Sex and race/ethnicity specific reference predictive equations for abdominal adiposity indices using anthropometry in US adults.

BACKGROUND AND AIMS: Abdominal adiposity indices have stronger associations with cardiometabolic risk factors compared to anthropometric measures but are rarely used in large scale studies due to the cost and efficiency. The aim of this study is to establish sex and race/ethnicity specific reference equations using anthropometric measures. METHODS AND RESULTS: A secondary data analysis (n = 6589) of healthy adults was conducted using data from National Health and Nutrition Examination Survey 2011-2018. Variables included in the analyses were anthropometric measures (height; weight; waist circumference, WC) and abdominal adiposity indices (android percent fat; android to gynoid ratio, A/G ratio; visceral adipose tissue area, VATA; visceral to subcutaneous adipose area ratio, VSR). Multivariable prediction models were developed using quantile regression. Bland-Altman was used for external validation of prediction models. Reference equations to estimate android percent fat, A/G ratio, VATA and VSR from anthropometric measurements were developed using a randomly selected subsample of 4613. These reference equations for four abdominal adiposity indices were then cross-validated in the remaining subsample of 1976. The measured and predicted android percent fat, A/G ratio, VATA and VSR were not statistically different (p > 0.05) except for the A/G ratio in Asian males and VSR in White females. The results of Bland-Altman further revealed that ≥93% of predicted abdominal adiposity indices fell within the limits of agreement (±1.96 standard deviation). CONCLUSION: The sex and race/ethnicity specific reference equations for abdominal adiposity indices established using anthropometrics in the present study have strong predictive ability in US healthy adults.

The Sex and Race/Ethnicity-Specific Relationships of Abdominal Fat Distribution and Anthropometric Indices in US Adults.

The purpose of this study was to examine demographic-specific relationships between direct abdominal fat measures and anthropometric indices. A cross-sectional study was conducted utilizing abdominal fat measures (visceral fat area, VFA; visceral to subcutaneous adipose area ratio, VSR) and anthropometrics (body mass index, BMI; waist circumference, WC) data from the 2011-2018 National Health and Nutrition Examination Survey. Linear or polynomial linear regression models were used to examine the relationships of abdominal fat measures to anthropometrics with adjustment for demographics. The results revealed that while VFA was linearly related to BMI and WC across all demographics (p < 0.001), the relationships between VSR and both BMI and WC were concave in men and convex in women. The relationships between VFA, VSR, and BMI, WC varied by sex and race/ethnicity. In conclusion, increasing BMI and WC were linearly associated with increased VFA, but their relationships with VSR were nonlinear and differed by sex.

Impact of an online healthful eating and physical activity program for college students.

PURPOSE: To identify impact of an online nutrition and physical activity program for college students. DESIGN: Randomized, controlled trial using online questionnaires and on-site physical and fitness assessments with measurement intervals of 0 (baseline), 3 (postintervention), and 15 months (follow-up). SETTING: Online intervention delivered to college students; a centralized Web site was used for recruitment, data collection, data management, and intervention delivery. SUBJECTS: College students (18-24 years old, n = 1689), from eight universities (Michigan State University, South Dakota State University, Syracuse University, The Pennsylvania State University, Tuskegee University, University of Rhode Island, University of Maine, and University of Wisconsin). INTERVENTION: A 10-lesson curriculum focusing on healthful eating and physical activity, stressing nondieting principles such as size acceptance and eating competence (software developer: Rainstorm, Inc, Orono, Maine). MEASURES: Measurements included anthropometrics, cardiorespiratory fitness, fruit/vegetable (FV) intake, eating competence, physical activity, and psychosocial stress. ANALYSIS: Repeated measures analysis of variance for outcome variables. RESULTS: Most subjects were white, undergraduate females (63%), with 25% either overweight or obese. Treatment group completion rate for the curriculum was 84%. Over 15 months, the treatment group had significantly higher FV intake (+.5 cups/d) and physical activity participation (+270 metabolic equivalent minutes per week) than controls. For both groups, anthropometric values and stress increased, and fitness levels decreased. Gender differences were present for most variables. First-year males and females gained more weight than participants in other school years. CONCLUSION: A 10-week online nutrition and physical activity intervention to encourage competence in making healthful food and eating decisions had a positive, lasting effect on FV intake and maintained baseline levels of physical activity in a population that otherwise experiences significant declines in these healthful behaviors.

Physical and mental health-related correlates of physical function in community dwelling older adults: a cross sectional study.

BACKGROUND: Physical function is the ability to perform both basic and instrumental activities of daily living, and the ability of older adults to reside in the community depends to a large extent on their level of physical function. Multiple physical and health-related variables may differentially affect physical function, but they have not been well characterized. The purpose of this investigation was to identify and examine physical and mental health-related correlates of physical function in a sample of community-dwelling older adults. METHODS: Nine hundred and four community dwelling older men (n = 263) and women (n = 641) with a mean (95% Confidence Interval) age of 76.6 (76.1, 77.1) years underwent tests of physical function (Timed Up and Go; TUG), Body Mass Index (BMI) was calculated from measured height and weight, and data were collected on self-reported health quality of life (SF-36), falls during the past 6 months, number of medications per day, depression (Geriatric Depression Scale; GDS), social support, and sociodemographic variables. RESULTS: Subjects completed the TUG in 8.7 (8.2, 9.2) seconds and expended 6,976 (6,669, 7,284) Kcal.wk-1 in physical activity. The older persons had a mean BMI of 27. 6 (27.2, 28.0), 62% took 3 or more medications per day, and 14.4% had fallen one or more times over the last 6 months. Mean scores on the Mental Component Summary (MCS) was 50.6 (50.2, 51,0) and the Physical Component Summary (PCS) was 41.3 (40.8, 41.8).Multiple sequential regression analysis showed that, after adjustment for TUG floor surface correlates of physical function included age, sex, education, physical activity (weekly energy expenditure), general health, bodily pain, number of medications taken per day, depression and Body Mass Index. Further, there is a dose response relationship such that greater degree of physical function impairment is associated with poorer scores on physical health-related variables. CONCLUSIONS: Physical function in community-dwelling older adults is associated with several physical and mental health-related factors. Further study examining the nature of the relationships between these variables is needed.

Long-term effects of a stage-based intervention for changing exercise intentions and behavior in older adults.

PURPOSE: We examined the efficacy of an intervention tailored to the individual's stage of change for exercise adoption on exercise stage of change, physical activity, and physical function in community-dwelling older adults. DESIGN AND METHODS: We randomized participants to a print and telephone intervention or a contact comparison group. Through the use of longitudinal analyses we examined the intervention's effectiveness in promoting stage progression, altering decisional balance and the processes of change, increasing self-efficacy and physical activity, and improving physical function among older adults who completed the 24-month study (N = 966). We conducted similar analyses that excluded individuals who were in maintenance at baseline and 24 months. RESULTS: At the end of the study, there were no differences in stage progression, self-efficacy, decisional balance, the processes of change, physical activity, or physical function by intervention assignment. When the analyses excluded those participants (n = 358) who were in the maintenance stage for exercise throughout the intervention, we found that, compared with the comparison group, a greater proportion of individuals who received the exercise intervention progressed in stage by 24 months. Conversely, more individuals in the comparison group remained stable or regressed in stage compared with the intervention group. IMPLICATIONS: Results indicate that a tailored intervention is effective in increasing motivational readiness for exercise in individuals who were in stages of change other than maintenance.

Perceived environments as physical activity correlates and moderators of intervention in five studies.

PURPOSE: Few studies have explored how relationships of perceived environment and physical activity vary across different activity domains and populations. This question was explored in five physical activity intervention trials funded by the National Institutes of Health Behavior Change Consortium. DESIGN: Observational. SETTINGS: San Francisco peninsula, California (N = 94); Eugene, Oregon (N = 122); Atlanta, Georgia (N = 256); Kingston, Rhode Island (N = 109); Memphis, Tennessee (N = 64). SUBJECTS: Ethnically diverse community adults ages 18 to 85 years. MEASURES: The Neighborhood Environment Walkability Scale and CHAMPS physical activity questionnaire. Response rate among those invited to complete these measures was 90%. RESULTS: Cross-sectional pooled signal detection analysis indicated that people who reported living in neighborhoods with more attractive scenery and ease of walking were more likely to meet national physical activity recommendations (67%) compared with those without these neighborhood attributes (36%; chi2 = 13.04, p = .0003). Within-site multiple regression identified two additional variables--seeing others when walking and encountering loose dogs that make it difficult to walk--as correlates across multiple sites and activity domains (i.e., minutes of weekly moderate or more vigorous activity, walking for errands, walking leisurely) (incremental R2 = 2.0-7.5; p < .05). Analyses of covariance suggested that traffic safety might be particularly important in facilitating or impeding physical activity in response to a formal intervention (for traffic-arm assignment interactions, F = 3.8-7.0, p < or = .05). CONCLUSIONS: Relationships between perceived environments and physical activity may differ depending upon population groups and activity domains and merit investigation by using stronger prospective designs.