To examine “travel by walking” (TBW) before and after school among eighth grade girls.
Participants attended 36 middle schools from Arizona, Maryland, Minnesota, New Orleans, California and South Carolina participating in the Trial of Activity for Adolescent Girls (TAAG). The cross-sectional sample consisted of 3,076 eighth grade girls, and the longitudinal sample included 1,017 girls who participated in both 6th and 8th grades. Travel by walking before or after school status was determined from the 3-Day Physical Activity Recall (3DPAR). The main outcomes were body mass index (BMI) and physical activity, which was measured by accelerometry, estimated for total physical activity (light, moderate, vigorous) and moderate to vigorous physical activity (MVPA).
Eighth grade girls who reported TBW had 4 more minutes (95% confidence interval ([CI], 2.1–6.1.) of MVPA before and after school than non-walkers, and 2 more minutes of MVPA (95% CI, 1.1–3.1) on an average weekday. In the longitudinal sample, girls who reported TBW before and after school in both 6th and 8th grades (consistent walkers) accumulated more minutes of MVPA for an average weekday than inconsistent walkers in both sixth (27 min.±2.2 vs. 25 min.±1.9; p=.03) and eighth grades (28 min.±2.6 vs. 25 min.±2.3; p=.003). There were no differences in BMI by walking status.
Adolescent girls who reported TBW before and after school accumulated more minutes of MVPA than non-walkers. Efforts to prevent the decline in walking to school in middle school girls could contribute to their overall physical activity.
Active travel; Adolescents; Girls; Physical activity; School; Travel by walking; Transportation
The authors examined the association between life events and antihypertensive medication adherence in older adults and the moderating role of coping. A cross-sectional analysis was conducted by using data (n = 1,817) from the Cohort Study of Medication Adherence among Older Adults (recruitment conducted from August 2006 through September 2007). Life events occurring in the 12 months preceding the study interview were assessed via the Holmes Rahe Social Readjustment Rating Scale (SRRS), and coping levels were assessed via an adapted version of the John Henry Active Coping Scale. Low adherence to antihypertensive medication was defined as scores less than 6 on the 8-item Morisky Medication Adherence Scale (known as “MMAS-8”). Of study participants, 13.2% had low adherence, and 27.2% and 5.0% had medium (150–299) and high (≥300) SRRS scores, respectively. After multivariable adjustment, the odds ratios for low adherence associated with medium and high, versus low, SRRS were 1.50 (95% confidence interval: 1.11, 2.02) and 2.11 (95% confidence interval: 1.24, 3.58), respectively. When multivariable models were stratified by coping level, the association between life events and adherence was evident only among participants with low coping levels.
coping; hypertension; medication adherence; older adults; stress
To examine sedentary and light activity in relation to overweight in adolescent girls.
Methods and Procedures
Adolescent girls were randomly recruited from thirty-six schools participating in the Trial of Activity for Adolescent Girls (TAAG). Assessments included age, ethnicity, socioeconomic status, and body composition estimated from weight, height, and triceps skinfold. Sedentary and light activity was measured for six days using accelerometry in 6th and in 8th grade among two randomly sampled cross sections of girls.
Sedentary activity increased from the 6th to 8th grade by 51.5 minutes/day. In the 8th grade, a significantly higher number of hours in sedentary activity for each of the 6-days of measurement were evident with higher tertiles of percent body fat (30-35%, >35% fat) (P<0.05), but not across all increasing tertiles of BMI (5th-85th, 85-95th, and >95th percentiles). The increase in sedentary activity was observed on weekdays, but not on weekends for percent body fat tertiles. In the cohort of girls measured in both 6th and 8th grades, the mean cross-sectional coefficient estimates were significant for percent body fat, but not BMI for sedentary and light activities.
Adolescent girls from the 6th to 8th grade are shifting their time from light to more sedentary activity as measured by accelerometers. In addition, the increase in sedentary activity is not associated with an adverse effect on BMI or percent body fat. The eventual impact of this shift to a more sedentary lifestyle on body composition and other outcomes needs to be evaluated further.
Activity monitors; physical activity; overweight
Few data are available on the predictors of decline in antihypertensive medication adherence and the association of decline in adherence with subsequent blood pressure (BP) control. The current analysis included 1,965 adults from the Cohort Study of Medication Adherence among Older Adults (CoSMO) recruited between August 2006 and September 2007. Decline in antihypertensive medication adherence was defined as a ≥ 2 point decrease on the 8-item Morisky Medication Adherence Scale assessed during telephone surveys 1 and 2 years following baseline. Risk factors for decline in adherence were collected using telephone surveys and administrative databases. BP was abstracted from outpatient records. The annual rate for a decline in adherence was 4.3% (159 participants experienced a decline). After multivariable adjustment, a decline in adherence was associated with an odds ratio (OR) for uncontrolled BP (≥140/90 mm Hg) at follow up of 1.68 (95% CI: 1.01, 2.80). Depressive symptoms (OR 1.84, 95%CI 1.20, 2.82) and a high stressful life events score (OR 1.68, 95% CI 1.19, 2.38) were associated with higher ORs for a decline in adherence. Female gender (OR 0.61, 95% CI 0.42, 0.88); being married (OR 0.68, 95% CI 0.47, 0.98); and calcium channel blocker use (OR 0.68, 95% CI 0.48, 0.97) were associated with lower ORs for decline. In summary, a decline in antihypertensive medication adherence was associated with uncontrolled BP. Modifiable factors associated with decline were identified. Further research is warranted to determine if interventions can prevent the decline in antihypertensive medication adherence and improve BP control.
hypertension; medication adherence; blood pressure control; older women and men; cohort; risk factors
Purpose: health-related quality of life (HRQOL) is an important psycho-social characteristic which may impact an individual’s ability to manage their chronic disease. We examined the association between HRQOL and antihypertensive medication adherence in older adults.
Methods: participants were part of a cohort study of older adults enrolled in a managed care organisation and treated for hypertension (n = 2,180). Physical and Mental Component Summary Scores (PCS and MCS) of HRQOL were assessed using the RAND Medical Outcomes Study 36-item tool. Adherence to antihypertensive medication was assessed with the eight-item Morisky Medication Adherence Scale.
Results: the mean age of participants was 75.0 ± 5.6 years, 69.3% were white, 58.5% were women and 14.1% had low antihypertensive medication adherence. Low HRQOL scores were associated with lower levels of antihypertensive medication adherence in older adults. After adjustment for covariates, those with low PCS and MCS scores were 1.33 (95% CI 1.01, 1.74) and 2.26 (95% CI 1.74, 2.97) times more likely, respectively, to have low antihypertensive medication adherence than those with PCS and MCS scores in the top 2 tertiles.
Conclusions: low HRQOL may be an important barrier to achieving high medication adherence.
HRQOL; medication adherence; hypertension; older adults; elderly
Little is known about the associations between depressive symptoms, social support and antihypertensive medication adherence in older adults.
We evaluated the cross-sectional and longitudinal associations between depressive symptoms, social support and antihypertensive medication adherence in a large cohort of older adults.
A cohort of 2,180 older adults with hypertension was administered questionnaires, which included the Center for Epidemiologic Studies-Depression Scale, the Medical Outcomes Study Social Support Index, and the hypertension-specific Morisky Medication Adherence Scale at baseline and 1 year later.
Overall, 14.1% of participants had low medication adherence, 13.0% had depressive symptoms, and 33.9% had low social support. After multivariable adjustment, the odds ratios that participants with depressive symptoms and low social support would have low medication adherence were 1.96 (95% confidence interval (CI) 1.43, 2.70) and 1.27 (95% CI 0.98, 1.65), respectively, at baseline and 1.87 (95% CI 1.32, 2.66) and 1.30 (95% CI 0.98, 1.72), respectively, at 1 year follow-up.
Depressive symptoms may be an important modifiable barrier to antihypertensive medication adherence in older adults
Hypertension; Medication adherence; Depressive symptoms; Social support; Medication possession ratio; Older adults
A need exists to better understand multilevel influences on physical activity among diverse samples of girls. This study examined correlates of moderate-to-vigorous physical activity (MVPA) among adolescent girls from different racial/ethnic backgrounds.
1,180 6th grade girls (24.5% black, 15.7% Hispanic and 59.8% white) completed a supervised self-administered questionnaire that measured hypothesized correlates of PA. MVPA data were collected for six days using the ActiGraph accelerometer. Hierarchical regression analysis was used to examine correlates of PA in each racial/ethnic group.
Hispanic girls (n=185) engaged in 21.7 minutes of MVPA per day, black girls (n=289), 19.5 minutes and white girls (n=706), 22.8 minutes. Perceived transportation barriers (+; p=0.010) were significantly and positively related to MVPA for Hispanic girls. For black girls, Body Mass Index (BMI) (−; p=0.005) and social support from friends (+; p=0.006) were significant correlates of MVPA. For white girls, BMI (−; p <0.001), barriers (−; p=0.012), social support from friends (+; p=0.010), participation in school sports (+; p=0.009), and community sports (+; p=0.025) were significant correlates of MVPA. Explained variance ranged from 30 to 35%.
Correlates of MVPA varied by racial/ethnic groups. Effective interventions in ethnically diverse populations may require culturally tailored strategies.
Black; Hispanic; white; race/ethnicity analysis; accelerometry
Process evaluation is a necessary component of randomized controlled field trials. This is a descriptive paper that reviews process evaluation for the ACTION Wellness Program for Elementary School Personnel.
Methods included self-report by participants, documentation by program staff, and school administrator report. Variables evaluated were program dose, fidelity and reach, exposure to materials and activities, and school factors that could influence program implementation and/or outcomes.
Dose and exposure were high across intervention schools and intervention years. Reach was variable across schools and activities. Schools on the East Bank of the Mississippi River generally had slightly better reach than schools on the West Bank. Some nutrition activities had higher levels of participation than physical activities.
High program dose reflected good effort and cooperation by program staff and schools. A disconnect between exposure and reach showed that high exposure did not always translate to high participation.
To determine the association between complementary and alternative medicine (CAM) use and antihypertensive medication adherence in older black and white adults.
Patients enrolled in a managed care organization
2180 black and white adults, 65 years of age and older and prescribed antihypertensive medication.
CAM use (i.e., health food and herbal supplements, relaxation techniques) for blood pressure control as well as antihypertensive medication adherence were collected via telephone survey between August 2006 and September 2007. Low medication adherence was defined as scores < 6 using the 8-item Morisky Medication Adherence Scale.
The mean age of participants was 75.0 + 5.6 years, 30.7% were black, 26.5% used CAM, and 14.1% had low antihypertensive medication adherence. In managing blood pressure, 30.5% of black and 24.7% of white participants used CAM in the last year and 18.4% of black and 12.3% of white participants reported low adherence to antihypertensive medication (P=0.005 and <0.001, respectively). After multivariable adjustment for socio-demographics, depressive symptoms and reduction in antihypertensive medications due to cost, the prevalence ratios of low antihypertensive medication adherence associated with CAM use were 1.56 (95% CI: 1.14–2.15; P=0.006) and 0.95 (95% CI 0.70, 1.29; P=0.728) among blacks and whites, respectively (P value for interaction=0.069).
In this cohort of older managed care patients, CAM use was associated with low adherence to antihypertensive medication among blacks but not whites.
complementary and alternative medicine; hypertension; medication adherence; older adults
Little is known about the dietary intake of school employees, a key target group for improving school nutrition.
To investigate selected dietary variables and weight status among elementary school personnel.
Cross-sectional, descriptive study.
Elementary school employees (n=373) from 22 schools in a suburban parish (county) of southeastern Louisiana were randomly selected for evaluation at baseline of ACTION, a school-based worksite wellness trial.
Two 24-hour dietary recalls were administered on non-consecutive days by registered dietitians using the Nutrition Data System for Research. Height and weight were measured by trained examiners and body mass index calculated as weight (kilograms)/height (meters squared).
Statistical analyses performed
Descriptive analyses characterized energy, macronutrient, fiber, and MyPyramid food group consumption. Inferential statistics (t-tests, analysis of variance, chi-square) were used to examine differences in intake and compliance with recommendations by demographic and weight status categories.
Approximately 31% and 40% of the sample were overweight and obese, respectively, with higher obesity rates than state and national estimates. Mean daily energy intake among women was 1862 kilocalories (kcal) (±492) and among men was 2668 kcal (±796). Obese employees consumed more calories (+288 kcal, p<0.001) and more calories from fat (p<0.001) than those who were normal weight. Approximately 45% of the sample exceeded dietary fat recommendations. On average, only 9% had fiber intakes at or above their Adequate Intake, which is consistent with the finding that over 25% of employees did not eat fruit, 58% did not eat dark green vegetables, and 45% did not eat whole grains on the recalled days. Only 7% of employees met the MyPyramid recommendations for fruits or vegetables, and 14% of the sample met those for milk and dairy foods.
These results suggest that greater attention be directed to understanding and improving the diets of school employees given their high rates of overweight and obesity, poor diets, and important role in student health.
school employees; MyPyramid; macronutrients
Energy density (kJ/g) may have a strong influence on energy balance. Although beverages are a considerable source of energy in the US diet, rarely have studies among free-living populations investigated the energy density of foods (EDF) and the energy density of beverages (EDB) simultaneously. We examined the independent simultaneous associations of EDF and EDB on energy intake and Body Mass Index (BMI) in adult women.
This cross-sectional design focused on 348 elementary school employees randomly selected at baseline of a worksite wellness trial in southeastern Louisiana. Two 24-hour recalls were collected, and measured heights and weights were converted into BMI (kg/m2).
Those in the highest EDF tertile consumed more energy and had higher BMIs than those in the lowest tertile (P<0.05). Employees in the highest EDB tertile consumed more energy than those in the lowest, yet there was no difference in BMIs between the two groups. Multivariate regression, with controls for demographic and health variables, confirmed the positive association between EDF and BMI; a 1 kJ/g increase in EDF was associated with a 0.39 kg/m2 increase in BMI (P=0.038). Models that did not control for EDB gave estimates of EDF that were 8% to 10% lower.
These findings suggest that EDF and EDB play important, yet distinct, roles in energy intake and BMI. Future studies should evaluate both types of energy density as independent predictors since our results suggest that EDB can confound the association of EDF with BMI.
energy density; energy intake
A positive outcome in self-reported behavior could be detected erroneously if an intervention caused over-reporting of the targeted behavior. Data collected from a multi-site randomized trial were examined to determine if adolescent girls who received a physical activity intervention over-reported their activity more than girls who received no intervention.
Activity was measured using accelerometers and self-reports (3-Day Physical Activity Recall, 3DPAR) in cross-sectional samples pre- (6th grade, n=1464) and post-intervention (8th grade, n=3114). Log-transformed accelerometer minutes were regressed on 3DPAR blocks, treatment group, and their interaction, while adjusting for race, BMI, and timing of data collection.
Pre-intervention, the association between measures did not differ between groups, but post-intervention 3DPAR blocks were associated with fewer log-accelerometer minutes of moderate-vigorous physical activity (MVPA) in intervention girls than control girls (p = 0.002). The group difference was primarily in the upper 15% of the 3DPAR distribution, where control girls had >1.7 more accelerometer minutes of MVPA than intervention girls who reported identical activity levels. Group differences in this sub-sample were 8.5–16.2% of the mean activity levels; the intervention was powered to detect a difference of 10%.
Self-report measures should be interpreted with caution when used to evaluate a physical activity intervention.
bias (epidemiology); intervention studies; adolescent; exercise; questionnaires; social desirability
To determine the annual rate at which physical activity changes in girls during middle school using both objective and self-report measures of physical activity.
Participants were 6th and 8th grade girls from the control schools in the Trial of Activity for Adolescent Girls (TAAG). Random cross-sectional samples initially were drawn from 6th grade girls (n=786) and two years later from 8th grade girls (n=1545). A cohort of 501 girls was in both the 6th and the 8th grade samples. The girls wore an accelerometer for six days and completed the 3-Day Physical Activity Recall (3DPAR). Data were summarized using 3.0–4.6- and 6.5-MET cutpoints for accelerometry and self-reported physical activity. Analyses were performed using repeated measures ANOVA in PROC MIXED.
More than 40% of the girls were White, approximately 20% were African-American, and 20% were Hispanic. The annual percent decrease in physical activity in the cross-sectional sample was approximately 4% (−1.76 min MVPA/day), using accelerometer data. The percent decrease in physical activity based on self-report data was higher, 6–13%, depending on the physical activity variable. Declines tended to be larger in African-American girls, but the ethnic differences were not statistically significant.
Based on comparisons of cross-sectional samples of 6th and 8th grade girls, objectively-measured physical activity declined at a rate of 4% per year.
physical activity; adolescents; girls; middle school; accelerometry
The availability of self-report scales that accurately identify low adherers to antihypertensive medication in real time could improve outpatient management of this disease. We evaluated the association and concordance of the new 8-item self-report Morisky Medication Adherence Scale (MMAS) with pharmacy fill data in a sample of community dwelling seniors with hypertension.
Pharmacy records for antihypertensive medications were abstracted for managed care adult hypertensive patients, ≥65 years, who completed a survey that included the 8-item MMAS (n=87). Continuous single-interval medication availability (CSA), medication possession ratio (MPR), and continuous multiple-interval medication gaps (CMG) were calculated using pharmacy data. MMAS adherence was categorized as high, medium, and low (MMAS scores of 8, 6 to <8, and <6, respectively); pharmacy fill non-persistency was defined as <0.8 for CSA and MPR and >0.2 for CMG.
Overall, 58%, 33%, and 9% of participants had high, medium, and low medication adherence by MMAS. After adjustment for demographics and compared to high adherers on MMAS, patients with low MMAS adherence were 6.89 (95% confidence interval (CI): 2.48 – 19.1) times more likely to have non-persistent pharmacy fill rates by CSA and 5.22 (95% CI:1.88 – 14.5) times more likely to have non-persistent pharmacy fill rates by MPR. Concordance between MMAS and CSA, MPR, and CMG was ≥75%.
The MMAS is significantly associated with anti-hypertensive pharmacy refill adherence. Although further validation of the MMAS is needed, it may be useful in identifying low medication adherers in clinical settings.
medication adherence; hypertension; Morisky Medication Adherence Scale; pharmacy fill; managed care
Rates of obesity among children have been rising in recent years. Information on the prevalence of obesity in children living in rural communities is needed. We report the prevalence of overweight and obesity in children enrolled in grades 4 to 6 who live in rural areas of Louisiana, U.S.
Methods and Procedures
These data were collected as baseline assessment for the Louisiana (LA) Health project. Height, weight, and estimates of body fat (using body impedance analysis) were collected on 2709 children. Average age was 10.5 years and the sample composition was 57.3% girls, 61.7% African-American, 36.0% Caucasian, and 2.3% other minority. A majority of children (77%) met the criterion for poverty status.
The distribution of body mass index (BMI) percentile was highly skewed toward obesity. The most frequent BMI percentile scores were 98th and 99th percentile. Using Centers for Disease Control and Prevention (CDC) norms, the overall prevalence of obesity was 27.4% and for overweight was 45.1% of which 17.7% were between the 85th and 95th percentile. The prevalence of childhood overweight and obesity were much higher than the national norm and this increased prevalence was observed in both genders and in Caucasian and African American children.
The prevalence of childhood overweight and obesity was found to be much higher in rural and primarily poor (77%) children living in Louisiana when compared to national norms. This observation suggests that rural children from Louisiana may be experiencing an epidemic of obesity that exceeds national prevalence estimates.
childhood obesity; population studies; rural health; childhood gender differences; ethnicity
In light of challenges imposed by the changing media landscape and decreasing classroom time available for health interventions, new approaches are needed to disseminate anti-tobacco messages to adolescents. This study reported process evaluation of an in-school three-year anti-tobacco media campaign conducted in 10 schools in Louisiana.
Over three years, 10 schools received an in-school anti-tobacco media campaign. The media campaign was one intervention component of the Acadiana Coalition of Teens against Tobacco. Campaign measures were tracked over the campaign's three-year duration. The campaign and evaluation were designed to target the students as they progressed through high school. The number of students who completed the surveys were 1,823 in Year 1, 1,552 in Year 2, and 1,390 in Year 3. Schools eligible for participation were publicly funded schools with no magnet or special populations and within a two-hour driving distance of the New Orleans study office.
In a self-report survey (Year 1, n=1,823; Year 2, n=1,552; Year 3, n=1,390), more than 75% and 50% of students reported being exposed to posters and public service announcements, respectively. Recognition of campaign theme was more than 80%. Almost half of respondents reported that the posters were interesting, one-third reported that the posters prevented them from smoking, and 10% reported that the posters encouraged them to cease smoking. Stock media posters had a significantly higher affective reaction than the customized media posters.
Findings suggest that in-school media programs are useful and should be considered as a viable approach to health education for adolescents.
Social–ecological (SE) models are becoming more widely used in health behavior research. Applying SE models to the design of interventions is challenging because models must be tailor-made for each behavior and population, other theories need to be integrated into multilevel frameworks, and empirical research to guide model development is limited. The purpose of the present paper is to describe a SE framework that guided the intervention and measurement plans for a specific study. The trial of activity for adolescent girls (TAAG) is a multi-center study of interventions to reduce the decline of physical activity in adolescent girls. The TAAG framework incorporates operant learning theory, social cognitive theory, organizational change theory and the diffusion of innovation model in a multi-level model. The explicit and practical model developed for TAAG has already benefited the study and may have elements that can generalize to other health promotion studies.
The co-use of alcohol and tobacco by adolescents is a public health problem that continues well into adulthood and results in negative behavioral, social, and health consequences. The purpose of this study was to examine the co-use of alcohol and tobacco among ninth-graders in south-central Louisiana.
We created a health habits survey to collect data from 4,750 ninth-grade students, mean age 15.4 years. Cross-sectional analysis used χ
2, 1-way analysis of variance, and logistic regression methods.
Almost 20% of students were co-users. Students who were white, performed poorly in school, did not expect to graduate high school, and had more discretionary money to spend were more likely to be co-users. Co-users had friends who got drunk weekly and were more likely to approve of alcohol use among friends than among adults. Significant differences in attitudes toward drinking and smoking were observed between co-users and nonusers. For adolescent drinkers, including girls, hard liquor was the preferred beverage.
These data for high school students are applicable for prevention strategies at a critical age when harmful health behaviors can mark the start of lifelong habits. Intervention efforts will be successful only if they account for multiple levels of influence.
This study describes the relationships between sedentary activity and body composition in 1,458 sixth-grade girls from 36 middle schools across the United States. Multivariate associations between sedentary activity and body composition were examined with regression analyses using general linear mixed models. Mean age, body mass index, and percentage of body fat were 12.0 ± 0.51, 21.1 kg/m2 ± 4.8, 28.5 ± 8.9, respectively. Girls averaged 7.7 ± 1.2 sedentary hours per day and about 13 hr (~ 97% of the day) of both sedentary and light activities. Overweight girls were significantly more (13 min; p < .003) sedentary, especially after school (> 2 p.m.; p < .01), and less physically active (p < .0001) than normal weight girls. The study documents small but significant associations between sedentary activity and adiposity.
accelerometry; body fat; body mass index; sedentary behavior
A school-based environmental program to reduce adolescent smoking was conducted in 20 schools (10 intervention; 10 control) in south central Louisiana. The 9th grade cohort (n = 4,763; mean age = 15.4 yrs; 51% female; 61% Caucasian; 30-day smoking prevalence at baseline = 25%) was followed over four years for 30-day smoking prevalence with the school as the unit of analysis. Although prevalence decreased in intervention schools and increased in control schools in Year 2 the significant difference between the two groups at baseline was not overcome by the intervention and increases in prevalence were observed in both groups in Years 3 and 4. The higher the percentage of white students in a school the higher the prevalence rates regardless of intervention/control status. Boys’ and girls’ smoking rates were similar. These outcome data, student feedback and process evaluation provide a basis for continuing to create more innovative adolescent tobacco control programs.
Smoking prevalence; adolescents; high school; health promotion
This study was designed to examine the associations of physical activity and body composition with cardiorespiratory fitness in eighth grade girls.
A random sample of 1440 eighth grade girls at 36 schools participated in this cross-sectional investigation, which represented an ethnically and geographically diverse group. Cardiorespiratory fitness was assessed using a modified physical work capacity test on a cycle ergometer that predicted workload at a heart rate of 170 beats·min−1. Physical activity was assessed over 6 d in each girl using an accelerometer and body composition was estimated from body mass index and triceps skinfolds using a previously validated equation. Pearson correlations and multiple regression analyses were used to determine the relationships among fitness, physical activity, and body composition.
Significant linear relationships among cardiorespiratory fitness, body composition, and physical activity were found. The combination of fat and fat-free mass along with racial group and a race by fat-free-mass interaction accounted for 18% (R2) of the variation in physical fitness. Adding moderate-to-vigorous physical activity to the regression model increased the R2 to 22%. Black girls had somewhat lower fitness levels (P < 0.05) especially at higher levels of fat and fat-free mass than other racial/ethnic groups.
Physical activity, fat-free mass, and the interaction between fat-free mass and racial group are significantly associated with cardiorespiratory fitness in adolescent girls.
ADOLESCENT; FATNESS; ACCELEROMETRY; PHYSICAL FITNESS; RACE/ETHNICITY
To describe the objectively-measured physical activity (PA) characteristics of a diverse sample of 6th grade girls, to examine influences on PA, and to report compliance with PA guidelines.
Six locations across the United States.
1578 6th grade girls. Actigraph accelerometers were worn for 7 days, and data for 6 days were included in the analyses.
Race/ethnicity, free-or-reduced price lunch (FRPL), and geographic region
Main outcome measure
Six operational definitions of adequate activity (60 min or 30 min of daily MVPA at or above 4.6, 3.8 or 3.0 METS (metabolic equivalents)) were applied to examine whether girls met physical activity guidelines.
Average time spent in sedentary, light, moderate, and vigorous activities was 460, 342, 18, and 6 min/day, respectively. White girls were more active than girls in other race/ethnic groups, and girls who did not receive FRPL were more active than girls who did. Girls in western states were most active. Percentages of girls in compliance with the 6 thresholds for adequate activity varied widely, and ranged from 0.6% to 99.8%.
When physical activity is measured objectively and a 4.6 MET cutpoint for MVPA is applied, most 6th grade girls fall below guidelines for adequate physical activity. One notable finding was the impact of different accelerometer scoring protocols on estimates of compliance. Conceptual and empirical work is needed to define appropriate physical activity for youth using objective physical activity measures.
To assess girls' physical activity (PA) in middle school physical education (PE) as it relates to field site, lesson context and location, teacher gender, and class composition.
We observed girls' PA levels, lesson contexts, and activity promotion by teachers in 431 lessons in 36 schools from six field sites participating in the Trial of Activity for Adolescent Girls. Interobserver reliabilities exceeded 90% for all three categories. Data were analyzed using mixed-model ANOVA with controls for clustering effects by field site and school.
Mean lesson length was 37.3 (± 9.4) min. Time (13.9 ± 7.0 min) and proportion of lessons (37.9 ± 18.5%) spent in moderate to vigorous PA (MVPA), and time (4.8 ± 4.2 min) and proportion of lessons (13.1 ± 11.7%) in vigorous PA (VPA) differed by field site (P < 0.004). Lesson time for instructional contexts differed by field site, with overall proportions as follows: game play (27.3%), management (26.1%), fitness activities (19.7%), skill drills (12.1%), knowledge (10.6%), and free play (4.4%). Coed classes were 7.9 min longer than girls-only classes (P = 0.03). Although 27 s shorter, outdoor lessons were more intense (MVPA% = 45.7 vs 33.7% of lesson, P < 0.001) and provided 4.0 more MVPA minutes (P < 0.001). MVPA, VPA, and lesson contexts did not differ by teacher gender. There was little direct promotion of PA by teachers during lessons.
Substantial variation in the conduct of PE exists. Proportion of lesson time girls spent accruing MVPA (i.e., 37.9%) fell short of the Healthy People 2010 objective of 50%. Numerous possibilities exist for improving girls' PA in PE.
CHILDREN; EXERCISE; FEMALES; INTERVENTION; PHYSICAL; SPORTS
An understanding of the relation in adolescents between serum homocysteine and foods rich in vitamin B-6, vitamin B-12, and folate is important because high homocysteine concentrations in childhood and adolescence may be a risk factor for later cardiovascular disease. However, little is known about the relation between food intake and homocysteine in adolescents.
Five years after national folic acid fortification of enriched grain products, cross-sectional relations between food intake and serum homocysteine concentrations were examined in 2695 adolescents [x̄ age: 18.3 (range: 15−20) y] enrolled in the Child and Adolescent Trial for Cardiovascular Health.
A nonfasting blood specimen was analyzed for serum homocysteine, folate, and vitamins B-6 and B-12. Dietary intake was assessed by using a food-frequency questionnaire. Multiple regression analyses were used to evaluate the relation of intakes of whole grains, refined grains, fruit, vegetables, dairy products, red and processed meats, and poultry with serum homocysteine concentrations after adjustment for demographic characteristics, lifestyle factors, and food intake.
Serum homocysteine concentrations were lower with greater intakes of whole grains (P for trend = 0.002), refined grains (P for trend = 0.02), and dairy foods (P for trend <0.001); were higher with greater intake of poultry (P for trend = 0.004); and were not related to intakes of fruit, vegetables, or red or processed meat. After additional adjustment for serum B vitamins, the relations of serum homocysteine with most food groups were attenuated.
These observational findings suggest a beneficial effect of whole-grain, refined-grain, and dairy products on serum homocysteine concentrations in an adolescent population.
Homocysteine; serum folate; cardiovascular disease; adolescents; food groups; whole grain
Declining levels of physical activity probably contribute to the increasing prevalence of overweight in US youth. In this study, the authors examined cross-sectional and longitudinal associations between physical activity and body composition in sixth- and eighth-grade girls. In 2003, girls were recruited from six US states as part of the Trial of Activity for Adolescent Girls. Physical activity was measured using 6 days of accelerometry, and percentage of body fat was calculated using an age- and ethnicity-specific prediction equation. Sixth-grade girls with an average of 12.8 minutes of moderate-to-vigorous physical activity (MVPA) per day (15th percentile) were 2.3 times (95% confidence interval: 1.52, 3.44) more likely to be overweight than girls with 34.7 minutes of MVPA per day (85th percentile), and their percent body fat was 2.64 percentage points greater (95% confidence interval: 1.79, 3.50). Longitudinal analyses showed that percent body fat increased 0.28 percentage points less in girls with a 6.2-minute increase in MVPA than in girls with a 4.5-minute decrease (85th and 15th percentiles of change). Associations between MVPA in sixth grade and incidence of overweight in eighth grade were not detected. More population-based research using objective physical activity and body composition measurements is needed to make evidence-based physical activity recommendations for US youth.
adipose tissue; adolescent; anthropometry; body composition; body mass index; exercise; growth; longitudinal studies