Ankle brachial index screening in asymptomatic older adults.

BACKGROUND: Screening for peripheral arterial disease (PAD) by measuring ankle brachial index (ABI) in asymptomatic older adults is currently recommended to improve cardiovascular disease risk assessment and establish early treatment, but it is not clear if the strategy is useful in all populations. We examined the prevalence and independent predictors of an abnormal ABI (<0.90), in an asymptomatic sample of 1,017 adults, 60 to 69 years old, enrolled in the ADVANCE study. METHODS: Baseline data collected between December 2001 and January 2004 among the healthy older controls enrolled in ADVANCE was examined. Frequency distributions and prevalence estimates of an abnormal ABI were calculated, using both standard and modified definitions of ABI. Stepwise logistic regression was used to examine independent predictors of ABI <0.90. Signal detection analysis using recursive partitioning was employed to explore potential demographic and clinical variables related to ABI <0.90. RESULTS: The prevalence of ABI <0.90 was 2% when using the standard definition and 5% when using a modified definition. ABI prevalence did not differ by gender (P > .05). Compared with subjects who had a normal ABI (0.90-1.39), subjects with an ABI <0.90 were more likely to currently smoke, be physically inactive, have a coronary artery calcium score >10, and an FRS >20% (P ≤ .02). Independent predictors of ABI <0.90 when using the standard definition included currently smoking, physical inactivity, and body mass index >30 (all P values ≤.03), and when using the modified definition included currently smoking, physical inactivity, and hypertension (all P values ≤.04). Currently, smoking was the only significant variable for ABI <0.90 derived through recursive partitioning (P = .02), and indicated that prevalence of ABI <0.90 was 1.5% for nonsmokers, while it was 6.6% for current smokers. CONCLUSIONS: ABI screening in generally healthy individuals 60 to 69 years old may result in lower prevalence rates of a positive result than estimates based on studies in clinical populations. The modified definition for calculating ABI captured more asymptomatic adults with suspected peripheral arterial disease. More evaluation of the appropriate role of ABI screening in unselected populations is needed before routine screening is implemented.

Racial variation in lipoprotein-associated phospholipase A2 in older adults.

BACKGROUND: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a predictor of cardiovascular events that has been shown to vary with race. The objective of this study was to examine factors associated with this racial variation. METHODS: We measured Lp-PLA2 mass and activity in 714 healthy older adults with no clinical coronary heart disease and not taking dyslipidemia medication. We evaluated the association between race and Lp-PLA2 mass and activity levels after adjustment for various covariates using multivariable linear regression. These covariates included age, sex, diabetes, hypertension, body mass index, lipid measurements, C-reactive protein, smoking status, physical activity, diet, income, and education level. We further examined genetic covariates that included three single nucleotide polymorphisms shown to be associated with Lp-PLA2 activity levels. RESULTS: The mean age was 66 years. Whites had the highest Lp-PLA2 mass and activity levels, followed by Hispanics and Asians, and then African-Americans; in age and sex adjusted analyses, these differences were significant for each non-White race as compared to Whites (p < 0.0001). For example, African-Americans were predicted to have a 55.0 ng/ml lower Lp-PLA2 mass and 24.7 nmol/ml-min lower activity, compared with Whites, independent of age and sex (p < 0.0001). After adjustment for all covariates, race remained significantly correlated with Lp-PLA2 mass and activity levels (p < 0.001) with African-Americans having 44.8 ng/ml lower Lp-PLA2 mass and 17.3 nmol/ml-min lower activity compared with Whites (p < 0.0001). CONCLUSION: Biological, lifestyle, demographic, and select genetic factors do not appear to explain variations in Lp-PLA2 mass and activity levels between Whites and non-Whites, suggesting that Lp-PLA2 mass and activity levels may need to be interpreted differently for various races.

Distribution of asymmetric dimethylarginine among 980 healthy, older adults of different ethnicities.

BACKGROUND: Endothelium-derived nitric oxide plays a crucial role in the regulation of vascular tone and the development of cardiovascular disease. The endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) has emerged as a novel cardiovascular risk factor. ADMA appears to be an independent predictor for cardiovascular and overall mortality. However, the majority of studies investigating the clinical role of ADMA were performed in European study populations with few individuals of other ethnicities. METHODS: We performed a cross-sectional study of 980 healthy, older (age 60-72 years) individuals of different ethnicities living in the San Francisco Bay area and analyzed ADMA plasma concentrations and their relationship to other cardiovascular risk factors. Plasma ADMA concentrations were measured using a recently developed, highly sensitive ELISA. RESULTS: In our entire sample, we were able to define a reference interval for ADMA plasma concentrations of 0.47 (90% CI 0.46-0.48) mumol/L to 0.85 (0.84-0.89) mumol/L. The mean ADMA concentration was 0.63 (SD 0.11) mumol/L (median 0.61 mumol/L). Mean ADMA concentrations were significantly lower in African Americans (0.60 mumol/L; P < 0.01) and mixed non-Hispanics (0.60 mumol/L; P < 0.05) compared with whites (0.63 mumol/L). ADMA was positively correlated with cystatin-C in both men (rho = 0.29) and women (rho = 0.37), and median plasma ADMA concentrations increased across cystatin-C quintiles. CONCLUSIONS: ADMA varies nearly 2-fold across a healthy sample of older men and women, correlates with age, body mass index, and renal function, and is different across ethnic groups. Additional studies in a wider age range and including larger ethnic subgroups would be useful.

Insulin resistance independently predicts the progression of coronary artery calcification.

BACKGROUND: Change in coronary artery calcification is a surrogate marker of subclinical coronary artery disease (CAD). In the only large prospective study, CAD risk factors predicted progression of coronary artery calcium (CAC). METHODS: We measured CAC at enrollment and after 24 months in a community-based sample of 869 healthy adults aged 60 to 72 years who were free of clinical CAD. We assessed predictors of the progression of CAC using univariate and multivariate models after square root transformation of the Agatston scores. Predictors tested included age, sex, race/ethnicity, smoking status, body mass index, family history of CAD, C-reactive protein and several measures of diabetes, insulin levels, blood pressure, and lipids. RESULTS: The mean age of the cohort was 66 years, and 62% were male. The median CAC at entry was 38.6 Agatston units and increased to 53.3 Agatston units over 24 months (P < .01). The CAC progression was associated with white race, diabetes, dyslipidemia, hypertension, lower diastolic blood pressure, and higher pulse pressure. After controlling for these variables, higher fasting insulin levels independently predicted CAC progression. CONCLUSIONS: Insulin resistance, in addition to the traditional cardiac risk factors, independently predicts progression of CAC in a community-based population without clinical CAD.

Stanford GEMS phase 2 obesity prevention trial for low-income African-American girls: design and sample baseline characteristics.

OBJECTIVE: African-American girls and women are at high risk of obesity and its associated morbidities. Few studies have tested obesity prevention strategies specifically designed for African-American girls. This report describes the design and baseline findings of the Stanford GEMS (Girls health Enrichment Multi-site Studies) trial to test the effect of a two-year community- and family-based intervention to reduce weight gain in low-income, pre-adolescent African-American girls. DESIGN: Randomized controlled trial with measurements scheduled in girls' homes at baseline, 6, 12, 18 and 24 month post-randomization. SETTING: Low-income areas of Oakland, CA. PARTICIPANTS: Eight, nine and ten year old African-American girls and their parents/caregivers. INTERVENTIONS: Girls are randomized to a culturally-tailored after-school dance program and a home/family-based intervention to reduce screen media use versus an information-based community health education Active-Placebo Comparison intervention. Interventions last for 2 years for each participant. MAIN OUTCOME MEASURE: Change in body mass index over the two-year study. RESULTS: Recruitment and enrollment successfully produced a predominately low-socioeconomic status sample. Two-hundred sixty one (261) families were randomized. One girl per family is randomly chosen for the analysis sample. Randomization produced comparable experimental groups with only a few statistically significant differences. The sample had a mean body mass index (BMI) at the 74 th percentile on the 2000 CDC BMI reference, and one-third of the analysis sample had a BMI at the 95th percentile or above. Average fasting total cholesterol and LDL cholesterol were above NCEP thresholds for borderline high classifications. Girls averaged low levels of moderate to vigorous physical activity, more than 3 h per day of screen media use, and diets high in energy from fat. CONCLUSIONS: The Stanford GEMS trial is testing the benefits of culturally-tailored after-school dance and screen-time reduction interventions for obesity prevention in low-income, pre-adolescent African-American girls.

Ethnic differences in coronary artery calcium in a healthy cohort aged 60 to 69 years.

Measurement of coronary artery calcium (CAC) has been proposed as a screening tool, but CAC levels may differ according to race and gender. Racial/ethnic and gender distributions of CAC were examined in a randomly selected cohort of 60- to 69-year-old healthy subjects. Demographic, race/ethnicity (R/E), and clinical characteristics and assessment of CAC were collected. There were 723 white/European, 105 African-American, 73 Hispanic, and 67 East Asian subjects (597 men, 369 women) included in this analysis. Men had a significantly higher prevalence of any CAC (score>10) than women (76% vs 41%; p<0.0001). For men, the unadjusted odds of having any CAC was 2.2 (95% confidence interval [CI] 1.3 to 3.8) for whites compared with African-Americans. For women, CAC scores were not significantly different across ethnic groups. After adjustment for coronary risk factors, African-American and East Asian R/E remained associated with a lower prevalence of CAC in men (adjusted odds ratios [ORs] 0.33 and 0.47, respectively), as well as older age (OR 1.2, 95% CI 1.1 to 1.3), known hyperlipidemia (OR 1.7, 95% CI 1.1 to 2.7), and history of hypertension (OR 2.2, 95% CI 1.4 to 3.3). In women, Asian R/E (OR 2.5, 95% CI 1.1 to 5.7), history of smoking (adjusted OR 2.8, 95% CI 1.3 to 6.1), and known hyperlipidemia (adjusted OR 2.0, 95% CI 1.3 to 3.1) were associated with a higher prevalence of CAC independent of other risk factors. In conclusion, our data indicate that the presence of CAC varied significantly across selected race/ethnic groups independent of traditional cardiovascular risk factors.

Extended treatment for cigarette smoking cessation: a randomized control trial.

AIM: To test the potential benefit of extending cognitive-behavioral therapy (CBT) relative to not extending CBT on long-term abstinence from smoking. DESIGN: Two-group parallel randomized controlled trial. Patients were randomized to receive non-extended CBT (n = 111) or extended CBT (n = 112) following a 26-week open-label treatment. SETTING: Community clinic in the United States. PARTICIPANTS: A total of 219 smokers (mean age: 43 years; mean cigarettes/day: 18). INTERVENTION: All participants received 10 weeks of combined CBT + bupropion sustained release (bupropion SR) + nicotine patch and were continued on CBT and either no medications if abstinent, continued bupropion + nicotine replacement therapy (NRT) if increased craving or depression scores, or varenicline if still smoking at 10 weeks. Half the participants were randomized at 26 weeks to extended CBT (E-CBT) to week 48 and half to non-extended CBT (no additional CBT sessions). MEASUREMENTS: The primary outcome was expired CO-confirmed, 7-day point-prevalence (PP) at 52- and 104-week follow-up. Analyses were based on intention-to-treat. FINDINGS: PP abstinence rates at the 52-week follow-up were comparable across non-extended CBT (40%) and E-CBT (39%) groups [odds ratio (OR) = 0.99; 95% confidence interval (CI) = 0.55, 1.78]. A similar pattern was observed across non-extended CBT (39%) and E-CBT (33%) groups at the 104-week follow-up (OR = 0.79; 95% CI= 0.44, 1.40). CONCLUSION: Prolonging cognitive-behavioral therapy from 26 to 48 weeks does not appear to improve long-term abstinence from smoking.

Do Mexican-American mothers' food-related parenting practices influence their children's weight and dietary intake?

Food-related parenting attitudes are thought to influence children's dietary intake and weight. The objective of this study was to examine the associations between mothers' reports of food-related parenting and children's dietary intake and body mass index (BMI). A sample of 108 Mexican-American fifth-grade children and their mothers were surveyed. Children's height, weight, and three 24-hour dietary recalls were collected. Mothers reported household food insecurity status and food-related parenting attitudes. Correlational analyses were calculated among dietary intake variables, children's BMI percentiles, and food-parenting behaviors. Mothers' pressure on their children to eat was inversely correlated with children's BMI. In food-insecure families, attitudes toward making healthful foods available were inversely associated with children's daily energy intake and BMI. In contrast, in food-secure families, attitudes about making healthful foods available were positively associated with children's fruit intake and percentage energy from fat, and parental modeling of healthful food behaviors was inversely associated with the energy density. In our sample of Mexican-American families, mothers' food-related parenting was associated with their children's weight and dietary intake. These associations differed in food-secure and food-insecure households. Overall, pressure to eat was highly associated with children's weight, but the temporal nature of these relationships cannot be discerned.

Household food security and nutritional status of Hispanic children in the fifth grade.

BACKGROUND: Food insecurity is a critical variable for understanding the nutritional status of low-income populations. However, limited research is available on the relation between household food insecurity and children's nutritional status. OBJECTIVE: Our objective was to examine the relations among household food insecurity, household food supplies, and school-age children's dietary intakes and body mass indexes (BMIs). DESIGN: A sample of 124 predominantly Hispanic, fifth-grade children and their mothers were surveyed as part of a school-based obesity-prevention program. Data on the children's weights and heights were collected and three 24-h dietary recalls were conducted. The mothers provided reports of household food insecurity and household food supplies. RESULTS: Food insecurity was negatively associated with the children's BMIs and household food supplies but not with the children's food intakes. However, a secondary analysis showed that as payday approached, children from the most food-insecure households had significant decreases in energy intakes and meat consumption. CONCLUSIONS: This is one of the first studies to report a significant association between food insecurity and children's nutritional status. The ages and sex-adjusted BMIs of the food-insecure children were lower than those of the food-secure children but were still within the normal range. The lower BMIs in the food-insecure children may have been due to short-term, yet periodic food restrictions that resulted as household food supplies diminished before payday. Future research is needed to assess the physiologic and psychological effects of periodic food restriction on children's health.

Children's food consumption during television viewing.

BACKGROUND: Television viewing is associated with childhood obesity. Eating during viewing and eating highly advertised foods are 2 of the hypothesized mechanisms through which television is thought to affect children's weight. OBJECTIVES: Our objectives were to describe the amounts and types of foods that children consume while watching television, compare those types with the types consumed at other times of the day, and examine the associations between children's body mass index (BMI) and the amounts and types of foods consumed during television viewing. DESIGN: Data were collected from 2 samples. The first sample consisted of ethnically diverse third-grade children, and the second consisted predominantly of Latino fifth-grade children. Three nonconsecutive 24-h dietary recalls were collected from each child. For each eating episode reported, children were asked whether they had been watching television. Height and weight were measured by using standard methods and were used to calculate BMI. RESULTS: On weekdays and weekend days, 17-18% and approximately 26% of total daily energy, respectively, were consumed during television viewing in the 2 samples. Although the fat content of the foods consumed during television viewing did not differ significantly from that of the foods consumed with the television off, less soda, fast food, fruit, and vegetables were consumed with the television on. The amount of food consumed during television viewing was not associated with children's BMI, but in the third-grade sample, the fat content of foods consumed during television viewing was associated with BMI. CONCLUSIONS: A significant proportion of children's daily energy intake is consumed during television viewing, and the consumption of high-fat foods on weekends may be associated with BMI in younger children.

Do men outperform women in smoking cessation trials? Maybe, but not by much.

Using data from 4 smoking cessation trials conducted from 1988 to 2000, the authors investigated whether men are more successful than women in quitting smoking. Odds ratios indicated that the abstinence rates were not significantly different for men and women. Thus, there may be little value to diverting research funds from efforts to develop more effective treatments for both men and women to efforts to explain a very small gender effect associated with existing treatments. However, it may be appropriate to make gender comparisons for new therapies for nicotine dependence. The authors recommend against analyses of gender differences in studies that do not account for gender in their research designs.

Onset of major depression during treatment for nicotine dependence.

We monitored the emergence of major depression (MDD) during treatment for nicotine dependence among 224 smokers. MDD was assessed on three occasions during the course of treatment with the mood disorders portion of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (SCID), fourth edition (DSM-IV). Out of 224 participants, 20% had suffered a past episode of MDD, 18% of males and 22% of females. Four percent (n=10) experienced onset of MDD during the course of the study, four males and six females. Only 2 of the 10 cases managed to achieve abstinence at end of treatment. Those who reported large increases in depression symptoms between baseline and end of treatment (Week 10) were less likely to be abstinent at 26-week follow-up. The evidence indicates that those who treat nicotine dependence must be prepared to monitor and respond to the emergence of depression associated with treatment.

Dance and reducing television viewing to prevent weight gain in African-American girls: the Stanford GEMS pilot study.

OBJECTIVE: To test the feasibility, acceptability, and potential efficacy of after-school dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, among African-American girls. DESIGN: Twelve-week, 2-arm parallel group, randomized controlled trial. SETTING: Low-income neighborhoods. PARTICIPANTS: Sixty-one 8-10-year-old African-American girls and their parents/guardians. INTERVENTIONS: The treatment intervention consisted of after-school dance classes at 3 community centers, and a 5-lesson intervention, delivered in participants' homes, and designed to reduce television, videotape, and video game use. The active control intervention consisted of disseminating newsletters and delivering health education lectures. MAIN OUTCOME MEASURES: Implementation and process measures, body mass index, waist circumference, physical activity measured by accelerometry, self-reported media use, and meals eaten with TV. RESULTS: Recruitment and retention goals were exceeded. High rates of participation were achieved for assessments and intervention activities, except where transportation was lacking. All interventions received high satisfaction ratings. At follow up, girls in the treatment group, as compared to the control group, exhibited trends toward lower body mass index (adjusted difference = -.32 kg/m2, 95% confidence interval [CI] -.77, .12; Cohen's d = .38 standard deviation units) and waist circumference (adjusted difference = -.63 cm, 95% CI -1.92, .67; d = .25); increased after-school physical activity (adjusted difference = 55.1 counts/minute, 95% CI -115.6, 225.8; d = .21); and reduced television, videotape, and video game use (adjusted difference = -4.96 hours/week, 95% CI -11.41, 1.49; d = .40). The treatment group reported significantly reduced household television viewing (d = .73, P = .007) and fewer dinners eaten while watching TV (adjusted difference = -1.60 meals/week, 95% CI -2.99, -.21; d = .59; P = .03). Treatment group girls also reported less concern about weight (d = .60; P = .03), and a trend toward improved school grades (d = .51; P = .07). CONCLUSIONS: This study confirmed the feasibility, acceptability, and potential efficacy of using dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, in African-American girls.

Phlebitis in amiodarone administration: incidence, contributing factors, and clinical implications.

BACKGROUND: Intravenous amiodarone is an important treatment for arrhythmias, but peripheral infusion is associated with direct irritation of vessel walls and phlebitis rates of 8% to 55%. Objectives To determine the incidence and factors contributing to the development of amiodarone-induced phlebitis in the coronary care unit in an academic medical center and to refine the current practice protocol. METHODS: Medical records from all adult patients during an 18-month period who received intravenous amiodarone while in the critical care unit were reviewed retrospectively. Route of administration, location, concentration, and duration of amiodarone therapy and factors associated with occurrence of phlebitis were examined. Descriptive statistics and regression methods were used to identify incidence and phlebitis factors. RESULTS: In the final sample of 105 patients, incidence of phlebitis was 40%, with a 50% recurrence rate. All cases of phlebitis occurred in patients given a total dose of 3 g via a peripheral catheter, and one-quarter of these cases (n = 10) developed at dosages less than 1 g. Pain, redness, and warmth were the most common indications of phlebitis. Total dosage given via a peripheral catheter, duration of infusion, and number of catheters were significantly associated with phlebitis. CONCLUSIONS: Amiodarone-induced phlebitis occurred in 40% of this sample at higher drug dosages. A new practice protocol resulted from this study. An outcome study is in progress.

Physical activity in older subjects is associated with increased coronary vasodilation: the ADVANCE study.

OBJECTIVES: We investigated the association between physical activity and coronary vasodilation to nitroglycerin (NTG) in the ADVANCE (Atherosclerotic Disease, Vascular Function, and Genetic Epidemiology) cohort of older healthy subjects. BACKGROUND: Physical activity may exert its beneficial effects by augmenting coronary responsiveness to nitric oxide. The relationship between physical activity and coronary vasodilatory response to NTG, an exogenous nitric oxide donor, has not been studied in a community-based population with typical activity levels. METHODS: In 212 older adults (ages 60 to 72 years) without cardiovascular disease, we measured the coronary vasodilatory response to NTG using magnetic resonance angiography and physical activity using the Stanford Seven-Day Physical Activity Recall Questionnaire. The primary predictor measure was total physical activity (kcal/kg/day). The primary outcome measure was coronary vasodilatory response (percent increase of cross-sectional area post-NTG). RESULTS: Coronary vasodilation was 27.6% in more active subjects (>35 kcal/kg/day, e.g., 1 h of walking per day) compared to 18.9% in less active subjects (p=0.03). Regression analysis showed a significant positive correlation between coronary vasodilation and physical activity (p=0.003), with a slope (beta) of 1.2% per kcal/kg/day. This finding remained significant after adjustment for cardiac risk factors, coronary calcium, the use of vasoactive or statin medications, and analysis of physical activity by quintiles (p < 0.05). Coronary vasodilation was also associated with physical activity intensity (p = 0.03). CONCLUSIONS: In an asymptomatic, community-based cohort of older adults, increased coronary vasodilatory response was independently associated with greater physical activity, supporting the benefits of exercise on the order of 1 h of walking per day.

Validation of the Stanford Brief Activity Survey: examining psychological factors and physical activity levels in older adults.

BACKGROUND: This study examined the construct validity and reliability of the new 2-item Stanford Brief Activity Survey (SBAS). METHODS: Secondary analysis was conducted using data collected from the healthy older controls (n = 1023) enrolled in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study. Construct validity was examined by regression analyses to evaluate significant trends (P < or = .05) across the SBAS activity categories for the selected psychological health factors measured at baseline and year 2, adjusted for gender, ethnicity and education level. Test-retest reliability was performed using Spearman's rank correlation. RESULTS: At baseline, subjects were 66 +/- 2.8 years old, 38% female, 77% married, 61% retired, 24% college graduate, and 68% Caucasian. At baseline, lower self-reported stress, anxiety, depression, and cynical distrust, and higher self-reported mental and physical well-being were significantly associated with higher levels of physical activity (p trend < or = 0.01). These associations held at year 2. The test-retest reliability of the SBAS was statistically significant (r(s)= 0.62, P < .001). CONCLUSION: These results provide evidence of the construct validity and reliability of the SBAS in older adults. We also found a strong dose-response relationship between regular physical activity and psychological health in older adults, independent of gender, education level and ethnicity.

A randomized controlled trial of culturally tailored dance and reducing screen time to prevent weight gain in low-income African American girls: Stanford GEMS.

OBJECTIVE: To test a 2-year community- and family-based obesity prevention program for low-income African American girls: Stanford GEMS (Girls' health Enrichment Multi-site Studies). DESIGN: Randomized controlled trial with follow-up measures scheduled at 6, 12, 18, and 24 months. SETTING: Low-income areas of Oakland, California. PARTICIPANTS: African American girls aged 8 to 10 years (N=261) and their parents or guardians. INTERVENTIONS: Families were randomized to one of two 2-year, culturally tailored interventions: (1) after-school hip-hop, African, and step dance classes and a home/family-based intervention to reduce screen media use or (2) information-based health education. MAIN OUTCOME MEASURE: Changes in body mass index (BMI). RESULTS: Changes in BMI did not differ between groups (adjusted mean difference [95% confidence interval] = 0.04 [-0.18 to 0.27] per year). Among secondary outcomes, fasting total cholesterol level (adjusted mean difference, -3.49 [95% confidence interval, -5.28 to -1.70] mg/dL per year), low-density lipoprotein cholesterol level (-3.02 [-4.74 to -1.31] mg/dL per year), incidence of hyperinsulinemia (relative risk, 0.35 [0.13 to 0.93]), and depressive symptoms (-0.21 [-0.42 to -0.001] per year) decreased more among girls in the dance and screen time reduction intervention. In exploratory moderator analysis, the dance and screen time reduction intervention slowed BMI gain more than health education among girls who watched more television at baseline (P = .02) and/or those whose parents or guardians were unmarried (P = .01). CONCLUSIONS: A culturally tailored after-school dance and screen time reduction intervention for low-income, preadolescent African American girls did not significantly reduce BMI gain compared with health education but did produce potentially clinically important reductions in lipid levels, hyperinsulinemia, and depressive symptoms. There was also evidence for greater effectiveness in high-risk subgroups of girls.

Estimating physical activity from incomplete accelerometer data in field studies.

BACKGROUND: The purpose of this study was to develop a data-driven approach for analyzing incomplete accelerometer data from field-base studies. METHODS: Multiple days of accelerometer data from the Stanford Girls health Enrichment Multi-site Studies (N = 294 African American girls) were summed across each minute of each day to produce a composite weekday and weekend day. Composite method estimates of physical activity were compared with those derived from methods typically described in the literature (comparison methods). RESULTS: The composite method retained 99.7% and 100% of participants in weekday and weekend-day analysis, respectively, versus 84.7% to 94.2% and 28.6% to 99.0% for the comparison methods. Average wearing times for the composite method for weekday and weekend day were 99.6% and 98.6%, respectively, 91.7% to 93.9% and 82.3% to 95.4% for the comparison methods. Composite-method physical activity estimates were similar to comparison-methods estimates. CONCLUSION: The composite method used more available accelerometer data than standard approaches, reducing the need to exclude periods within a day, entire days, and participants from analysis.