Impulsivity and genetic variants in DRD2 and ANKK1 moderate longitudinal associations between sleep problems and overweight from ages 5 to 11.

OBJECTIVE: Short sleep duration and sleep problems increase risks of overweight and weight gain. Few previous studies have examined sleep and weight repeatedly over development. This study examined the associations between yearly reports of sleep problems and weight status from ages 5 to 11. Although, previous studies have shown that inter-individual differences moderate the effect of short sleep duration on weight, it is not known whether inter-individual differences also moderate the effect of sleep problems on weight. We tested how the longitudinal associations between sleep problems and weight status were moderated by impulsivity and genetic variants in DRD2 and ANKK1. DESIGN: Seven-year longitudinal study. PARTICIPANTS: A total of 567 children from the Child Development Project for the analysis with impulsivity and 363 for the analysis with genetic variants. MEASUREMENTS AND RESULTS: Sleep problems and weight status were measured by mothers' reports yearly. Impulsivity was measured by teachers' reports yearly. Six single-nucleotide polymorphisms located in DRD2 and ANKK1 were genotyped. Data were analyzed using multilevel modeling. Higher average levels of sleep deprivation across years were associated with greater increases in overweight (P=0.0024). Sleep problems and overweight were associated at both within-person across time (P<0.0001) and between-person levels (P<0.0001). Impulsivity and two polymorphisms, rs1799978 and rs4245149 in DRD2, moderated the association between sleep problems and overweight; the association was stronger in children who were more impulsive (P=0.0022), in G allele carriers for rs1799978 (P=0.0007) and in A allele carriers for rs4245149 (P=0.0002). CONCLUSIONS: This study provided incremental evidence for the influence of sleep problems on weight. Findings of DRD2, ANKK1 and impulsivity are novel; they suggest that reward sensitivity and self-regulatory abilities might modulate the influences of sleep on weight gain. The analysis of polymorphisms was restricted to European Americans and hence the results might not generalize to other populations.

Widowhood and illness: a comparison of social network characteristics in France, Germany, Japan, and the United States.

This study examined social network characteristics of adults aged 70 to 90 years in relation to widowhood and illness in France, Germany, Japan, and the United States. Participants were drawn from representative samples from each of the 4 countries (total N = 1,331). Resource deficit profiles based on whether respondents were widowed, ill, both, or neither were directly related to social network characteristics for German and Japanese adults, were differentially related by gender and age for French adults, and were not related to social networks of Americans. Country, gender, and age differences in total network size, proportion of close network members, and frequency of contact with network members are reported. Similarities and differences found in the associations between normative late-life deficits and social network characteristics in the 4 countries point to the importance of investigating sociocultural factors that mediate the impact of resource loss and afford life quality in very old age.

Friendship in childhood and adulthood: lessons across the life span.

Friendship occupies an important place in the growing body of literature in child development and gerontological research. As such, it may be useful for researchers from both fields to consider what can be learned from work carried out in each tradition. Therefore, we present a selected review of topics in friendship research across the life span. Through discussion of the value of friendship, the development of friendship, challenges to friendship, the gendered nature of friendship, and the connection between friends and family, points of commonality and contrast are identified. We conclude by presenting possible avenues for future investigation for researchers interested in friendship at any point in the life span.

Children's interactions in triads: behavioral profiles and effects of gender and patterns of friendships among members.

In all, 56 triads of same-sex 3rd-, 4th-, and 5th-grade children were observed during an intimate discussion, a cooperative puzzle task, a competitive game, and free play. Observers coded triadic interaction using a Q sort and individual process ratings. Of particular interest was how gender and the pattern of friendship ties among group members related to children's behavior. Triads of girls were more intimate, exchanged more information, and were less aggressive than were triads of boys. Analyses of within-gender variability revealed 2 prototypical types of triads among boys but only 1 among girls. Girls and boys expressed similar attitudes toward triadic interaction in postsession interviews. However, girls', but not boys', attitudes were closely linked to the quality of interactions during the session. For both sexes, interaction was not strongly influenced by the initial configuration of friendship ties among triad members.

Satisfaction with social networks: an examination of socioemotional selectivity theory across cohorts.

This study examines L. L. Carstensen's (1993, 1995) socioemotional selectivity theory within and across three cohorts spanning 4 decades. Socioemotional selectivity theory predicts that as individuals age, they narrow their social networks to devote more emotional resources to fewer relationships with close friends and family. Data from 3 cohorts of nationally representative samples were analyzed to determine whether respondents' satisfaction with the size of their social networks differed by age, cohort, or both. Results support socioemotional selectivity theory: More older adults than younger adults were satisfied with the current size of their social networks rather than wanting larger networks. These findings are consistent across all cohorts. Results are discussed with respect to social relationships across the life course.