenic risk score (PRS) with sociodemographic and lifestyle factors for BMI and waist circumference (WC) in European children and adolescents. Methods The analyses are based on 8609 repeated observations from 3098 participants aged 2-16 years from the IDEFICS/I.Family cohort. A genome-wide polygenic risk score (PRS) was calculated using summary statistics from independent genome-wide association studies of BMI. Associations were estimated using generalized linear mixed models adjusted for sex, age, region of residence, parental education, dietary intake, relatedness, and population stratification. Results The PRS was associated with BMI (beta estimate [95% confidence interval (95%-CI)] = 0.33 [0.30, 0.37], r(2) = 0.11, p value = 7.9 x 10(-81)) and WC (beta [95%-CI] = 0.36 [0.32, 0.40], r(2) = 0.09, p value = 1.8 x 10(-71)). We observed significant interactions with demographic and lifestyle factors for BMI as well as WC. Children from Southern Europe showed increased genetic liability to obesity (BMI: beta [95%-CI] = 0.40 [0.34, 0.45]) in comparison to children from central Europe (beta [95%-CI] = 0.29 [0.23, 0.34]), p-interaction = 0.0066). Children of parents with a low level of education showed an increased genetic liability to obesity (BMI: beta [95%-CI] = 0.48 [0.38, 0.59]) in comparison to children of parents with a high level of education (beta [95%-CI] = 0.30 [0.26, 0.34]), p-interaction = 0.0012). Furthermore, the genetic liability to obesity was attenuated by a higher intake of fiber (BMI: beta [95%-CI] interaction = -0.02 [-0.04,-0.01]) and shorter screen times (beta [95%-CI] interaction = 0.02 [0.00, 0.03]). Conclusions Our results highlight that a healthy childhood environment might partly offset a genetic predisposition to obesity during childhood and adolescence.Peer reviewe

Variation in the Heritability of Child Body Mass Index by Obesogenic Home Environment

Importance: The early obesogenic home environment is consistently identified as a key influence on child weight trajectories, but little research has examined the mechanisms of that influence. Such research is essential for the effective prevention and treatment of overweight and obesity. Objective: To test behavioral susceptibility theory’s hypothesis that the heritability of body mass index (BMI) is higher among children who live in more obesogenic home environments. Design, Setting, and Participants: This study was a gene-environment interaction twin study that used cross-sectional data from 925 families (1850 twins) in the Gemini cohort (a population-based prospective cohort of twins born in England and Wales between March and December 2007). Data were analyzed from July to October 2013 and in June 2018. Exposures: Parents completed the Home Environment Interview, a comprehensive measure of the obesogenic home environment in early childhood. Three standardized composite scores were created to capture food, physical activity, and media-related influences in the home; these were summed to create an overall obesogenic risk score. The 4 composite scores were split on the mean, reflecting higher-risk and lower-risk home environments. Main Outcomes and Measures: Quantitative genetic model fitting was used to estimate heritability of age-adjusted and sex-adjusted BMI (BMI SD score, estimated using British 1990 growth reference data) for children living in lower-risk and higher-risk home environments. Results: Among 1850 twins (915 [49.5%] male and 935 [50.5%] female; mean [SD] age, 4.1 [0.4] years), the heritability of BMI SD score was significantly higher among children living in overall higher-risk home environments (86%; 95% CI, 68%-89%) compared with those living in overall lower-risk home environments (39%; 95% CI, 21%-57%). The findings were similar when examining the heritability of BMI in the separate food and physical activity environment domains. Conclusions and Relevance: These findings support the hypothesis that obesity-related genes are more strongly associated with BMI in more obesogenic home environments. Modifying the early home environment to prevent weight gain may be particularly important for children genetically at risk for obesity

Inégalités socio-économiques dans la santé : de l’épidémiologie à l’épigénétique

Depuis le XIXe siècle, l’espérance de vie a globalement augmenté dans le monde. Cependant, de larges inégalités existent toujours entre les pays. En 2019, l’espérance de vie était de 83 ans en Suisse, mais seulement de 53 années en République centrafricaine. Les inégalités de santé sont aussi observées dans les pays à revenus élevés comme la Suisse : les individus désavantagés du point de vue socio-économique, avec des ressources matérielles et non matérielles limitées (telles que les moyens financiers, les ressources intellectuelles, le prestige, le pouvoir), sont à un plus grand risque de maladies et ont une espérance de vie plus courte que les individus avantagés. Les facteurs socio-économiques peuvent impacter la santé soit directement, soit via des facteurs qui sont à la fois distribués socialement mais aussi liés à la santé, tels que l’accès aux soins, les comportements de santé, le stress psychosocial, l’exposition à des polluants environnementaux, aussi appelés « médiateurs ». Directement ou via ces facteurs « médiateurs », les facteurs sociaux impactent des processus biologiques directement liés à la santé. Afin de réduire les inégalités de santé, une approche structurelle globale semble être nécessaire. Cette approche ciblerait les différences socio-économiques et viserait à améliorer les conditions de vie où les gens travaillent et grandissent