Components of the transtheoretical model of change were examined in a prospective study of the adoption of vigorous exercise in adults. Respondents to a random mail survey were resurveyed 2 years later. Those who reported no vigorous exercise at baseline were classified as either contemplators ( n = 213) or precontemplators ( n = 188). Contemplators had higher baseline self-efficacy scores than precontemplators (p < .001). In multivariate analyses, baseline stage of change was a significant predictor (p < .0005) of later adoption of vigorous exercise, even after controlling for differences in age, gender, and self-efficacy. During the first 6 months postbaseline, contemplators were nearly twice as likely as precontemplators to progress to the stage of action (46% vs. 24%), and four times more likely to progress to the stage of maintenance (25% vs. 6%). Use of the transtheoretical model in the study of exercise was supported in this prospective examination of exercise in a community sample.
Self-monitoring is often used in health behaviour change programs; but it is not known to what extent self-monitoring data are valid and useful in predicting changes in cardiovascular disease (CVD) risk. Subjects included 72 Anglo adults, 68 Anglo children, 80 Mexican-American adults and 94 Mexican-American children. Subjects were families with fifth and sixth grade children who participated in an 18-session family-based diet and exercise change program designed to reduce CVD risk. During the intervention, each participant self-monitored diet and aerobic physical activity. Families were measured at baseline, 3, 12, and 24 months. For adults, self-monitored changes in diet correlated with changes in body mass index, systolic blood pressure, total cholesterol and LDL 1 and 2 years later. Correlations between self-monitored diet and diet-related risk factor changes were not observed among children. Correlations between self-monitored exercise and subsequent risk factor changes were not observed among adults. For children, self monitored changes in aerobic physical activity correlated significantly with changes in VO2Max and HDL/LDL ratio 1 and 2 years later. Thus, this study provides some support for the predictive validity of diet self-monitoring in adults and exercise self-monitoring in children.
Many human cancers carry missense mutations in or deletions of the tumor protein 53 (TP53) tumor suppressor gene. TP53's product, p53 regulates many biological processes, including cell metabolism. Cholesterol is a key lipid needed for the maintenance of membrane function and tissue homeostasis while also serving as a precursor for steroid hormone and bile acid synthesis. An over-abundance of cholesterol can lead to its esterification and storage as cholesterol esters. The recent study has shown that the loss of p53 leads to excessive cholesterol ester biosynthesis, which promotes hepatocellular carcinoma in mice. Blocking cholesterol esterification improves treatment outcomes, particularly for liver cancers with p53 deletions/mutations that originate in a background of non-alcoholic fatty liver disease.
No abstract is provided for this article.
Background Our objective was to evaluate the effects of environmental, policy, and social marketing interventions on physical activity and fat intake of middle school students on campus. Design Twenty-four middle schools were randomly assigned to intervention or control conditions. Baseline measures were collected in spring 1997, and interventions were conducted during the 1997–1998 and 1998–1999 school years. Setting/participants The schools had mean enrollments of 1109, with 44.5% nonwhite students. Intervention Over 2 years, physical activity interventions were designed to increase physical activity in physical education classes and throughout the school day. Nutrition interventions were designed to provide and market low-fat foods at all school food sources, including cafeteria breakfasts and lunches, a la carte sources, school stores, and bag lunches. School staff and students were engaged in policy change efforts, but there was no classroom health education. Main outcome measures Primary outcomes were measured by direct observation and existing records. Results Randomized regression models (N =24 schools) revealed a significant intervention effect for physical activity for the total group (p <0.009) and boys (p <0.001), but not girls (p <0.40). The intervention was not effective for total fat (p <0.91) or saturated fat (p <0.79). Survey data indicated that the interventions reduced reported body mass index for boys (p <0.05). Conclusions Environmental and policy interventions were effective in increasing physical activity at school among boys but not girls. The interventions were not effective in reducing fat intake at school. School environmental and policy interventions have the potential to improve health behavior of the student population, but barriers to full implementation need to be better understood and overcome.
The decline in physical activity with age may be the most consistent finding in physical activity epidemiology. Although this phenomenon is well accepted, it is not well understood. A related issue is that females are typically found to have lower levels of physical activity at virtually all ages, and the age-related decline is greater in females. The purposes of this symposium are to quantify the decline in physical activity within different age ranges, determine if there are critical periods of decline, and quantify sex differences in the decline. To evaluate the generalizability of age and sex differences, data from cross-sectional and prospective studies of subjects from different age groups will be presented. The studies use a variety of self-report and objective methods of assessing physical activity, and they have been conducted in several nations. The potential biological bases of age and sex differences in physical activity will be explored in a presentation on results from studies of several species of non-human animals. It is hoped this symposium will stimulate further research on this fundamental feature of physical activity. The decline in physical activity with age is antithetical to public health goals, so methods of countering the decline need to be developed, based upon an improved understanding.
Objective We examined the prevalence and correlates of dog walking among dog owners, and whether dog walking is associated with meeting the American College of Sports Medicine/American Heart Association physical activity guidelines. Methods In March 2008, we mailed a survey to dog-owning clients from two San Diego County veterinary clinics. Useable data were obtained from 984 respondents, and 75 of these completed retest surveys. We assessed associations between potential correlates and dog walking (i.e., yes/no dog walking for at least 10 min in past week). Results Test–retest reliability of measures was generally high. Approximately one-third of the sample (31.5%) were not dog walkers. Proportions of dog walkers versus non-dog walkers meeting United States guidelines were 64.3% and 55.0%, respectively. Dog walking was independently associated with meeting guidelines in a multivariate model (odds ratio=1.59, p =0.004). Three variables were independently associated with dog walking in a multivariate model: dog encouragement of dog walking, dog-walking obligation, and dog-walking self-efficacy. Conclusion Dog walking was associated with meeting physical activity guidelines, making it a viable method for promoting physical activity. Dog-walking obligation and self-efficacy may be important mediators of dog walking and may need to be targeted if interventions are to be successful.
