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1.
Public Health ; 182: 193-198, 2020 May.
Article in English | MEDLINE | ID: mdl-32375100

ABSTRACT

OBJECTIVE: Few parent-targeted interventions have examined the mechanisms of action by which the intervention changes child behavior. The purpose of this study was to test the theoretical and behavioral mediators of the Smart Moms intervention on changes in child sugar-sweetened beverage and juice (SSB/juice) consumption. STUDY DESIGN: This is a secondary mediation analysis of data from a 6-month randomized controlled trial (N = 51 mother-child dyads) of a mobile phone-based program to reduce child SSB/juice intake compared with a waitlist control group. METHODS: Linear mixed models compared changes in intervention targets from baseline to 3 months between treatment groups. Intervention targets that changed significantly between groups were tested in a multiple mediation model to evaluate their significance as mediators of change in child SSB/juice at 6 months. RESULTS: Maternal beverage consumption but no other behavioral or theoretical intervention targets mediated the effect of the intervention on the reduction in child SSB/juice at 6 months. There were few mediators of the intervention on child SSB/juice change. CONCLUSION: Greater longitudinal research is needed to understand predictors of child dietary changes to inform future intervention efforts. In addition, a greater focus on the measurement of theoretical constructs in family-based child obesity prevention research is needed.


Subject(s)
Feeding Behavior , Health Promotion/methods , Mothers , Pediatric Obesity/prevention & control , Sugar-Sweetened Beverages , Adult , Behavior Therapy/methods , Cell Phone , Child, Preschool , Diet , Female , Fruit and Vegetable Juices , Humans , Male , Parents , Sweetening Agents/administration & dosage
2.
Child Care Health Dev ; 44(5): 746-752, 2018 09.
Article in English | MEDLINE | ID: mdl-29873093

ABSTRACT

BACKGROUND: Family childcare homes (FCCHs) are the second largest provider of childcare in the United States, yet little is known about how this setting influences children's physical activity, particularly related to the physical environment. Thus, the purpose of this study was to determine what aspects of the FCCH physical environment facilitate or hinder children's physical activity. METHODS: Data were collected from 166 FCCH providers and 496 preschool-aged children in 2013-2014 as part of the Keys to Healthy FCCHs study. Children's moderate-to-vigorous physical activity (MVPA) was measured using Actigraph GT3X+ accelerometers. Wear data from the childcare day were isolated, and cut-points were applied in order to calculate children's minutes of MVPA per hour. FCCH-level estimates of child MVPA per hour were calculated. Indoor and outdoor physical environment characteristics were assessed during a 2-day observation using the Environment and Policy Assessment and Observation modified for FCCHs. General linear models were used to examine the relationship between indoor, portable play equipment, and outdoor FCCH physical environment characteristics and children's MVPA per hour. RESULTS: Only indoor play space was significantly associated with children's MVPA (ß = 0.33; p = .034), indicating that when provided with more indoor space for active play, children were more physically active. No significant associations were noted between portable play equipment or the outdoor environment and children's MVPA. CONCLUSIONS: Indoor space was the only physical environment characteristic associated with children's MVPA, suggesting that teaching FCCH providers how to best utilize their indoor play space for active play may be a way to promote children's physical activity. Futures studies should explore the impact of other environmental characteristics of the FCCH (e.g., provider practices and policies) on children's physical activity.


Subject(s)
Child Care/methods , Child Day Care Centers , Exercise/physiology , Health Promotion , Play and Playthings , Accelerometry , Child, Preschool , Cluster Analysis , Female , Humans , Male
3.
Pediatr Obes ; 13(11): 668-676, 2018 11.
Article in English | MEDLINE | ID: mdl-29119719

ABSTRACT

BACKGROUND: Sugar-sweetened beverages and maternal weight are strong drivers of child obesity, but few studies have targeted these risk factors as an obesity prevention strategy in children. OBJECTIVE: The objective of this study was to test the efficacy of a smartphone-delivered intervention to reduce parent-provided sugar-sweetened beverage and juice (SSB/juice) consumption among children ages 3-5 and maternal weight. METHODS: Mothers with overweight or obesity, who had a child ages 3-5 that consumed at least 12 fl. oz./day of SSB/juice (N = 51 dyads) were randomized to the Smart Moms group that received one group session, lessons on a mobile website, and text messages, or to a waitlist control group. Mothers self-monitored their children's beverages in addition to their own beverages, high-calorie foods, and weight. Assessments at baseline, 3, and 6 months included dietary recalls to measure SSB/juice intake and objectively measured maternal weight. RESULTS: Using linear mixed models controlling for baseline values, child age and race, there was a greater reduction in child SSB/juice in Smart Moms compared with control at 6 months (-9.7 oz./day vs. 1.7 oz./day, p < .01). Mothers in Smart Moms lost 2.4 kg at 6 months compared with a 0.9-kg gain in the control group (p < .01). CONCLUSIONS: An intervention delivered using mHealth technologies can target mothers to change child dietary behaviours and improve maternal weight, which suggests a novel approach to family-based obesity prevention.


Subject(s)
Beverages , Obesity , Sweetening Agents , Telemedicine , Weight Reduction Programs , Child, Preschool , Female , Humans , Male , Beverages/adverse effects , Beverages/statistics & numerical data , Body Weight , Diet/statistics & numerical data , Feeding Behavior , Health Behavior , Health Education/methods , Mothers , Obesity/prevention & control , Smartphone , Sweetening Agents/administration & dosage , Sweetening Agents/adverse effects , Telemedicine/methods , Waiting Lists , Weight Reduction Programs/methods , Adult
4.
Obes Rev ; 18(12): 1425-1438, 2017 12.
Article in English | MEDLINE | ID: mdl-28960764

ABSTRACT

INTRODUCTION: Social marketing is a promising planning approach for influencing voluntary lifestyle behaviours, but its application to nutrition and physical activity interventions in the early care and education setting remains unknown. METHODS: PubMed, ISI Web of Science, PsycInfo and the Cumulative Index of Nursing and Allied Health were systematically searched to identify interventions targeting nutrition and/or physical activity behaviours of children enrolled in early care centres between 1994 and 2016. Content analysis methods were used to capture information reflecting eight social marketing benchmark criteria. RESULTS: The review included 135 articles representing 77 interventions. Two interventions incorporated all eight benchmark criteria, but the majority included fewer than four. Each intervention included behaviour and methods mix criteria, and more than half identified audience segments. Only one-third of interventions incorporated customer orientation, theory, exchange and insight. Only six interventions addressed competing behaviours. We did not find statistical significance for the effectiveness of interventions on child-level diet, physical activity or anthropometric outcomes based on the number of benchmark criteria used. CONCLUSION: This review highlights opportunities to apply social marketing to obesity prevention interventions in early care centres. Social marketing could be an important strategy for early childhood obesity prevention efforts, and future research investigations into its effects are warranted.


Subject(s)
Child Day Care Centers/standards , Diet , Exercise , Nutrition Policy , Social Marketing , Benchmarking , Child Care/standards , Child, Preschool , Humans
5.
Anaesthesia ; 72(7): 923-924, 2017 07.
Article in English | MEDLINE | ID: mdl-28608381
6.
Child Care Health Dev ; 42(3): 351-8, 2016 May.
Article in English | MEDLINE | ID: mdl-26987658

ABSTRACT

BACKGROUND: Obesity prevention in young children is a public health priority. In the USA, nearly 10% of children less than 5 years of age are obese, and most attend some form of out-of-home child care. While a number of interventions have been conducted in early care and education settings, few have targeted the youngest children in care or the less formal types of child care like family child care homes. Additionally, only two previous studies provided recommendations to help inform future interventions. METHODS: This paper presents lessons learned from two distinct intervention studies in early care and education settings to help guide researchers and public health professionals interested in implementing and evaluating similar interventions. We highlight two studies: one targeting children ages 4 to 24 months in child care centres and the other intervening in children 18 months to 4 years in family child care homes. We include lessons from our pilot studies and the ongoing larger trials. RESULTS: To date, our experiences suggest that an intervention should have a firm basis in behaviour change theory; an advisory group should help evaluate intervention materials and plan for delivery; and realistic recruitment goals should recognize economic challenges of the business of child care. A flexible data collection approach and realistic sample size calculations are needed because of high rates of child (and sometimes facility) turnover. An intervention that is relatively easy to implement is more likely to appeal to a wide variety of early care and education providers. CONCLUSIONS: Interventions to prevent obesity in early care and education have the potential to reach large numbers of children. It is important to consider the unique features and similarities of centres and family child care homes and take advantage of lessons learned from current studies in order to develop effective, evidence-based interventions.


Subject(s)
Pediatric Obesity/prevention & control , Preventive Health Services/organization & administration , School Health Services , Adiposity , Child Day Care Centers , Child, Preschool , Clinical Trials as Topic , Diet , Exercise , Female , Humans , Infant , Male , Pilot Projects , Program Development , School Health Services/organization & administration , United States
7.
Int J Obes (Lond) ; 37(10): 1322-7, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23736369

ABSTRACT

BACKGROUND: Providing personalized genetic-risk feedback of a child's susceptibility to adult-onset health conditions is a topic of considerable debate. Family health history (FHH), specifically parental overweight/obesity status, is a useful assessment for evaluating a child's genetic and environmental risk of becoming obese. It is unclear whether such risk information may influence parents' efforts to reduce their child's risk of obesity. PURPOSE: To evaluate whether telling mothers the magnitude of their child's risk of becoming obese based on personal FHH influenced food choices for their young child from a virtual reality-based buffet restaurant. METHODS: Overweight/obese mothers of a child aged 4-5 years who met eligibility criteria (N=221) were randomly assigned to one of three experimental arms, which emphasized different health information: arm 1, food safety control (Control); arm 2, behavioral-risk information (BRI) alone or arm 3, behavioral-risk information plus personal FHH-based risk assessment (BRI+FHH). Mothers donned a head-mounted display to be immersed in a virtual restaurant buffet, where they selected virtual food and beverages as a lunch for their child. RESULTS: Mothers who were randomized to BRI+FHH filled the index child's plate with an average of 45 fewer calories than those in the Control arm (P<0.05); those in the BRI arm filled the plate with 35 fewer calories than the Control arm, a non-significant difference. Calorie restriction was greatest among mothers in the BRI+FHH arm who received the weaker-risk message (that is, only one overweight parent). CONCLUSIONS: The influence of communicating a child's inherited risk of obesity on mothers' feeding practices may vary by the risk level conveyed. High-risk messages may best be coupled with strategies to increase mother's perceptions that efforts can be undertaken to reduce risk and build requisite behavioral skills to reduce risk.


Subject(s)
Choice Behavior , Feeding Behavior , Maternal Behavior , Mothers , Parenting , Pediatric Obesity/prevention & control , User-Computer Interface , Adult , Body Mass Index , Child Nutritional Physiological Phenomena , Child, Preschool , Feedback , Feeding Behavior/psychology , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Maternal Behavior/psychology , Mothers/psychology , Pediatric Obesity/epidemiology , Pediatric Obesity/psychology , Social Environment , Socioeconomic Factors , Surveys and Questionnaires , United States/epidemiology
8.
Anaesthesia ; 67(2): 186-7, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22251113
9.
Health Educ Res ; 27(2): 319-30, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22156233

ABSTRACT

Sustained intervention effects are needed for positive health impacts in populations; however, few published examples illustrate methods for assessing sustainability in health promotion programs. This paper describes the methods for assessing sustainability of the Lifestyle Education for Activity Program (LEAP). LEAP was a comprehensive school-based intervention that targeted change in instructional practices and the school environment to promote physical activity (PA) in high school girls. Previous reports indicated that significantly more girls in the intervention compared with control schools reported engaging in vigorous PA, and positive long-term effects on vigorous PA also were observed for girls in schools that most fully implemented and maintained the intervention 3 years following the active intervention. In this paper, the seven steps used to assess sustainability in LEAP are presented; these steps provide a model for assessing sustainability in health promotion programs in other settings. Unique features of the LEAP sustainability model include assessing sustainability of changes in instructional practices and the environment, basing assessment on an essential element framework that defined complete and acceptable delivery at the beginning of the project, using multiple data sources to assess sustainability, and assessing implementation longitudinally.


Subject(s)
Health Education , Health Promotion , Life Style , Motor Activity , Program Evaluation/methods , Adolescent , Female , Health Education/organization & administration , Humans , Interviews as Topic , Male
10.
Anaesthesia ; 66 Suppl 2: 19-26, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22074075

ABSTRACT

Airway management is primarily designed to avoid hypoxia, yet hypoxia remains the main ultimate cause of anaesthetic-related death and morbidity. Understanding some of the physiology of hypoxia is therefore essential as part of a 'holistic' approach to airway management. Furthermore, it is strategically important that national specialist societies dedicated to airway management do not only focus upon the technical aspects of airway management, but also embrace some of the relevant scientific questions. There has been a great deal of research into causation of hypoxia and the body's natural protective mechanisms and responses to it. This enables us to think of ways in which we might manipulate the cellular and molecular responses to confer greater protection against hypoxia-induced tissue injury. This article reviews some of those aspects.


Subject(s)
Airway Management/methods , Hypoxia/therapy , Adaptation, Physiological/physiology , Analgesics, Opioid/adverse effects , Anesthesia Recovery Period , Anesthesia, Inhalation , Anesthetics, Inhalation/pharmacology , Humans , Hypoxia/etiology , Hypoxia/physiopathology , Mitochondria/metabolism , Mitochondria/physiology , Pulmonary Atelectasis/chemically induced , Pulmonary Atelectasis/physiopathology , Respiration, Artificial , Respiratory Mechanics/physiology
11.
Adv Exp Med Biol ; 605: 475-9, 2008.
Article in English | MEDLINE | ID: mdl-18085320

ABSTRACT

The effects of audiovisual stimulation on the temporal patterns of V(T), T(I), T(E) were studied in 11 healthy subjects. 75 datasets of steady-state breathing each of eight minutes in duration were obtained during low wakefulness (lying still, eyes closed), low wakefulness with calibrated thermal pain stimulation and high wakefulness (playing a computer game). The analysis included removal of trend and mean, interpolation and re-sampling of the data to provide an equi-spaced time basis, test for normal distribution of datasets, power spectral estimation, estimation of the parameters of 1st and 2nd order autocorrelation models and estimation of the same parameters on the residuals following subtraction of the 1st or 2nd order models. All power spectra showed the highest power at the lowest frequencies; correspondingly the 1st order autocorrelation coefficients were significant at the 5% level except for T(E) (p = 0.12). The 2nd order coefficients were non-significant for all series. The 1st order autocorrelation coefficients of the residuals (after subtraction of the 1st order autocorrelation component) were all non-significant. With 1st order autocorrelation coefficients averaging between .12 and .37 the non-random part of the variation explained by the 1st order autocorrelation structure is between 1.4% and 13.7% and independent of stimulation of breathing by thermal or mental stimuli.


Subject(s)
Acoustic Stimulation , Photic Stimulation , Respiratory Mechanics/physiology , Wakefulness/physiology , Computers , Humans , Inhalation , Oxygen/physiology , Pain/physiopathology , Play and Playthings , Reference Values
12.
Health Educ Res ; 21(6): 896-910, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17099074

ABSTRACT

Physical activity levels begin to decline in childhood and continue falling throughout adolescence, with girls being at greatest risk for inactivity. Schools are ideal settings for helping girls develop and maintain a physically active lifestyle. This paper describes the design and implementation of 'Lifestyle Education for Activity Program', or LEAP. LEAP used a health team approach with participatory strategies to provide training and support, instructional capacity building and opportunities to adapt school instructional program and environmental supports to local needs. The social-ecological model, based on social cognitive theory, served as the organizing framework for the LEAP intervention and elements of the coordinated school health program model as intervention channels. For the 12 intervention schools, LEAP staff documented 191 visits and interactions with 850 individuals over the 2-year period. Teachers reported successful implementation of most components of the intervention and demonstrated optimism for sustainability. These results indicate that a facilitative approach to intervention implementation can be used successfully to engage school personnel, and to change instructional programs and school environments to increase the physical activity level of high school girls.


Subject(s)
Environment , Health Education/organization & administration , Motor Activity , Schools/organization & administration , Adolescent , Adolescent Behavior , Female , Humans , Program Evaluation , School Health Services/organization & administration
13.
Prev Med ; 34(1): 100-8, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11749102

ABSTRACT

BACKGROUND: We previously developed questionnaires based on contemporary theories to measure physical activity determinants among youth [Motl et al., Prev Med 2000; 31:584-94]. The present study examined the factorial invariance and latent mean structure of unidimensional models fit to the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity among black and white adolescent girls. METHODS: Black (n = 896) and white (n = 823) girls in the 8th grade completed the questionnaires measuring attitude, subjective norm, perceived behavioral control, and self-efficacy about physical activity. The responses were subjected to analyses of factorial invariance and latent mean structure using confirmatory factor analysis with full-information maximum likelihood estimation in AMOS 4.0. RESULTS: The unidimensional models of the four questionnaires generally demonstrated invariance of the factor structure, factor loadings, and factor variance across race but not invariance of the variance-covariance matrices or item uniquenesses. The analyses of latent mean structure demonstrated that white girls had higher latent mean scores on the measures of attitude and self-efficacy than black girls; there were similar, but smaller, differences between white and black girls on the measures of subjective norm and perceived behavioral control. CONCLUSIONS: The questionnaires can be employed in interventions to test the mediating influences of attitude, subjective norm, perceived behavioral control, and self-efficacy on participation in physical activity by black and white adolescent girls.


Subject(s)
Adolescent Behavior/ethnology , Attitude to Health/ethnology , Black or African American/psychology , Cognition , Exercise/psychology , Health Behavior/ethnology , Interpersonal Relations , Surveys and Questionnaires , White People/psychology , Adolescent , Factor Analysis, Statistical , Female , Humans , Self Efficacy , South Carolina
14.
Int J Obes Relat Metab Disord ; 25(6): 822-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11439296

ABSTRACT

OBJECTIVE: To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN: Cross-sectional study. SUBJECTS: One-hundred and thirty-three non-obese and 54 obese sixth grade children (mean age of 11.4+/-0.6). Obesity status determined using the age-, race- and gender-specific 95th percentile for BMI from NHANES-1. MEASUREMENTS: Objective measurements were collected of PA over a 7-day period using the CSA 7164 accelerometer: total daily counts; daily moderate (3-5.9 METs) physical activity (MPA); daily vigorous physical activity (> or =6 METs; VPA); and weekly number of 5, 10 and 20 min bouts of moderate-to-vigorous physical activity (> or =3 METs, MVPA). Self-report measures were collected of PA self-efficacy; social influences regarding PA, beliefs about PA outcomes; perceived PA levels of parents and peers, access to sporting and/or fitness equipment at home, involvement in community-based PA organizations; participation in community sports teams; and hours spent watching television or playing video games. RESULTS: Compared to their non-obese counterparts, obese children exhibited significantly lower daily accumulations of total counts, MPA and VPA as well as significantly fewer 5, 10 and 20 min bouts of MVPA. Obese children reported significantly lower levels of PA self-efficacy, were involved in significantly fewer community organizations promoting PA and were significantly less likely to report their father or male guardian as physically active. CONCLUSIONS: The results are consistent with the hypothesis that physical inactivity is an important contributing factor in the maintenance of childhood obesity. Interventions to promote PA in obese children should endeavor to boost self-efficacy perceptions regarding exercise, increase awareness of, and access to, community PA outlets, and increase parental modeling of PA.


Subject(s)
Exercise , Health Behavior , Obesity/etiology , Australia , Body Mass Index , Child , Cross-Sectional Studies , Exercise/psychology , Female , Humans , Male , Nutrition Surveys , Parents/psychology , Physical Fitness , Self Efficacy , Social Environment , Time Factors
15.
Int Anesthesiol Clin ; 38(4): 127-40, 2000.
Article in English | MEDLINE | ID: mdl-11100421

ABSTRACT

Keeping the OR scheduled to satisfy all the various constituents is a complex dynamic process. The health care environment needs to be carefully analyzed to ensure that the services the OR offers are appropriate. OR utilization is not simply ensuring that the greatest number of cases are done. The cost of doing these cases must be considered and, in order to do so, compromises must be made. Creating information systems that track all aspects of utilization, including costs and revenues, will be vital for the future management of operating rooms.


Subject(s)
Operating Rooms/statistics & numerical data , Appointments and Schedules , Costs and Cost Analysis , Delivery of Health Care , Humans , Information Systems , Time Factors
16.
Prev Med ; 31(5): 584-94, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11071840

ABSTRACT

BACKGROUND: There are few theoretically derived questionnaires of physical activity determinants among youth, and the existing questionnaires have not been subjected to tests of factorial validity and invariance. The present study employed confirmatory factor analysis (CFA) to test the factorial validity and invariance of questionnaires designed to be unidimensional measures of attitudes, subjective norms, perceived behavioral control, and self-efficacy about physical activity. METHODS: Adolescent girls in eighth grade from two cohorts (N = 955 and 1,797) completed the questionnaires at baseline; participants from cohort 1 (N = 845) also completed the questionnaires in ninth grade (i.e., 1-year follow-up). Factorial validity and invariance were tested using CFA with full-information maximum likelihood estimation in AMOS 4.0. Initially, baseline data from cohort 1 were employed to test the fit and, when necessary, to modify the unidimensional models. The models were cross-validated using a multigroup analysis of factorial invariance on baseline data from cohorts 1 and 2. The models then were subjected to a longitudinal analysis of factorial invariance using baseline and follow-up data from cohort 1. RESULTS: The CFAs supported the fit of unidimensional models to the four questionnaires, and the models were cross-validated, as indicated by evidence of multigroup factorial invariance. The models also possessed evidence of longitudinal factorial invariance. CONCLUSIONS: Evidence was provided for the factorial validity and the invariance of the questionnaires designed to be unidimensional measures of attitudes, subjective norms, perceived behavioral control, and self-efficacy about physical activity among adolescent girls.


Subject(s)
Attitude , Exercise , Surveys and Questionnaires , Adolescent , Behavior , Factor Analysis, Statistical , Female , Humans , Models, Theoretical , Self Efficacy
17.
Arch Phys Med Rehabil ; 81(4): 484-9, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10768540

ABSTRACT

OBJECTIVE: To examine differences in gait and postural stability of obese and nonobese prepubertal boys. DESIGN: Percentage of gait cycle in double support was examined to determine significant differences. Postural stability was compared using temporal and frequency measures of the center of pressure in static stance. SETTING: Gait was examined using videography on a 30-meter walkway. Postural stability was examined using a measurement platform. PARTICIPANTS: Ten obese (>95th percentile in body mass index) and 10 nonobese (15th to 90th percentile in body mass index) prepubertal boys aged 8 to 10yrs. INTERVENTION: Participants were examined at three walking cadences as determined by preferred gait cadence. Full vision, darkness, and visually confused conditions were used to accentuate static postural stability differences. MAIN OUTCOME MEASURES: In the presence of dynamic stability differences (gait), static stability measures further investigated stability differences. RESULTS: Obese boys spent significantly (p < .02) greater percentage of gait cycle in dual stance. Obese boys showed significantly (p < .01) greater sway areas, energy, and variability primarily in the medial/lateral direction. CONCLUSIONS: Dual stance differences suggest diminished dynamic stability in obese boys. Greater sway areas in medial/lateral direction in obese boys and the absence of significant frequency measures suggest that the instability observed in obese boys is caused by excess weight rather than underlying postural instability.


Subject(s)
Gait , Obesity/physiopathology , Postural Balance , Child , Humans , Male
18.
J Clin Monit Comput ; 16(3): 191-9, 2000.
Article in English | MEDLINE | ID: mdl-12578103

ABSTRACT

OBJECTIVE: Near-infrared spectroscopy (NIRS) has the potential for providing valuable information about oxygen delivery to the brain. However, questions have been raised about the accuracy of these measurements. This study was undertaken to compare noninvasive cerebral saturation measurements to jugular venous saturation under conditions of hypoxia and hypercapnia. METHODS: Data was obtain on forty-two subjects. Cerebral oxygenation was measured with a Somanetics INVOS 4100-SSA placed on the forehead of the subjects. PETCO2 was controlled to approximately 2 and 7 mmHg above resting values and PETO2 was controlled to 80, 45, 60 and 41 mmHg consecutively for four of five minutes each. Internal jugular blood gas measurements were made via a retrograde catheter. RESULTS: Both the cerebral oximetry measured saturation (rSO2) and the jugular venous saturation (SjvO2) were significantly increased by increasing the PETCO2 at all levels of hypoxia. The increase in the rSO2 was less than the increase in SjvO2. The rSO2 had a bias of 5.2% and a precision of 10.7% compared to the measured SjvO2. DISCUSSION: Cerebral oxygen saturation measured by cerebral oximetry compares well to the measured SjvO2 in normal subjects, despite multiple physiological reasons for differences. The closer relationship of SjvO2 to rSO2 than SaO2 under the conditions of these experiments indicates that the measurement reflects primarily intracranial saturation. However, outcome studies under clinical conditions are needed to determine the clinical utility of cerebral oximetry.


Subject(s)
Cerebral Arteries , Hypoxia/blood , Jugular Veins , Oximetry , Adult , Blood Gas Monitoring, Transcutaneous , Cerebrovascular Circulation , Female , Humans , Hypercapnia/blood , Male , Spectroscopy, Near-Infrared
19.
Aviat Space Environ Med ; 70(11): 1070-6, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10608603

ABSTRACT

PURPOSE: The effect of endurance training on vascular volumes in females has received little research attention. Further, the effect of exercise training intensity on vascular volumes is unknown. Therefore, we investigated the hypothesis that greater hematologic changes would be induced in women by higher exercise intensity during endurance training. METHODS: There were 26 healthy, sedentary adult females with the following characteristics (mean +/- SD): maximal oxygen consumption (VO2max) = 30.0+/-6.6 ml x kg(-1) x min(-1); age = 32+/-5 yr; body mass index (BMI) = 23.7+/-3.6 kg x m(-2)) who were randomly assigned to control (CON, n = 8); high intensity (HI, 80% of VO2max, n = 10), or low intensity (LO, 40% of VO2max, n = 8) cycle ergometer training groups. Training, conducted 3-5 (3.37+/-0.05) d x wk(-1) for 12 wk, was supervised. Estimated exercise energy expenditure was equated across training groups, progressing from 150-375 kcal per session (mean +/- SE across training weeks = 298+/-0.34 and 297+/-0.37 kcal per session for HI and LO, respectively). Plasma volume (PV, T-1824 dilution); calculated total blood (TBV) and red cell volumes (RCV); calculated total hemoglobin (THb); erythropoietin concentration ([Epo]) and selected hematologic variables were measured at baseline and weeks 2, 4, 8 and 12 of training. RESULTS: The observed relative (percent) changes in PV, TBV, RCV and THb from pre-training baseline values were not statistically significant. Decreases (p < 0.05) in hematocrit (Hct), hemoglobin ([Hb]) and RBC count were observed in both training groups. Mean corpuscular Hb (MCH) and Hb concentration (MCHC) increased (p < 0.05) during training. [Epo] was decreased at week 2 compared with baseline (p < 0.03), but was similar to baseline at weeks 4, 8 and 12. CONCLUSIONS: Within the limits of this study, endurance training did not increase PV, TBV, RCV and THb in previously sedentary females regardless of the intensity of training.


Subject(s)
Blood Volume/physiology , Exercise Therapy/methods , Physical Endurance/physiology , Women , Adaptation, Physiological/physiology , Adult , Body Mass Index , Erythrocyte Indices , Erythropoietin/blood , Exercise Test , Female , Hematocrit , Hemoglobins/analysis , Humans , Oxygen Consumption/physiology , Time Factors
20.
Am J Prev Med ; 17(2): 120-6, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10490054

ABSTRACT

OBJECTIVE: The purpose of this study was to identify the psychosocial and environmental correlates of objectively measured physical activity behavior in a diverse sample of sixth-grade students. DESIGN: Cross-sectional. PARTICIPANTS AND SETTINGS: One hundred ninety-eight sixth-grade students from 4 public middle schools in Columbia, South Carolina. The study group was 52.0% female, 55.1% African-American, with a mean age of 11.4 +/- 0.6 years. MAIN OUTCOME MEASURES: Time spent in moderate physical activity (MPA) and vigorous physical activity (VPA) was assessed using a uniaxial accelerometer (CSA WAM 7164) (Computer Science and Applications Inc., Shalimar, FL). Determinant variables included: age, gender, race/ethnicity (demographic); physical activity self-efficacy, social norms related to physical activity, and beliefs regarding physical activity outcomes (psychosocial); and perceived physical activity habits of parents and peers, involvement in community physical activity organizations, involvement in community-based sports programs, access to fitness/sporting equipment at home, and self-reported hours spent watching television or playing video games (environmental). RESULTS: For boys, physical activity self-efficacy, social norms related to physical activity, and involvement in community physical activity organizations were salient predictors of MPA and VPA. Among girls, only physical activity self-efficacy emerged as a clear predictor of objectively measured physical activity. CONCLUSIONS: These findings are consistent with previous studies using self-reported physical activity and suggest that interventions to increase physical activity in preadolescent youth should endeavor to boost physical activity self-efficacy by offering a wide selection of enjoyable, developmentally-appropriate physical activity options.


Subject(s)
Exercise , Health Behavior , Health Knowledge, Attitudes, Practice , Child , Cross-Sectional Studies , Female , Humans , Male , Multivariate Analysis , Physical Fitness/physiology , Regression Analysis , Sampling Studies , Sex Factors , Socioeconomic Factors , South Carolina , Surveys and Questionnaires
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