A randomized trial examining the effectiveness of switching from olanzapine, quetiapine, or risperidone to aripiprazole to reduce metabolic risk: comparison of antipsychotics for metabolic problems (CAMP).

OBJECTIVE: The authors conducted a multisite randomized controlled trial examining the strategy of switching from olanzapine, quetiapine, or risperidone to aripiprazole to ameliorate metabolic risk factors for cardiovascular disease. METHOD: Patients with schizophrenia or schizoaffective disorder with a body mass index ≥ 27 and non-high-density lipoprotein (non-HDL) cholesterol ≥ 130 mg/dl who were on a stable treatment dosage of olanzapine, quetiapine, or risperidone were randomly assigned to switch to ari-piprazole (N=109) for 24 weeks or stay on their current medication (N=106). All participants were enrolled in a behaviorally oriented diet and exercise program. Clinical raters were blinded to treatment assignment. The primary and key secondary outcomes were change in non-HDL cholesterol and efficacy failure, respectively. RESULTS: The prespecified primary analysis included 89 switchers and 98 stayers who had at least one postbaseline non-HDL cholesterol measurement. The least squares mean estimates of non-HDL cholesterol decreased more for the switch group than for the stay group (-20.2 mg/dl and -10.8 mg/dl, respectively). Switching was associated with larger weight reductions (least squares mean=2.9 kg) and a net reduction of serum triglycerides of 32.7 mg/dl. Twenty-two switchers (20.6%) and 18 stayers (17.0%) experienced protocol-defined efficacy failure. Forty-seven switchers (43.9%) and 26 stayers (24.5%) discontinued the assigned antipsychotic medication before 24 weeks. CONCLUSIONS: Switching to aripiprazole led to improvement of non-HDL cholesterol levels and other metabolic parameters. Rates of efficacy failure were similar between groups, but switching to aripiprazole was associated with a higher rate of treatment discontinuation. In the context of close clinical monitoring, switching from an antipsychotic with high metabolic risk to one with lower risk to improve metabolic parameters is an effective strategy.

Validity of social-cognitive measures for physical activity in middle-school girls.

OBJECTIVE: The factorial validity and measurement equivalence/invariance of scales used to measure social-cognitive correlates of physical activity among adolescent girls were examined. METHODS: Confirmatory factor analysis was applied to questionnaire responses obtained from a multi-ethnic sample (N = 4885) of middle-school girls from six regions of the United States. A cohort of 1893 girls completed the scales in both sixth and eighth grades, allowing longitudinal analysis. RESULTS: Theoretically and statistically sound models were developed for each scale, supporting the factorial validity of the scales in all groups. Multi-group and longitudinal invariance was confirmed across race/ethnicity groups, age within grade, BMI categories, and the 2-year period between grades. CONCLUSIONS: The scores from the scales provide valid assessments of social-cognitive variables that are putative mediators or moderators of change in physical activity. The revised scales can be used in observational studies of change or interventions designed to increase physical activity among girls during early adolescence.

Relationships among fitness, body composition, and physical activity.

PURPOSE: This study was designed to examine the associations of physical activity and body composition with cardiorespiratory fitness in eighth grade girls. METHODS: 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. 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. RESULTS: 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% (R) of the variation in physical fitness. Adding moderate-to-vigorous physical activity to the regression model increased the R 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. CONCLUSIONS: Physical activity, fat-free mass, and the interaction between fat-free mass and racial group are significantly associated with cardiorespiratory fitness in adolescent girls.

Girls' perception of physical environmental factors and transportation: reliability and association with physical activity and active transport to school.

BACKGROUND: Preliminary evidence suggests that the physical environment and transportation are associated with youth physical activity levels. Only a few studies have examined the association of physical environmental factors on walking and bicycling to school. Therefore, the purpose of this study was (1) to examine the test-retest reliability of a survey designed for youth to assess perceptions of physical environmental factors (e.g. safety, aesthetics, facilities near the home) and transportation, and (2) to describe the associations of these perceptions with both physical activity and active transport to school. METHODS: Test and retest surveys, administered a median of 12 days later, were conducted with 480 sixth- and eighth-grade girls in or near six U.S. communities. The instrument consisted of 24 questions on safety and aesthetics of the perceived environment and transportation and related facilities. Additionally, girls were asked if they were aware of 14 different recreational facilities offering structured and unstructured activities, and if so, whether they would visit these facilities and the ease with which they could access them. Test-retest reliability was determined using kappa coefficients, overall and separately by grade. Associations with physical activity and active transport to school were examined using mixed model logistic regression (n = 610), adjusting for grade, race/ethnicity, and site. RESULTS: Item-specific reliabilities for questions assessing perceived safety and aesthetics of the neighborhood ranged from 0.31 to 0.52. Reliabilities of items assessing awareness of and interest in going to the 14 recreational facilities ranged from 0.47 to 0.64. Reliabilities of items assessing transportation ranged from 0.34 to 0.58. Some items on girls' perceptions of perceived safety, aesthetics of the environment, facilities, and transportation were important correlates of physical activity and, in some cases, active transport to school. CONCLUSION: This study provides some psychometric support for the use of the questionnaire on physical environmental factors and transportation for studying physical activity and active transport to school among adolescent girls. Further work can continue to improve reliability of these self-report items and examine their association of these factors with objectively measured physical activity.

Associations of body size and composition with physical activity in adolescent girls.

PURPOSE: To examine whether components of body composition (size, fat mass, and fat-free mass) were related to physical activity. METHODS: A random sample of 60 eligible sixth grade girls at each of 36 schools (six schools per region and six regions in total sample); complete measurements on 1,553 girls. Physical activity was assessed over 6 d in each girl using an accelerometer, and body composition was assessed using a multiple regression equation using body mass index and triceps skinfold. Minutes of moderate-to-vigorous and vigorous physical activity were estimated from accelerometer counts per 30 s above threshold values determined from a previous study. RESULTS: Significant inverse relationships were found for all measures of body size and composition and all physical activity indices. The combination of fat and fat-free mass expressed as a weight and as an index (divided by height squared) along with race, SES, site, and school were most highly associated with physical activity in multiple regression analysis, accounting for 14-15% of the variance in physical activity. Fat mass was more closely related to moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) than fat-free mass with higher standardized regression coefficients. CONCLUSION: We conclude that both fat mass or fat mass index as well as fat-free mass or fat-free mass index make independent contributions in association with physical activity levels. These indices are recommended for future studies.

Predicting energy expenditure from accelerometry counts in adolescent girls.

PURPOSE: Calibration of accelerometer counts against oxygen consumption to predict energy expenditure has not been conducted in middle school girls. We concurrently assessed energy expenditure and accelerometer counts during physical activities on adolescent girls to develop an equation to predict energy expenditure. METHODS: Seventy-four girls aged 13-14 yr performed 10 activities while wearing an Actigraph accelerometer and a portable metabolic measurement unit (Cosmed K4b2). The activities were resting, watching television, playing a computer game, sweeping, walking 2.5 and 3.5 mph, performing step aerobics, shooting a basketball, climbing stairs, and running 5 mph. Height and weight were also assessed. Mixed-model regression was used to develop an equation to predict energy expenditure (EE) (kJ.min(-1)) from accelerometer counts. RESULTS: Age (mean [SD] = 14 yr [0.34]) and body-weight-adjusted correlations of accelerometer counts with EE (kJ.min(-1)) for individual activities ranged from -0.14 to 0.59. Higher intensity activities with vertical motion were best correlated. A regression model that explained 85% of the variance of EE was developed: [EE (kJ.min(-1)) = 7.6628 + 0.1462 [(Actigraph counts per minute - 3000)/100] + 0.2371 (body weight in kilograms) - 0.00216 [(Actigraph counts per minute - 3000)/100](2) + 0.004077 [((Actigraph counts per minute - 3000)/100) x (body weight in kilograms)]. The MCCC = 0.85, with a standard error of estimate = 5.61 kJ.min(-1). CONCLUSIONS: We developed a prediction equation for kilojoules per minute of energy expenditure from Actigraph accelerometer counts. This equation may be most useful for predicting energy expenditure in groups of adolescent girls over a period of time that will include activities of broad-ranging intensity, and may be useful to intervention researchers interested in objective measures of physical activity.

Comparison of two approaches to structured physical activity surveys for adolescents.

PURPOSE: To compare the test-retest reliability, convergent validity, and overall feasibility/ usability of activity-based (AB) and time-based (TB) approaches for obtaining self-reported moderate-to-vigorous physical activity (MVPA) from adolescents. METHODS: Adolescents (206 females and 114 males) completed two 3-d physical activity recalls using the AB and TB surveys, which contained identical lists of physical activities. The participants wore an MTI Actigraph accelerometer for the same period. RESULTS: The TB instrument took about 3 min longer to complete (P = 0.022). Overall 2-d test-retest correlations for MVPA were similar for the two surveys (r = 0.676 and 0.667), but the girls had higher reliability on the AB survey than the boys (girls: r = 0.713; boys: r = 0.568). The overall 3-d correlations for MVPA surveys and Actigraph counts varied by gender (girls: AB = 0.265 vs TB = 0.314; boys: AB = 0.340 vs TB = 0.277). Correlations for vigorous physical activity and Actigraph counts were higher for the AB than for the TB (r = 0.281 vs 0.162). As the interval between completing the surveys and the days being recalled increased, reliability and validity were lower, especially for the AB survey. CONCLUSION: For both genders, either approach is acceptable for obtaining MVPA information on a single day, but the TB approach appears to be slightly favored over the AB approach for obtaining multiple days of MVPA. A 3-d recall period appears to be too long for accurate recall of MVPA information from either instrument. For both genders, the surveys overestimated activity levels; thus, self-reports should be supplemented with objective data.

Intervention-related bias in reporting of food intake by fifth-grade children participating in an obesity prevention study.

Data collected as part of Pathways, a school-based trial for the primary prevention of obesity in American Indian children conducted between 1997 and 2000, were analyzed to examine possible intervention-related bias in food reporting. The authors hypothesized that children in the intervention schools may have systematically underreported their dietary intake relative to children in the control schools. Nutrient intake estimates for lunch derived from record-assisted 24-hour dietary recalls were compared with intake estimates from observed lunch intakes. Reported nutrient intakes were included in regression analyses as the dependent variables; observed intake, intervention condition, and age were included as independent variables. Results indicated that, among females, intervention condition was a significant predictor of reported energy, fat, and saturated fatty acid intakes. Independently of observed intake, reported lunch energy intake among females in the intervention schools was 66.8 calories lower than reported intake among females in the control schools (p = 0.03). These findings suggest that investigators should consider bias in reporting of dietary intake by intervention condition when conducting diet-focused intervention studies. Specifically, enhancing measures that rely on self-reports with objective measures of dietary intake would help investigators to evaluate whether differential reporting by treatment group has occurred.

Validity of self-reported dietary intake at school meals by American Indian children: the Pathways Study.

OBJECTIVE: To examine the validity of a modified diet record-assisted 24-hour recall in third-grade (8 to 10 years old) American Indian children. DESIGN: The children were trained to record their food intake using diet records, and then they recalled their 24-hour food intakes, using the diet records as memory prompts, during interviews by trained staff using the Minnesota Nutrition Data System (NDS; version 2.6, 1993, Food database version 8A, Nutrient database version 23; Nutrition Coordinating Center, University of Minnesota, Minneapolis). The modified method added training in portion size estimation. Direct observation of the children's intakes during school meals was used to validate the accuracy of their self-reported recalls. SUBJECTS: Eighty third-grade children recruited from schools from four of the American Indian Nations participating in the Pathways Study. Statistical analyses performed Pearson correlations were used for nutrient level data. A mixed regression model (PROC MIXED), with no other fixed effects and site as a random effect, was used to test the null hypothesis that the difference between recalled and observed intakes was zero (H(o): beta(o)=0). Food intake data were obtained from the Nutrition Data System Record Reports. RESULTS: There were no significant differences between recalled and observed energy intakes for the school meals combined or for either meal individually. Percentages of energy intake from fat, protein, and carbohydrate from recalls were not significantly different from those observed for the combined school meals. Pearson correlations for energy and energy-providing nutrients ranged from 0.52 to 0.86 for both meals, from 0.55 to 0.86 for school lunch, and from 0.61 to 0.86 for school breakfast. Agreement between recalled and observed food items was 75%. Children recalled 57% of food quantities within +/-10% of observed quantities. CONCLUSIONS: At the group level, American Indian children were able to accurately report the macronutrient proportions of their total energy intake, and their reporting of total energy intake (+13% of criterion) compares favorably with that of other ethnic groups of children of similar age. They were able to accurately recall the majority of foods that they were independently observed consuming during school meals.

Impact of the Pathways food service intervention on breakfast served in American-Indian schools.

BACKGROUND: Pathways was a multisite, multicomponent obesity prevention intervention for American-Indian schoolchildren. The goal of the school breakfast and lunch component was to reduce fat content of school meals to 30% or fewer calories from fat without compromising dietary quality. METHODS: An intensive 3-year intervention was implemented with school food service staff. Five consecutive days of school breakfast menu and recipe information was collected at 20 control and 19 intervention schools at four time intervals. Data were analyzed at nutrient and (in final year) food levels. RESULTS: Average total fat decreased in intervention schools from 16.0 grams at baseline to 13.6 grams by end of study, compared with 16.6 and 16.7 grams at baseline and final measurement in control schools (P<0.030). Percentage of calories from saturated fat were also significantly reduced from 12.0 to 8.9%, compared with 12.1 to 10.6% in control schools (P<0.014). There were no significant differences in total energy or other nutrients by treatment condition across four time points. Food-level data revealed a consistent pattern of more lower-fat items served in intervention schools compared to control schools. CONCLUSIONS: Pathways was successful in achieving its overall goal of reducing dietary fat in meals served for school breakfasts.