An investigation into cardiometabolic risk in children and adolescents

Abstract

The principle aim of this work was to provide an insight into the prevalence of the metabolic syndrome (MetS) in children and adolescents and to examine the associations of body composition measures, cardiorespiratory fitness (CRF), and physical activity with cardiometabolic risk. The combined association of adiposity and CRF on cardiometabolic risk in youths is also explored, as is the association of CRF with potentially modifiable variables, such as physical activity. This work has shown that, dependent on the definition employed, MetS may be present in 2.3% to 9.8% of children and adolescents in Bedfordshire, UK. When applying modified Adult Treatment Panel III definitions (Cook et al. 2003; de Ferranti et al. 2004), the condition was significantly more prevalent in overweight compared to non-overweight youths. Backward regression analyses identified that only body mass index (BMI) explained significant amounts of variance in clustered cardiometabolic risk, although being overweight according to internationally proposed cut points for BMI, waist circumference (WC), and waist-to-height ratio conferred participants to increased risk compared to their non-overweight counterparts. Clustered risk was also elevated in children and adolescents with low levels of CRF compared to those with high levels, whereas time spent in moderate-to-vigorous physical activity and vigorous physical activity (VPA) held no association. When stratified into groups according to level of fatness (BMI z-score) and CRF, those with high fatness/low CRF generally exhibited the most unfavourable cardiometabolic risk profiles. Cardiometabolic risk was higher in the high fatness/low CRF group compared to those with low fatness/low CRF and low fatness/high CRF when excluding WC from the score, and those with low fatness/low CRF when including WC in the score. Multiple regression and ANCOVA revealed that increased visceral fatness (indirectly measured using WC) was associated with reduced CRF, while increased time spent in VPA was associated with elevated CRF. These data suggest that BMI may be the best simple measure of obesity to employ when exploring adiposity-related cardiometabolic in children and adolescents. In addition, results from this iv investigation indicate that low CRF and overweight/obesity may have deleterious effects on the cardiometabolic health of children and adolescents and that interventions to reduce risk may target decreases in fatness and improvements in CRF and VPA as standard.

Date of Award	Feb 2012
Original language	English
Awarding Institution	University of Bedfordshire
Supervisor	Steve Kozub (Second supervisor)