Physical activity and fitness: Moderators of the stress-metabolic syndrome relationship

Childhood obesity and metabolic syndrome are viewed as critical public health concerns and efforts to attenuate these conditions have focused primarily on two behavioral factors, diet and physical activity. Recent research has shifted toward viewing these conditions as a result of the interactions between many antecedents that can influence the balance of energy intake and expenditure. One intriguing line of research implicates perturbations in the stress response system and the putative role that dysregulation may have on the development of obesity and metabolic syndrome. Researchers have observed relationships similar to those found in the adult literature when examining the links between health and a number of 'stress-related' variables in youth. An increased focus on psychosocial health determinants of metabolic heath such as stress is of particular interest, given the favorable relationship between physical activity and/or fitness and stress. This apparent beneficial relationship between physical activity and stress has led researchers to examine whether physical activity may have a moderating effect (i.e., effect modification) on the stress-metabolic syndrome relationship. Literature addressing this potential effect modification is sparse but promising.;This dissertation aimed to examine further the relationship between psychosocial health and metabolic health and investigate the potential moderation physical activity and health-related fitness may have on this relationship. We examined perceived stress, problem-focused coping levels, metabolic syndrome-related variables, physical activity levels, and health-related fitness variables in 126 middle school students in the 2010-2011 school year. Participants approximated the 75th percentile for BMI and gender differences were observed when examining systolic blood pressure, physical activity level as estimated by questionnaire, vigorous physical activity as estimated by accelerometer, and perceived stress. Results showed little influence of perceived stress or problem-focused coping associated with metabolic health as determined by a metabolic syndrome composite score and BMI. Likewise, a moderating influence of physical activity or fitness was not observed.;Results of this study suggest physical activity, stress, and problem-focused coping have little influence on the metabolic syndrome composite score or BMI in this sample. Although we did not observe our hypothesized relationships, the line of inquiry examining a moderating influence of physical activity and fitness on this relationship holds merit and should not be abandoned. Our study highlights the need for continued methodological refinement, particularly regarding assessment of psychosocial health indicators in this age group. A critical step in elucidating the relationship between stress and health in youth requires identification and concise descriptions of indices of psychosocial health that are most relevant to metabolic health. Identification of modifiable variables with influence that transcends multiple putative contributors to energy imbalance is particularly critical in children and adolescents where behaviors and attitudes are still developing and timely interventions could translate into long-term, positive health outcomes in adulthood.