Genetic Variants in ERAP1 and ERAP2 Associated With Immune-Mediated Diseases Influence Protein Expression and the Isoform Profile.

OBJECTIVE: Endoplasmic reticulum aminopeptidase 1 (ERAP-1) and ERAP-2, encoded on chromosome 5q15, trim endogenous peptides for HLA-mediated presentation to the immune system. Polymorphisms in ERAP1 and/or ERAP2 are strongly associated with several immune-mediated diseases with specific HLA backgrounds, implicating altered peptide handling and presentation as prerequisites for autoreactivity against an arthritogenic peptide. Given the thorough characterization of disease risk-associated polymorphisms that alter ERAP activity, this study aimed instead to interrogate the expression effect of chromosome 5q15 polymorphisms to determine their effect on ERAP isoform and protein expression. METHODS: RNA sequencing and genotyping across chromosome 5q15 were performed to detect genetic variants in ERAP1 and ERAP2 associated with altered total gene and isoform-specific expression. The functional implication of a putative messenger RNA splice-altering variant on ERAP-1 protein levels was validated using mass spectrometry. RESULTS: Polymorphisms associated with ankylosing spondylitis (AS) significantly influenced the transcript and protein expression of ERAP-1 and ERAP-2. Disease risk-associated polymorphisms in and around both genes were also associated with increased gene expression. Furthermore, key risk-associated ERAP1 variants were associated with altered transcript splicing, leading to allele-dependent alternate expression of 2 distinct isoforms and significant differences in the type of ERAP-1 protein produced. CONCLUSION: In accordance with studies demonstrating that polymorphisms that increase aminopeptidase activity predispose to immune disease, the increased risk also attributed to increased expression of ERAP1 and ERAP2 supports the notion of using aminopeptidase inhibition to treat AS and other ERAP-associated conditions.

Adolescent's perceptions of parental influences on physical activity.

BACKGROUND: Youth physical activity engagement is a key component of contemporary health promotion strategies. Parents have potential to influence the physical activity behaviours of their children. The purpose of this study was to explore associations between adolescent self-reported physical activity, parent physical activity and perceptions of parental influence as measured by the Children's Physical Activity Correlates (CPAC) questionnaire. METHODS: This investigation included a total of 146 adolescents and their parents. Self-reported measures of physical activity were obtained using the International Physical Activity Questionnaire for Adolescents and International Physical Activity Questionnaire for adolescents and their parents respectively. Adolescent perceptions of parental role modelling, support, and encouragement were measured with the parental influences scales of the CPAC. RESULTS: Ordinary least squares regression indicated that perceptions of parental role modelling (ß=197.41, 95% CI 34.33-360.49, p=0.031) was positively associated with adolescent self-reported moderate-to-vigorous physical activity with the overall model accounting for a small amount of the variance (R2=0.076). CONCLUSION: These results are in agreement with previous research indicating that parents play a small, albeit vital role in the physical activity engagement of their children. Public health campaigns with the aim of promoting youth physical activity should endeavour to incorporate parents into their interventions.

Adolescent Self-Reported Physical Activity and Autonomy: A Case for Constrained and Structured Environments?

The provision of autonomy supportive environments that promote physical activity engagement have become popular in contemporary youth settings. However, questions remain about whether adolescent perceptions of their autonomy have implications for physical activity. The purpose of this investigation was to examine the association between adolescents' self-reported physical activity and their perceived autonomy. Participants (n = 384 adolescents) aged between 12 and 15 years were recruited from six secondary schools in metropolitan Brisbane, Australia. Self-reported measures of physical activity and autonomy were obtained. Logistic regression with inverse probability weights were used to examine the association between autonomy and the odds of meeting youth physical activity guidelines. Autonomy (OR 0.61, 95% CI 0.49-0.76) and gender (OR 0.62, 95% CI 0.46-0.83) were negatively associated with meeting physical activity guidelines. However, the model explained only a small amount of the variation in whether youth in this sample met physical activity guidelines (R(2) = 0.023). For every 1 unit decrease in autonomy (on an index from 1 to 5), participants were 1.64 times more likely to meet physical activity guidelines. The findings, which are at odds with several previous studies, suggest that interventions designed to facilitate youth physical activity should limit opportunities for youth to make independent decisions about their engagement. However, the small amount of variation explained by the predictors in the model is a caveat, and should be considered prior to applying such suggestions in practical settings. Future research should continue to examine a larger age range, longitudinal observational or intervention studies to examine assertions of causality, as well as objective measurement of physical activity. Key pointsAutonomy was negatively associated with meeting physical activity recommendationsThe findings suggest that more structured environments would facilitate physical activityThe small amount of variation explained by the predictors in the model is a caveat.

Empowering sedentary adults to reduce sedentary behavior and increase physical activity levels and energy expenditure: a pilot study.

OBJECTIVE: The purpose of this study was to assess the effectiveness of a 4-week intervention in which an online personal activity monitor (Gruve-Technologies™) was used to reduce sedentary behavior among sedentary adults. METHOD: Eighteen, sedentary adult volunteers (12 men, six women, mean age 29 ± 4.0 years) were recruited to participate in the study. Time spent in sedentary activities and light-, moderate-, and vigorous-intensity physical activity and energy expenditure were assessed during waking hours using the monitor and the 7-day SLIPA Log at both baseline and post-intervention. RESULTS: A significant decrease of 33% (3.1 h/day; p < 0.001) was found between the time spent in sedentary activities measured at baseline (9.4 ± 1.1 h/day) and at the end of the 4-week intervention (6.3 ± 0.8 h/day). Consequent to the changes in sedentary time, significant increases were found in the amount of time spent in light- (45% (2.6 h/day), p < 0.001), moderate- (33% (1 h/day) p < 0.001), vigorous-intensity physical activity (39% (0.16 h/day), p < 0.001), and energy expenditure (47% (216.7 kcal/day), p < 0.001). CONCLUSION: This monitor contributes to a meaningful reduction in time spent in sedentary activities and has a large effect on energy expenditure and physical activity patterns.

Reliability of a wellness inventory for use among adolescent females aged 12-14 years.

BACKGROUND: The wellness construct has application in a number of fields including education, healthcare and counseling, particularly with regard to female adolescents. The effective measurement of wellness in adolescents can assist researchers and practitioners in determining lifestyle behaviors in which they are lacking. Behavior change interventions can then be designed which directly aid in the promotion of these areas. METHODS: The 5-Factor Wellness Inventory (designed to measure the Indivisible Self model of wellness) is a popular instrument for measuring the broad aspects of wellness amongst adolescents. The instrument comprises 97 items contributing to 17 subscales, five dimension scores, four context scores, total wellness score, and a life satisfaction index. This investigation evaluated the test-retest (intra-rater) reliability of the 5F-Wel instrument in repeated assessments (seven days apart) among adolescent females aged 12-14 years. Percentages of exact agreement for individual items, and the number of respondents who scored within ±5, ±7.5 and ±10 points for total wellness and the five summary dimension scores were calculated. RESULTS: Overall, 46 (95.8%) participants responded with complete data and were included in the analysis. Item agreement ranged from 47.8% to 100% across the 97 items (median 69.9%, interquartile range 60.9%-73.9%). The percentage of respondents who scored within ±5, ±7.5 and ±10 points for total wellness at the re-assessment was 87.0%, 97.8% and 97.8% respectively. The percentage of respondents who scored within ±5, ±7.5 and ±10 for the domain scores at the reassessment ranged between 54.3-76.1%, 78.3-95.7% and 89.1-95.7% respectively across the five dimensions. CONCLUSIONS: These findings suggest there was considerable variation in agreement between the two assessments on some individual items. However, the total wellness score and the five dimension summary scores remained comparatively stable between assessments.

The association between adolescent self-reported physical activity and wellness: the missing piece for youth wellness programs.

PURPOSE: Potential positive associations between youth physical activity and wellness scores could emphasize the value of youth physical activity engagement and promotion interventions, beyond the many established physiological and psychological benefits of increased physical activity. The purpose of this study was to explore the associations between adolescents' self-reported physical activity and wellness. METHODS: This investigation included 493 adolescents (165 males and 328 females) aged between 12 and 15 years. The participants were recruited from six secondary schools of varying socioeconomic status within a metropolitan area. Students were administered the Five-Factor Wellness Inventory and the International Physical Activity Questionnaire for Adolescents to assess both wellness and physical activity, respectively. RESULTS: Data indicated that significant associations between physical activity and wellness existed. Self-reported physical activity was shown to be positively associated with four dimensions including friendship, gender identity, spirituality, and exercise-the higher order factor physical self and total wellness, and negatively associated with self-care, self-worth, love, and cultural identity. CONCLUSION: This study suggests that relationships exist between self-reported physical activity and various elements of wellness. Future research should use controlled trials of physical activity and wellness to establish causal links among youth populations. Understanding the nature of these relationships, including causality, has implications for the justification of youth physical activity promotion interventions and the development of youth physical activity engagement programs.

Adult total wellness: group differences based on sitting time and physical activity level.

BACKGROUND: An increasing body of evidence associates a high level of sitting time with poor health outcomes. The benefits of moderate to vigorous-intensity physical activities to various aspects of health are now well documented; however, individuals may engage in moderate-intensity physical activity for at least 30 minutes on five or more days of the week and still exhibit a high level of sitting time. This purpose of this study was to examine differences in total wellness among adults relative to high/low levels of sitting time combined with insufficient/sufficient physical activity (PA). The construct of total wellness incorporates a holistic approach to the body, mind and spirit components of life, an approach which may be more encompassing than some definitions of health. METHODS: Data were obtained from 226 adult respondents (27±6 years), including 116 (51%) males and 110 (49%) females. Total PA and total sitting time were assessed with the International Physical Activity Questionnaire (IPAQ) (short-version). The Wellness Evaluation of Lifestyle Inventory was used to assess total wellness. An analysis of covariance (ANCOVA) was utilised to assess the effects of the sitting time/physical activity group on total wellness. A covariate was included to partial out the effects of age, sex and work status (student or employed). Cross-tabulations were used to show associations between the IPAQ derived high/low levels of sitting time with insufficient/sufficient PA and the three total wellness groups (i.e. high level of wellness, moderate wellness and wellness development needed). RESULTS: The majority of the participants were located in the high total sitting time and sufficient PA group. There were statistical differences among the IPAQ groups for total wellness [F (2,220)=32.5 (p<0.001)]. A Chi-square test revealed a significant difference in the distribution of the IPAQ categories within the classification of wellness [χ2 (N=226)=54.5, p<.001]. One-hundred percent (100%) of participants who self-rated as high total sitting time/insufficient PA were found in the wellness development needed group. In contrast, 72% of participants who were located in the low total sitting time/sufficient PA group were situated in the moderate wellness group. CONCLUSION: Many participants who meet the physical activity guidelines, in this sample, sit for longer periods of time than the median Australian sitting time. An understanding of the effects of the enhanced PA and reduced sitting time on total wellness can add to the development of public health initiatives.

Development and validation of a new self-report instrument for measuring sedentary behaviors and light-intensity physical activity in adults.

BACKGROUND: Low levels of physical activity and high levels of sedentary behavior (SB) are major public health concerns. This study was designed to develop and validate the 7-day Sedentary (S) and Light Intensity Physical Activity (LIPA) Log (7-day SLIPA Log), a self-report measure of specific daily behaviors. METHOD: To develop the log, 62 specific SB and LIPA behaviors were chosen from the Compendium of Physical Activities. Face-to-face interviews were conducted with 32 sedentary volunteers to identify domains and behaviors of SB and LIPA. To validate the log, a further 22 sedentary adults were recruited to wear the GT3x for 7 consecutive days and nights. RESULTS: Pearson correlations (r) between the 7-day SLIPA Log and GT3x were significant for sedentary (r = .86, P < .001), for LIPA (r = .80, P < .001). Lying and sitting postures were positively correlated with GT3x output (r = .60 and r = .64, P < .001, respectively). No significant correlation was found for standing posture (r = .14, P = .53).The kappa values between the 7-day SLIPA Log and GT3x variables ranged from 0.09 to 0.61, indicating poor to good agreement. CONCLUSION: The 7-day SLIPA Log is a valid self-report measure of SB and LIPA in specific behavioral domains.

Physical activity, sedentary behavior and total wellness changes among sedentary adults: a 4-week randomized controlled trial.

BACKGROUND: The construct of total wellness includes a holistic approach to the body, mind and spirit components of life. While the health benefits of reducing sedentary behavior and increasing physical activity are well documented, little is known about the influence on total wellness of an internet-based physical activity monitor designed to help people to achieve higher physical activity levels. PURPOSE: The purpose of this four-week, personal activity monitor-based intervention program was to reduce sedentary behavior and increase physical activity levels in daily living for sedentary adults and to determine if these changes would also be associated with improvement in total wellness. METHODS: Twenty-two men and 11 women (27 years ± 4.0) were randomly assigned to either an intervention (n = 18) or control group (n = 15). The intervention group interacted with an online personal activity monitor (Gruve Solution™) designed to reduce sedentary time and increase physical activity during activities of daily living. The control group did not interact with the monitor, as they were asked to follow their normal daily physical activities and sedentary behavior routines. The Wellness Evaluation of Lifestyle (WEL) inventory was used to assess total wellness. Sedentary time, light, walking, moderate and vigorous intensity physical activities were assessed for both intervention and control groups at baseline and at week-4 by the 7-day Sedentary and Light Intensity Physical Activity Log (7-day SLIPA Log) and the International Physical Activity Questionnaire (IPAQ). RESULTS: Significant increases in pre-post total wellness scores (from 64% ± 5.7 to 75% ± 8.5) (t(17) = -6.5, p < 0.001) were observed in the intervention group by the end of week four. Intervention participants decreased their sedentary time (21%, 2.3 hours/day) and increased their light (36.7%, 2.5 hours/day), walking (65%, 1057 MET-min/week), moderate (67%, 455 MET-min/week) and vigorous intensity (60%, 442 MET-min/week) physical activity (all p < 0.001). No significant differences for total wellness were observed between the groups at baseline and no pre-post significant differences were observed for any outcome variable in the control group. CONCLUSION: Total wellness is improved when sedentary, but sufficiently physically active adults, reduce sedentary time and increase physical activity levels (i.e. light, waking, moderate and vigorous).

Practical physical activity measurement in youth: a review of contemporary approaches.

BACKGROUND: The accurate evaluation of physical activity levels amongst youth is critical for quantifying physical activity behaviors and evaluating the effect of physical activity interventions. The purpose of this review is to evaluate contemporary approaches to physical activity evaluation amongst youth. DATA SOURCES: The literature from a range of sources was reviewed and synthesized to provide an overview of contemporary approaches for measuring youth physical activity. RESULTS: Five broad categories are described: self-report, instrumental movement detection, biological approaches, direct observation, and combined methods. Emerging technologies and priorities for future research are also identified. CONCLUSIONS: There will always be a trade-off between accuracy and available resources when choosing the best approach for measuring physical activity amongst youth. Unfortunately, cost and logistical challenges may prohibit the use of "gold standard" physical activity measurement approaches such as doubly labelled water. Other objective methods such as heart rate monitoring, accelerometry, pedometry, indirect calorimetry, or a combination of measures have the potential to better capture the duration and intensity of physical activity, while self-reported measures are useful for capturing the type and context of activity.

Do children take the same number of steps every day?

The purpose of this study was to examine the day-to-day variability in pedometer-assessed physical activity (steps/day). A total of 1,443 children aged 6-12 years from the United States (195 boys, 254 girls), Sweden (257 boys, 252 girls), and Australia (229 boys, 256 girls) wore a pedometer for 4 consecutive weekdays. Repeated measures analysis of variance was used to examine daily differences in steps/day and the coefficient of variation (CV) was calculated for each individual to describe the day-to-day variability. Overall, mean steps/day were higher among boys (14,698 +/- 3,373 steps/day) than girls (12,086 +/- 2,929 steps/day). Significant differences were found between the 4 monitoring days for the entire sample; however, the absolute mean differences were small (55-958 steps) with an overall effect size of 0.01. This trend was apparent regardless of age, gender, and country. Individual CVs ranged from approximately 2 to 88% and the overall mean CV approximated 22%. An age-related increase in the mean CV was observed between 6- and 12-year-old children. The age x gender x country interaction was not significant (P > 0.05). These findings have implications toward the proper design, analysis, and interpretation of studies regarding physical activity among children. Beyond this aspect, our results lend insight into potential age-related biological mechanisms that may also influence daily levels and patterns of physical activity.

Very short intermittent vs continuous bouts of activity in sedentary adults.

OBJECTIVE: Whether accumulating short intermittent bouts of light-to-moderate physical activity (LMPA) can elicit significant improvements in the fitness of sedentary adults, compared to one longer continuous bout. METHODS: Fifty sedentary 35- to 60-year-old adults in Hong Kong were randomly appointed to one of two gender-balanced intervention programs: Exercise Prescription Model (EPM) of 30-minute continuous activity, 3-4 days per week, or a Lifestyle group (LIFE) of 6-minute activity, 5 times per day, 4-5 days per week. Aerobic fitness (VO(2)max), mass, body composition, blood pressure, waist-to-hip ratio, and body mass index (BMI) were assessed at baseline (December 1995) and after 8 weeks. RESULTS: Nearly half of bouts by the LIFE group were < or =6 min, while 85% of the EPM bouts were > or =30 min, with no differences in additional energy expenditure between groups (EPM: 163.0+/-89.6 MET h vs LIFE: 148.2+/-71.6 MET h). Both groups significantly improved their VO(2)max, 7.4% (ES=0.36) and 5.3% (ES=0.24) for the EPM and Lifestyle groups respectively (F((1,43))=34.0, p<0.0001). CONCLUSIONS: Accumulating multiple short bouts of LMPA, of which approximately 50% were < or =6 min, can provide significant improvements in the fitness of sedentary adults that is not dissimilar as one continuous bout of similar total duration.

BMI-referenced standards for recommended pedometer-determined steps/day in children.

BACKGROUND: Recommended levels of youth physical activity (PA) should emerge from data related to important health outcomes. The purpose of the present study was to establish criterion-referenced standards for PA (using pedometer-assessed steps/day) related to healthy body composition. METHODS: This is a secondary analysis of an existing data set (including pedometer-assessed PA and objectively measured BMI) of 1,954 children (995 girls, 959 boys; ages 6-12 years) from the USA, Australia, and Sweden. The contrasting groups method [M.J. Sarif, Introduction to Measurement in Physical Education and Exercise Science, St. Louis, MO: Mosby College Publishing; 1986] for establishing criterion-referenced cut points was used to identify optimal age- and sex-specific standards for steps/day related to international BMI cut points for normal weight and overweight/obesity. RESULTS: The selected cut points for steps/day for 6-12 year olds were 12,000 steps/day for girls and 15,000 steps/day for boys. CONCLUSIONS: The analytical process undertaken in this study illuminated the difference in previously used norm-referenced standards vs. criterion-referenced standards based on BMI categories. The steps/day cut points established herein, using an international sample, are higher than previously suggested normative standards but are not inconsistent with recent advances in our understanding of PA needs in youth. This analysis provides the foundation for cross-validation and evaluation of these BMI-referenced steps/day cut points in independent samples and with longitudinal study designs.

Activity levels and body mass index of children in the United States, Sweden, and Australia.

PURPOSE: Assess the physical activity and body mass index (BMI) levels of children in the United States, Sweden, and Australia. METHODS: A total of 1954 children, 6-12 yr old (711 American, 563 Australian, and 680 Swedish) wore sealed pedometers for four consecutive days. Height and weight measures were obtained. RESULTS: Descriptive data for step counts and BMI by sex, age, and country were calculated to determine activity levels and BMI. Three-way multivariate ANOVA for step counts and BMI between countries at each age and sex found that, in general, the Swedish children were significantly more active than the Australian and American children, and the American children were significantly heavier than the Australian and Swedish children. For boys, the mean step counts ranged from 15673 to 18346 for Sweden, 13864 to 15023 for Australia, and 12554 to 13872 for America. For girls, the mean step counts ranged from 12041 to 14825 for Sweden, 11221 to 12322 for Australia, and 10661 to 11383 for America. The activity curve is somewhat level during the preadolescent years. The rate of increase in BMI with age is much greater in the American children than in the Swedish or Australian children. The percent of American, Swedish, and Australian boys classified as overweight/obese was 33.5, 16.6, and 15.8, respectively. The percent of American, Swedish, and Australian girls classified as overweight/obese was 35.6, 16.8, and 14.4, respectively. Correlation analysis found few significant negative relationships between step counts and BMI. CONCLUSIONS: American children tend to be the least active and heaviest with the greatest rate of increase in BMI. The Swedish children are the most active group followed by Australia. Swedish and Australian children maintain lower BMI throughout their prepubescent years than do the American children who have a greater percentage who are classified as overweight.