Pathways linking socioeconomic position and diabetes: The role of psychosocial factors

Despite increasing interest in the relationship between socioeconomic position (SEP) and health, there remains little understanding of the mechanisms through which SEP is related to chronic disease. This dissertation utilized data from 2,592 U.S. households in the 1995 telephone survey of the Aging, Status, and the Sense of Control study to: (1) investigate potential mediating factors in the association between educational level and prevalence of diabetes and (2) to investigate the association between the three major measures of SEP—income, education, and occupation—and the prevalence of diabetes. Regression analyses were conducted to examine the degree to which sense of personal control and social support mediate the association between level of educational attainment and diabetes and to examine the contribution of each of the SEP measures to diabetes. After adjusting for age, obesity, sex, and race, respondents with less than a high school education had greater odds of having diabetes than those with a college degree or higher level of educational attainment, although the corresponding confidence interval contained the null value (OR = 1.2, 95% CI: 0.7, 2.0). Neither sense of control nor social support significantly mediated the association between education and diabetes. However, sense of control was associated with diabetes status (OR = 0.7, 95% CI: 0.5, 1.0). Compared with income and education, employment status was the most strongly associated measure of SEP with diabetes prevalence. After adjusting for age, obesity, sex, and race, respondents who were unable to work due to disability had fourfold greater odds of having diabetes than those who were employed full time (OR = 4.0; 95% CI: 1.9, 8.3). Adding income and/or education to the model did not improve the fit. Understanding the impact of socioeconomic factors on diabetes requires consideration of multiple measures of SEP as well as the psychosocial pathways through which SEP may influence diabetes. ^

Psychosocial and environmental predictors of calcium intake, physical activity and bone health among adolescent girls

Objectives. The purpose of this study was to identify the psychosocial and environmental predictors and the pathways they use to influence calcium intake, physical activity and bone health among adolescent girls. Methods. A secondary data analysis using a cross-sectional and longitudinal study design was implemented to examine the associations of interest. Data from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study collected in 2001-2003 were utilized for the analyses. IMPACT was a 1½ year nutrition and physical activity intervention study conducted among 718 middle-school girls in central Texas. Hierarchical regression modeling and Structural Equation Modeling (SEM) were used to determine the psychosocial predictors of calcium intake, physical activity and bone health at baseline. Hierarchical regression was used to determine if psychosocial factors at baseline were significant predictors of calcium intake and physical activity at follow-up. Data was adjusted for included BMI, lactose intolerance, ethnicity, menarchal status, intervention and participation in 7th grade PE/athletics. Results. Results of the baseline regression analysis revealed that calcium self-efficacy and milk availability at home were the strongest predictors of calcium intake. Friend engagement in physical activity, physical activity self-efficacy and participation in sports teams were the strongest predictors of physical activity. Finally, physical activity outcome expectations, social support and participation in sports teams were significant predictors of stiffness index at baseline. Results of the baseline SEM path analysis found that outcome expectations and milk availability at home directly influenced calcium intake. Knowledge and calcium self-efficacy indirectly influenced calcium intake with outcome expectations as the mediator. Physical activity self-efficacy and social support had significant direct and indirect influence on physical activity with participation in sports teams as the mediator. Participation in sports teams had a direct effect on both physical activity and stiffness index. Results of regression analysis for baseline predicting follow-up showed that participation in sports teams, self-efficacy, outcome expectations and social support at baseline were significant predictors of physical activity at follow-up. Conclusion. Results of this study reinforce the relevance of addressing both, psychosocial and environmental factors which are critical when developing interventions to improve bone health among adolescent girls. ^