Recruitment and retention strategies and methods in the HEALTHY study.

HEALTHY was a 3-year middle school-based primary prevention trial to reduce modifiable risk factors for type 2 diabetes in youth. The study was conducted at seven centers across the country. This paper describes the recruitment and retention activities employed in the study. Schools and students were the focus of recruitment and retention. Each center was responsible for the recruitment of six schools; eligibility was based on ability to enroll a sufficient number of predominately minority and lower socioeconomic status students. Study staff met with district superintendents and school principals to verify the eligibility of schools, and to ascertain how appropriate the school would be for conducting the trial. Sixth grade students were recruited employing a variety of techniques; students and their parents did not know whether their school was randomized to the intervention or control arm. This cohort was followed through sixth, seventh and eighth grades. In the eighth grade, an additional sample of students who were not originally enrolled in the study was recruited in a similar manner to participate in data collection to allow for cross-sectional and dose-response secondary analyses. Parents signed informed consent forms and children signed informed assent forms, as per the needs of the local Institutional Review Board. Parents received a letter describing the results of the health screening for their children after data collection in sixth and eighth grades. Retention of schools and students was critical for the success of the study and was encouraged through the use of financial incentives and other strategies. To a large extent, student withdrawal due to out-migration (transfer and geographical relocation) was beyond the ability of the study to control. A multi-level approach that proactively addressed school and parent concerns was crucial for the success of recruitment and retention in the HEALTHY study.

Vigorous physical activity and cytokines in adolescents.

Habitual physical activity and chronic exercise may positively influence circulating cytokines in youth as in adults. The purpose of this study was to determine if adolescents reporting higher amounts of physical activity had a better cytokine profile independent of weight status. We compared the concentrations of cytokines in highly active (n = 60) and less active adolescents (n = 60) of different weight status [normal weight (BMI < 75th percentile), and overweight (BMI > 95th percentile)]. Vigorous physical activity (VPA) was obtained through a questionnaire and included activities with a MET level of > or =6. Adiponectin, resistin, TNF-alpha and IL-6 were measured in fasting plasma samples. Anovas indicated that girls with high VPA had higher adiponectin than girls with low VPA (P < 0.05), but similar resistin, TNF-alpha and IL-6 concentrations (P > 0.05). Boys with high VPA had only a trend to lower resistin than those with low VPA (P = 0.052). Differences between VPA groups were independent of weight status. In adolescents, higher amounts of accumulated habitual VPA may improve some cytokines, reducing the risk of inflammation associated with increased adiposity and insulin resistance. The effect of physical activity appears to be independent of weight status.

Relationship between caloric intake, body composition, and physical activity to leptin, thyroid hormones, and cortisol in adolescents.

This study examined the interrelationships between (1) the hormones leptin, TSH, free T3, and cortisol, and (2) caloric intake, body composition, and physical activity to these select hormones in adolescent boys and girls (n = 125, age = 13.4 +/- 0.9 years). The data indicate that adolescent boys and girls have some common hormonal interrelationships. However, certain hormonal relationships are not in agreement with reports for adults, suggesting that researchers should not assume that all endocrine findings in adults are automatically applicable to adolescents.

Cigarette use in adolescents: the Cardiovascular Health in Children and Youth Study.

Tobacco is the leading cause of preventable death in the United States, and its use is increasing in adolescents. To determine the interventions needed to prevent the initiation of smoking, it is important to know the factors related to tobacco use by adolescents. In this study the following factors related to cigarette use were examined: age, gender, ethnicity, self-esteem, physical activity, parental smoking, and socioeconomic status. Participants were 1,207 youth completing a written survey for the Cardiovascular Health in Children and Youth Study (CHIC II). Participants ranged in age from 10 to 15 years, with a mean age of 12.2 years; 64.2% were White, 24.0% Black, 5.8% Hispanic, and 6.0% other races. White and Hispanic youth and youth of other races had significantly higher rates of smoking than did Black youth. Significant risk factors for smoking were: higher grade in school, White race, and for girls only, lower self-esteem. In White youth those in the lowest socioeconomic status were most likely to be current and experimental smokers. Smoking was as common in girls as in boys at these ages. Multivariate analysis showed that neither physical activity nor parental smoking were significant predictors of smoking behaviors. These results suggest that smoking prevention programs for adolescents should specifically target White and Hispanic youth and those from families with low socioeconomic status. In addition, these interventions should include ways to increase self-esteem in girls.

A food frequency questionnaire for youth: psychometric analysis and summary of eating habits in adolescents.

PURPOSE: To examine the reliability and validity of the Eating Habits Questionnaire (EHQ) for adolescents and assess eating habits in the context of the Food Pyramid. METHODS: Subjects were 446 students (81.2% female) attending three middle schools (sixth to eighth grades). Over half (56.9%) were African-American. Reliability was assessed with 48-h and 2-week retests on two subsamples (n = 62) and validity was assessed by comparison with three 24-h recalls on an additional subsample (n = 24) and by factor analysis. The EHQ is a self-administered questionnaire consisting of 83 food items and questions assessing food habits and food preparation style. RESULTS: Internal validity, determined with factor analysis, found that 10 factors explained 81.3% of the variance in eating habits. Overall perfect agreement between food groups reported on the 24-h recall and on the EHQ was 56%. Internal consistency, assessed by Cronbach alpha, ranged from .60 to .89. Test-retest correlations were highest at 48 h, ranging from .46 to .85 for the 10 factors. Adolescents ate more servings of fats and sugars (11.2) and meats (6.0) and fewer breads (5.2) and vegetables (1.6) than recommended in Food Pyramid guidelines. In addition, subjects consumed more high-fat protein than low-fat protein servings. CONCLUSIONS: The EHQ is a valid and reliable food frequency questionnaire that has been tested with African-American and white adolescents in the Southeast. It showed that adolescents consume higher than recommended daily servings of fats, sweets, and meats and lower than recommended servings of vegetables and breads.

Leptin and obesity in mother-child pairs.

Defects in the leptin gene or the leptin receptor may be a genetic cause of obesity, but little is known about the familial associations of leptin and obesity. This study compared plasma leptin and measures of obesity in a sample of 248 subjects (124 mother-offspring pairs); 34% were African American and 66% were white. Youth were aged 12 to 16 years. Plasma leptin and body mass index (BMI) were higher in mothers than in their offspring and, among the offspring, higher in girls than boys, even after correcting for BMI or body fat. Racial differences in leptin were present in both mothers and youth when adjusting for percentage body fat but disappeared when adjusting for BMI. In univariate analyses of the associations between mothers and offspring, BMI was associated with leptin in all groups but was most strongly associated in white pairs and in mother-son pairs. In multiple regression analyses, when adjusting for BMI, significant predictors of leptin levelfor the boys and girls together were gender, BMI, and pubertal status of the offspring; in girls only BMI was significant (R2 = 0.72), and in boys the significant predictors were their BMI (R2 = 0.66) followed by their pubertal status (R2 = 0.06) and the leptin level of their mothers (R2 = 0.02). When adjusting for body fat, the predictors were the offspring's percentage bodyfat (R2 = 0. 67) and mother's leptin (R2 = 0.03), with similar results in gender-specific analyses. The authors conclude that leptin levels of youth are most closely associated with their degree of obesity or body fat; mother's leptin and, for boys only, pubertal status also play a small role. Although the small association between maternal leptin on leptin in their offspring could be due to either heredity or shared environment, the results of this study suggest that individual obesity and environmental factors are important predictors of leptin levels in children.

Changes in common activities of 3rd through 10th graders: the CHIC study.

PURPOSE: This study was a longitudinal examination of the change in both the activities done and the intensity of those activities from childhood to adolescence. METHODS: Common activities were assessed by questionnaire initially on 656 subjects from 21 elementary schools; 50.5% were female, 83.4% were Caucasian, 20.6% African-American, and 6.0% were other races. RESULTS: Girls more often reported sedentary activities overall. Weighted least squares analyses showed boys consistently reported more vigorous activities than girls (P < 0.0008). African-American girls reported fewer vigorous activities than Caucasian or other race girls (P = 0.027). Sedentary activities were more frequently reported with increasing age (X2 P < 0.001). The youngest African-American and Caucasian boys reported similar activity patterns. However, boys from other races reported more intense activities until sixth and seventh grades when African-American boys began reporting more sedentary activities than Caucasians or other races (P = 0.004). During sixth-eighth grades, Generalized Estimating Equations (GEE) models show that girls with more advanced pubertal status reported more sedentary activities than girls who were less developed (P < 0.0001). For high school girls, race was a marginally significant predictor (P = 0.05) of activity status. Neither race nor pubertal status were significant factors in activities chosen by middle school boys. However, for male high school students, Caucasians were more likely than African-Americans to report vigorous activities (P = 0.005). CONCLUSIONS: Variation in activities by race within gender suggests that establishing activity patterns in youth may be race-specific as well as gender-specific and must be accounted for in designing physical activity interventions. Also, pubertal maturation is a factor in activity choices in middle school girls.

The influence of physical activity, socioeconomic status, and ethnicity on the weight status of adolescents.

OBJECTIVE: This study examined the effects of physical activity, television viewing, video game play, socioeconomic status (SES), and ethnicity on body mass index (BMI). RESEARCH METHODS AND PROCEDURES: The sample was 2389 adolescents, 10 to 16 years of age (12.7 +/- 1.0 years); 1240 (52%) females and 1149 (48%) males; 77% white and 23% African American; from rural (77%) and urban (23%) settings. BMI and skinfolds were directly assessed. All other data were obtained from questionnaires. RESULTS: Watching television on non-school days was related to being overweight (p < 0.005). However, when BMI analyses were adjusted for ethnicity and SES, there were no significant effects of television viewing on BMI (p > 0.061). Increased hours of video game play enhanced the risk of being overweight for both genders when analyses were adjusted for ethnicity and SES (p < 0.019). In males, participation in as little as one high-intensity physical activity 3 to 5 days a week decreased the ethnic- and SES-adjusted relative risk of being overweight (RR = 0.646; CI: 0.427 to 0.977). For females, the ethnic- and SES-adjusted relative risk for being overweight was not significantly altered by physical activity. The logistic analyses further indicated the influence of low SES and African American ethnicity overshadowed any direct effect of television or videos. DISCUSSION: Because weight status of male adolescents appears to be more related to exercise habits than to television or video game habits, increased participation in high-intensity exercise appears to be important. For females, neither videos nor exercise habits appear to be related to risk of being overweight. However, ethnicity and SES may be important factors that can influence body weight status, while television viewing may be of some importance. Thus, programs to reduce obesity in female adolescent should focus their efforts in lower SES communities.

School-based research: problems of access and consent.

Public schools are enticing yet intimidating places to conduct research on children and adolescents. A public school provides a large potential subject pool; however, obtaining access to that subject pool can seem impossible with all the layers of permissions that must be obtained. If the study is federally funded, additional regulations apply. This article presents practical and proven approaches to obtaining access to and approval from schools or school systems, as well as parental consent, to conduct school-based research.

Effects of improvement in aerobic power on resting insulin and glucose concentrations in children.

In this study we determined the influence of improving aerobic power (VO(2max)) on basal plasma levels of insulin and glucose of 11- to 14-year-old children, while accounting for body fat, gender, pubertal status, and leisure-time physical activity (LTPA) levels. Blood samples were obtained from 349 children after an overnight fast and analyzed for plasma insulin and glucose. Height, mass, body mass index (BMI), and sum of skinfolds (Sigma triceps + subscapular sites) were measured. LTPA levels and pubertal status were estimated from questionnaires, and VO(2max) was predicted from a cycle ergometry test. Regardless of gender, insulin levels were significantly correlated (P = 0.0001) to BMI, skinfolds, pubertal stage, and predicted VO(2max), but were not related to LTPA levels. Fasting glucose levels were not correlated to measures of adiposity or exercise (LTPA score, VO(2max)) for females; however, BMI and skinfolds were correlated for males (P < 0.006). The children then took part in an 8-week aerobic exercise program. The 60 children whose VO(2max) improved (>/=3 ml x kg(-1) x min(-1)) had a greater reduction in circulating insulin than the 204 children whose VO(2max) did not increase -16 (41) vs -1 (63) pmol x l(-1); P = 0.028. The greatest change occurred in those children with the highest initial resting insulin levels. Plasma glucose levels were slightly reduced only in those children with the highest insulin levels whose VO(2max) improved (P < 0.0506). The results of this study indicate that in children, adiposity has the most significant influence on fasting insulin levels; however, increasing VO(2max) via exercise can lower insulin levels in those children with initially high levels of the hormone. In addition, LTPA does not appear to be associated with fasting insulin status, unless it is sufficient to increase VO(2max).

Smokeless tobacco use in adolescents: the Cardiovascular Health in Children (CHIC II) Study.

Smokeless tobacco has seen a resurgence of popularity among adolescents despite its association with oral cancer and altered cardiovascular function. This study examined age, gender, ethnicity, self-esteem, physical activity, parental smoking, and socioeconomic status as predictors of smokeless tobacco use among middle school children. Subjects included 1,211 youth (White (64%), Black (24%), Hispanic (6%), and Other (6%); age 12.2) participating in the Cardiovascular Health in Children and Youth (CHIC II) study. All data were collected by questionnaire. Factors related to ever using smokeless tobacco included older age (p < .001), being male (p < .001), lower self-esteem (p < .001), and having parents who currently (p = .02) or formerly (p = .05) smoked. Hispanics reported a higher current usage rate than other ethnic groups (p < .001). White youth in the lowest socioeconomic status were most likely to be experimental users (p = .007), while those in the high socioeconomic status were more likely to be current users (p = .006). Physical activity was not associated with smokeless tobacco use.

A public health vs a risk-based intervention to improve cardiovascular health in elementary school children: the Cardiovascular Health in Children Study.

OBJECTIVES: This study sought to determine the population effects of both classroom-based and risk-based interventions designed to reduce cardiovascular disease risk factors in children. METHODS: Elementary school children (n = 2109; age range: 7-12 years) were randomized by school to a classroom-based intervention for all third and fourth graders, a risk-based intervention only for those with 1 or more cardiovascular disease risk factors, or a control group. The 8-week interventions involved both knowledge--attitude and physical activity components. RESULTS: School-level analyses showed that physical activity in the risk-based group and posttest knowledge in the classroom-based group were significantly higher than in the control group. With regard to trends shown by individual-level analyses, cholesterol dropped more in the classroom-based than in the control group, and skinfold thickness decreased 2.9% in the classroom-based group and 3.2% in the risk-based group (as compared with a 1.1% increase in the control group). CONCLUSIONS: Both classroom-based and risk-based interventions had positive effects on physical activity and knowledge, with trends toward reduced body fat and cholesterol. However, the classroom-based approach was easier to implement and evidenced stronger results than the risk-based intervention.

Sudden death in school children: role of physical activities and meteorological conditions.

BACKGROUND: This current study is aimed at investigating the effect of physical activities and meteorological conditions on the sudden deaths of children without obvious causes at school. METHODS: The subjects are 76 victims of sudden death at school in the 12 years from 1983 to 1994 in Aichi Prefecture, Japan. The incidence of these sudden deaths is shown by month of the year, day of the week and hour of the day in relation to physical activities and meteorological factors. The analysis of Hayashi's quantitation type II was used for evaluation of the relationship between sudden deaths under the different physical conditions, such as sedentary (at rest or slow walking) or active (running, competitive sports or swimming) conditions, and meteorological or weather factors such as, season of the year, wind-chill factor, atmospheric pressure and relative humidity. RESULTS: Of 76 cases, 21 died suddenly under sedentary physical conditions and 55 under active conditions. The incidence of sudden death was highest from 10.00 to 11.00 h and on Thursday. Sudden death under sedentary conditions was associated with autumn and winter or with winter with high humidity and low atmospheric pressure. Sudden deaths during running were associated with spring with low humidity and high pressure and sudden deaths during competitive sports were associated with dry and cloudy weather. CONCLUSION: Sudden deaths in children at school may be associated with physical activities and meteorological conditions.

Cardiovascular disease risk factors and obesity of rural and urban elementary school children.

Previous studies on the influence of a rural/urban setting on the prevalence of cardiovascular disease risk factors in children have not sufficiently controlled for socioeconomic status, race, gender, and perhaps, may not have included a representative sample of rural and urban children. This study compared the cardiovascular disease risk factors and rate of obesity of children living in rural and urban settings. It also determined the magnitude of the effect of the rural/urban setting on cardiovascular disease risk factors and obesity when controlling for race, socioeconomic status, and gender. The subjects were 2,113 third- and fourth-grade children; 962 from an urban setting and 1,151 from a rural setting. Height, weight, skinfolds, resting blood pressure, and total cholesterol levels were measured. Aerobic power (pVO2max) was estimated from cycle ergometry. Physical activity and smoking history were obtained from a questionnaire. Clustering analyses using adjustment for sample error indicated that total cholesterol, blood pressure, smoking, and physical activity levels of rural and urban children were not different (P > 0.10); however, body mass index and sum of skinfolds was greater for rural youth (P < 0.004). Logistic regression indicated that rural children had a 54.7 percent increased risk of obesity (P = 0.0001). This study's results indicate that, in children, a rural setting is associated with obesity, but not with the major risk factors associated with cardiovascular disease.

Predicting aerobic power in children. A comparison of two methods.

OBJECTIVE: To compare the accuracy of two equations for predicting VO2max of children using submaximal cycle ergometry. EXPERIMENTAL DESIGN: Repeated measures comparing treadmill measured maximal aerobic power (VO2max) with two methods of predicting VO2max using cycle ergometry testing. PARTICIPANTS: Thirty-three children (15 boys and 18 girls) aged 7-13 years served as subjects. MEASURES: Each child completed a treadmill graded exercise test (GXT) to volitional fatigue to assess VO2max. Each child also completed a progressive 9-min, three-stage, submaximal cycle ergometer test. Heart rates obtained during the last minute of each stage of the ergometer test were used to predict VO2max. Predictions were based on a gender-specific modification of the PWC170 (PWCGS) and a modification of the PWC195 using a 1.17 correction factor and an age and gender-adjusted estimate of resting metabolic rate. RESULTS: The correlations between both submaximal tests and the GXT were significant (p < 0.001); however, the correlation between the GXT and the PWC195 equation (r = 0.807) was higher than the correlation between the GXT and the PWCGS equation (r = 0.658). Analysis indicated that the PWCGS equation significantly underestimated the VO2max compared to either the GXT or PWC195 (GXT = 45.0 +/- 7.1, PWC195 = 44.7 +/- 6.2, PWCGS = 42.7 +/- 5.8 ml/kg/min; p < 0.01). CONCLUSIONS: These results suggest that although the gender-specific PWCGS method is easier to compute and may be acceptable, the modified PWC195 method is a more accurate estimate of VO2max in children.

Smoking initiation in youth: the roles of gender, race, socioeconomics, and developmental status.

PURPOSE: To describe smoking initiation, and to investigate factors that predict the early initiation of smoking in schoolchildren using a longitudinal approach. METHODS: A prospective study of smoking habits of children from the third and fourth grades through the eighth and ninth grades. The initial study population was 1970; 79.8% were white and 20.2% were African-American. Children were classified as "nonsmokers," "experimental smokers," or "current smokers" at five time points over 6 years. Multivariate regression models examined relationships of demographic and developmental factors with smoking initiation. RESULTS: Experimental smoking increased from 4% at Grades 3-4 to 42% at Grades 8-9, and current smoking prevalence rose from 0.4% to 9% over the same period. The mean age of initiation of smoking was 12.3 years. Smoking initiation (experimental smoking) was significantly different by racial group, socioeconomic status (SES), and pubertal development. White children and those of low SES were more likely to be experimental smokers, and also started earlier than African-American children and children of high SES. Once they started, white children advanced more rapidly to become current smokers. Boys had a higher prevalence of experimental smoking than girls at all time points. Children in rural areas were more likely than urban children to start smoking after age 12 years. Children who were at a higher pubertal stage than their peers were also more likely to experiment with smoking. CONCLUSIONS: Race, SES, and pubertal stage are important predictors of initiation of smoking in schoolchildren. This study indicates a need for smoking prevention classes in elementary and middle school, especially in areas with large numbers of white and low-SES youth. Also, smoking cessation programs, as well as smoking prevention classes, would be useful for middle school and high school students.

Is physical activity or aerobic power more influential on reducing cardiovascular disease risk factors?

PURPOSE: This study determined the relationship between aerobic power (VO2max), physical activity (PA), and cardiovascular disease (CVD) risk factors. The study also determined how increased VO2max and increased PA levels influence CVD risk factors of 576 low-fit adults (VO2max < 30 mL.kg-1.min-1). METHODS: PA (Baeke questionnaire) and VO2max (submaximal cycle test) of 1664 law enforcement trainees were evaluated with respect to the CVD risk factors of total cholesterol, blood pressure (BP) [BP], smoking, and obesity using separate logistic regression, adjusting for age, gender, and the other major CVD risk factors. RESULTS: Compared with the lowest tertile of VO2max, the highest tertile had a reduced relative risk (RR) for elevated cholesterol (RR, 0.56; CI, 0.36-0.43), BP (RR, 0.32; CI, 0.15-0.62) and obesity (RR, 0.09; CI, 0.06-0.12). The middle tertile of VO2max compared with the lowest had reduced RR for elevated diastolic BP (RR, 0.44; CI, 0.23-0.66) and obesity (RR: 0.38; CI 0.28-0.50). High PA tertile, compared with low PA tertile, only had lower RR for high systolic BP (RR, 0.48; CI, 0.23-0.95). Compared with the low PA tertile, moderate or high PA had no reduction in any of the RR (P > 0.05). Participation in a 9-wk exercise program by low-fit individuals resulted in a 9% increase in PA levels (P < 0.02); however, only those subjects who increased VO2max (> 3 mL.kg-1.min-1; N = 345) had a reduction in RR for high cholesterol (RR: 0.62; CI 0.42-0.92) and systolic BP (RR: 0.57; CI 0.40-0.80). No reduction in RR were noted for diastolic BP or obesity. CONCLUSIONS: Aerobic power appears to have more of an influence on CVD risk factors than PA levels. Further, in low-fit persons, it appears that PA resulting in an increased aerobic power is associated with a reduction in CVD risk factors of cholesterol and BP in as little as 9 wk.

School-based interventions improve heart health in children with multiple cardiovascular disease risk factors.

OBJECTIVE: To determine the immediate effects of two types of elementary school-based interventions on children with multiple cardiovascular disease (CVD) risk factors. DESIGN: Randomized, controlled field trial. SETTING: Conducted in 18 randomly selected elementary schools across North Carolina. STUDY PARTICIPANTS: Four hundred twenty-two children age 9 +/- 0.8 years with at least two risk factors at baseline: low aerobic power and either high serum cholesterol or obesity. INTERVENTION: Both 8-week interventions consisted of a knowledge and attitude program and an adaptation of physical education. The classroom-based intervention was given by regular teachers to all children in the 3rd and 4th grades. The risk-based intervention was given in small groups only to children with identified risk factors. Children in the control group received usual teaching and physical education. OUTCOME MEASURES: The primary outcome measure was cholesterol; additional measures were blood pressure, body mass index, body fat, eating and activity habits, and health knowledge. RESULTS: Both interventions produced large reductions in cholesterol (-10.1 mg/dL and -11.7 mg/dL) compared with a small drop (-2.3 mg/dL) in the controls. There was a trend for systolic blood pressure to increase less in both intervention groups than in the controls. Both intervention groups had a small reduction in body fat and higher health knowledge than the control group. CONCLUSIONS: Both brief interventions can improve the CVD risk profile of children with multiple risk factors. The classroom-based approach was easier to implement and used fewer resources. This population approach should be considered as one means of early primary prevention of CVD.

Comparison of a computerized physical activity recall with a triaxial motion sensor in middle-school youth.

PURPOSE: To develop and test a computerized activity recall (CAR) for capturing activity and energy expenditure (EE) in youth and to further our understanding of the use of the three-dimensional accelerometer (Tritrac) for studying activity and EE. METHODS: Forty-five students (25 girls and 20 boys) in grade 6-8, completed 5 consecutive days of the CAR and were randomly assigned to wear the Tritrac during 1 day in which they also completed the CAR. Twenty-two subjects also repeated 5 d of the CAR and 1 d of Tritrac monitoring 1-2 wk later. RESULTS: The correlation between CAR and Tritrac for total EE was significant (r = 0.510, P = 0.0003). However, the total EE computed from the Tritrac was significantly greater than the CAR (1941 +/- 273 kcal vs 1576 +/- 343 kcal (8.14 +/- 1.14 vs 6.60 +/- 1.44 MJ); P < 0.001). The EE of activities was similar for the Tritrac and CAR, approximately 670 kcal (2.80 MJ), suggesting that the difference between the two methods was their estimates of resting EE. Comparison of the CAR and Tritrac for classifying active and inactive subjects indicated that both methods similarly classified 35 of the 45 subjects or 78% (P = 0.0038). Although significant, the Kappa statistic (kappa = 0.398) indicated a low-level of agreement between methods. The Tritrac indicated 50.4 +/- 29.2 min.d-1 of activities of > or = 3 METs, whereas the CAR indicated 76.7 +/- 71.9 min.d-1 (P = 0.02). The week 1 vs 2 test-retest correlation was 0.0485 (P = 0.022) for the Tritrac and 0.820 (P = 0.0001) for the CAR. CONCLUSIONS: It appears that both methods have acceptable reliability. However, the validity of each method to measure total and activity EE remains unclear, as the Tritrac appears to overestimate resting energy expenditure, whereas the CAR overestimates total minutes of activity.

Cardiovascular risk factors and socioeconomic status in African American and Caucasian women.

Self-reported cardiovascular risk factors of obesity, physical inactivity, and smoking in African American and Caucasian women in North Carolina were compared, controlling for socioeconomic status (SES). Participants were 1,945 women aged 23 to 53 years; 20.1% African American and 79.9% Caucasian. Of the African American women, 38.8% were obese, 51.7% were inactive, and 31.2% smoked; of the Caucasians, 19.9% were obese, 31.2% were inactive, and 33.8% smoked. SES differed significantly by race (p < .001). Low and middle SES African American women were much more likely than high SES African Americans to be obese, inactive, and smokers. Among Caucasian women, those with low SES had the greatest prevalence for all three risk factors. After controlling for income and education, African American women were more than twice as likely as Caucasian women to be obese and to be inactive, but were only half as likely to smoke.