FGF19 Action in the Brain Induces Insulin-Independent Glucose Lowering

Insulin-independent glucose disposal (referred to as glucose effectiveness [GE]) is crucial for glucose homeostasis and, until recently, was thought to be invariable. However, GE is reduced in type 2 diabetes and markedly decreased in leptin-deficient ob/ob mice. Strategies aimed at increasing GE should therefore be capable of improving glucose tolerance in these animals. The gut-derived hormone FGF19 has previously been shown to exert potent antidiabetic effects in ob/ob mice. In ob/ob mice, we found that systemic FGF19 administration improved glucose tolerance through its action in the brain and that a single, low-dose i.c.v. injection of FGF19 dramatically improved glucose intolerance within 2 hours. Minimal model analysis of glucose and insulin data obtained during a frequently sampled i.v. glucose tolerance test showed that the antidiabetic effect of i.c.v. FGF19 was solely due to increased GE and not to changes of either insulin secretion or insulin sensitivity. The mechanism underlying this effect appears to involve increased metabolism of glucose to lactate. Together, these findings implicate the brain in the antidiabetic action of systemic FGF19 and establish the brain’s capacity to rapidly, potently, and selectively increase insulin-independent glucose disposal

Cross-sectional interactions between quality of the physical and social environment and self-reported physical activity in adults living in income-deprived communities

Background: Understanding the environmental determinants of physical activity in populations at high risk of inactivity could contribute to the development of effective interventions. Socioecological models of activity propose that environmental factors have independent and interactive effects of physical activity but there is a lack of research into interactive effects. Objectives: This study aimed to explore independent and interactive effects of social and physical environmental factors on self-reported physical activity in income-deprived communities. Methods: Participants were 5,923 adults in Glasgow, United Kingdom. Features of the social environment were self-reported. Quality of the physical environment was objectively-measured. Neighbourhood walking and participation in moderate physical activity [MPA] on ≥5 days/week was self-reported. Multilevel multivariate logistic regression models tested independent and interactive effects of environmental factors on activity. Results: ‘Social support’ (walking: OR:1.22,95%CI=1.06-1.41,p<0.01; MPA: OR:0.79,95%CI=0.67-0.94,p<0.01), ‘social interaction’ (walking: OR:1.25,95%CI=1.10-1.42,p<0.01; MPA: OR:6.16,95%CI=5.14-7.37,p<0.001) and ‘cohesion and safety’ (walking: OR:1.78,95%CI=1.56-2.03,p<0.001; MPA: OR:1.93,95%CI=1.65-2.27,p<0.001), but not ‘trust and empowerment’, had independent effects on physical activity. ‘Aesthetics of built form’ (OR:1.47,95%CI=1.22-1.77,p<0.001) and ‘aesthetics and maintenance of open space’ (OR:1.32, 95%CI=1.13-1.54,p<0.01) were related to walking. ‘Physical disorder’ (OR:1.63,95%CI=1.31-2.03,p<0.001) had an independent effect on MPA. Interactive effects of social and physical factors on walking and MPA were revealed. Conclusions: Findings suggest that intervening to create activity-supportive environments in deprived communities may be most effective when simultaneously targeting the social and physical neighbourhood environment

Physical Activity in Youth Dance Classes

Background and objectives: The majority of youth are not meeting the US Department of Health and Human Services physical activity guidelines. Dance is a popular activity, particularly for girls, and has the potential to increase physical activity for many youth. This study investigated physical activity of children and adolescents in 7 dance types: ballet, hip-hop, jazz, Latin-flamenco, Latin-salsa/ballet folklorico, partnered, and tap. Methods: Data were collected in 17 private studios and 4 community centers in San Diego, California. A total of 264 girls from 66 classes participated (n =154 children; n = 110 adolescents). Physical activity was measured with accelerometers, and activity levels during class were calculated. Results: Participants recorded an average of 17.2 ± 8.9 minutes of moderate-to-vigorous physical activity (36% of class), but this varied by age and dance type. For children, dance type differences were observed with percent of class in moderate-to-vigorous physical activity ranging from 13.6% (Latin-flamenco) to 57% (hip-hop). For adolescents, there were no differences across dance types. Children were more active than adolescents in all types except ballet. Children and adolescents were more active in private compared with community center classes. Conclusions: Overall, physical activity in youth dance classes was low; 8% of children and 6% of adolescents met the Centers for Disease Control and Prevention 30-minute guideline for after-school physical activity during dance. To increase physical activity in dance classes, teaching methods could be employed to increase activity in all types, or emphasis could be placed on greater participation in more active dance types