Publications

The study aim was to examine associations of neighborhood built environment and neighborhood socio-economic status (SES) with multiple physical activity (PA) behaviors, sedentary time, and obesity indicators among adolescents. Cross-sectional study of 325 adolescents aged 14–18years recruited from schools in Valencia, Spain. Participants' home neighborhoods were classified according to walkability and SES levels. Walkability was defined as an index of three built environment characteristics (i.e., residential density, land use mix, and street connectivity) based on geographic information system data. Moderate-vigorous PA (MVPA) and sedentary time were assessed using accelerometers. Active commuting to school, leisure-time PA, and time in specific sedentary activities were evaluated by questionnaire. Objectively measured weight and height were used to calculate body mass index, and percent body fat was analyzed by bioelectrical impedance. Data were collected in 2013–15. Mixed model regression analyses were performed. Analyses showed an SES-by-walkability interaction for MVPA on weekends. MVPA was highest in high-SES/high-walkable neighborhoods. Another SES-by-walkability interaction was found for sedentary minutes per weekend day. The lowest average sedentary minutes were found in high-SES/high-walkable areas. Neighborhood SES was positively related to participation in sports teams/PA classes and, negatively to time spent in sedentary behaviors. Adolescents living in lower-SES neighborhoods spent more time watching TV and had more obesity and body fat. Present findings strengthen the rationale for targeting neighborhood built and SES environments as health promotion interventions for adolescents.

We have identified TLR2 and S100A8/S100A9 as key regulators of hepatic CXCL-2 expression and neutrophil recruitment. This novel TLR2-S100A9-CXCL-2 pathway may be of use in development of new strategies for selectively manipulating neutrophils in liver disease without impairing normal wound healing and regenerative responses.

Skin cancer prevention specialists should attempt to reduce ultraviolet radiation exposure (UVR) among outdoor workers, as pointed out in a recent review.1 To address this need, Project SUNWISE, a randomized controlled sun safety intervention trial with Southern Californian United States Postal Service letter carriers, was conducted from 2001 through 2004. The intervention consisted of providing free sunscreen, free wide-brim hats, a series of 6 brief onsite educational sessions, and sun safety prompts. The primary outcome measures were validated questionnaire items that asked participants how often they had used specific sun protection strategies over the past 5 workdays while delivering mail.2, 3 They were administered at baseline and 3, 12, 24, and 36 months post-baseline. The 5 response options ranged from “never” to “always”; we considered “always” as “consistent use” in analyses. At the 2-year follow-up evaluation, participants at the intervention postal stations had significantly higher rates of consistent sunscreen use and wide-brim hat use than those at control stations.2 Details about the study procedures and sample characteristics have been published previously.2 Immediately following the 2-year evaluation, control station participants received the free items and 3 of the education sessions (i.e., introduction and protections strategies, sun safety for eyes, and recap/encouragement to maintain sun safety practices). At the intervention stations, we continued to provide free sunscreen during that year. This paper describes the behavioral outcomes at the 3-year follow-up evaluation. Evaluation cohort retention rates (of those completing questionnaires) from the 2- to 3- year follow-ups were 93.2% (927/994) for the intervention group and 94.4% (1130/1196) for the control group. The trends over 3 years in two key outcomes—consistent use of sunscreen and wide-brim hats--were analyzed using generalized linear mixed models treating 3 months, 1 year, 2 years, and 3 years as a set of repeated measures on each postal worker. In addition, we adjusted for postal workers nested within post offices within a multi-level model; the intraclass correlation coefficients for sunscreen and hats were .015 and .067, respectively. All analyses were adjusted for the baseline level of the corresponding outcome variable. For each analysis, we tested 1) the time by condition interaction, to determine if the intervention effect remained constant over time, and 2) the condition main effect. Consistent sunscreen use levels for intervention participants at the 2- and 3- year follow-ups were 39.2% and 38.3%, respectively, and for control participants, they were 26.3% and 34.3%, respectively. Wide-brim hat levels for intervention participants during these periods were 40.0% and 43.8%, respectively, and for control participants, they were 22.3% and 33.0%, respectively. Results of the analyses for each of these outcomes showed significant condition by time interaction effects (ps<0.0001), indicating that the differences between the conditions were changing over time. The table shows these patterns. For both behaviors, the change in the odds ratios from year 2 to year 3 is not due to a drop among intervention participants but rather to an increase among control group participants. We are encouraged that intervention effects were maintained at least one year after the program ended, and that once the control participants received the intervention, their consistent use of sun protection increased substantially. Table Results of generalized linear mixed-model analyses a: Patterns of odds ratios over three years of follow-up

This study examined whether physical activity (PA) and sedentary behavior mediated the relationship of neighborhood walkability with two measures of adiposity: body mass index (BMI) and waist-to-height ratio (WHTR). Twenty-four neighborhoods in Ghent, Belgium were selected, stratified by objectively assessed walkability and by socio-economic status. Participants (1200 adults aged 20–65 years) completed the International Physical Activity Questionnaire and wore an accelerometer for 7 days. Weight and height were self-reported and waist circumference was objectively measured. Accelerometer-assessed moderate-to-vigorous PA and self-reported cycling for transport mediated the associations of walkability with BMI and WHTR. Moreover, walking for transport and recreational walking significantly mediated the relationship between walkability and BMI. Sedentary behavior did not mediate associations of walkability with BMI or WHTR. These findings suggest that PA, but not sedentary behavior, is a mechanism by which walkability may affect adults’ adiposity. Planning for neighborhoods to be high in walkability could have favorable effects on physical activity and weight status.

Background: The purpose of this study was to examine the reliability and validity of a newly developed computerized Dutch version of the International Physical Activity Questionnaire (IPAQ). Methods: Subjects ( N = 53) completed the computerized IPAQ at three specified times. Subjects wore a CSA activity monitor during seven full days and simultaneously completed a 7-d physical activity diary. Finally, respondents filled out a paper and pencil IPAQ. Results: Intraclass correlation coefficient ranged from 0.60 to 0.83. Correlations for “total physical activity” between the computerized IPAQ and the CSA activity counts were moderate (min: r = 0.38; kcal: r = 0.43). Correlations with the physical activity diary were also moderate (min: r = 0.39; kcal: r = 0.46). Correlations between the computerized and the paper and pencil IPAQ were high (min: r = 0.80; kcal: r = 0.84). Conclusions: The computerized Dutch IPAQ is a reliable and reasonably valid physical activity measurement tool for the general adult population.

The MAP kinase kinase kinase TGFβ-activated kinase 1 (TAK1) is activated by TLRs, IL-1, TNF, and TGFβ and in turn activates IKK-NF-κB and JNK, which regulate cell survival, growth, tumorigenesis, and metabolism. TAK1 signaling also upregulates AMPK activity and autophagy. Here, we investigated TAK1-dependent regulation of autophagy, lipid metabolism, and tumorigenesis in the liver. Fasted mice with hepatocyte-specific deletion of Tak1 exhibited severe hepatosteatosis with increased mTORC1 activity and suppression of autophagy compared with their WT counterparts. TAK1-deficient hepatocytes exhibited suppressed AMPK activity and autophagy in response to starvation or metformin treatment; however, ectopic activation of AMPK restored autophagy in these cells. Peroxisome proliferator-activated receptor α (PPARα) target genes and β-oxidation, which regulate hepatic lipid degradation, were also suppressed in hepatocytes lacking TAK1. Due to suppression of autophagy and β-oxidation, a high-fat diet challenge aggravated steatohepatitis in mice with hepatocyte-specific deletion of Tak1. Notably, inhibition of mTORC1 restored autophagy and PPARα target gene expression in TAK1-deficient livers, indicating that TAK1 acts upstream of mTORC1. mTORC1 inhibition also suppressed spontaneous liver fibrosis and hepatocarcinogenesis in animals with hepatocyte-specific deletion of Tak1. These data indicate that TAK1 regulates hepatic lipid metabolism and tumorigenesis via the AMPK/mTORC1 axis, affecting both autophagy and PPARα activity.