Fitness, fatness, and coronary heart disease risk in adolescents: the Northern Ireland Young Hearts Project

Abstract

. Purpose: The purpose of this study was to examine the independence and relative strengths of association between coronary heart disease (CHD) risk status and both body fatness and cardiorespiratory (C-R) fitness in 12-and 15-yr-old adolescents. Methods: The study cohort consisted of 1015 schoolchildren aged 12 and 15 yr (251 12-yr-old boys, 258 12-yr-old girls, 252 15-yr-old boys, and 254 15-yr-old girls), representing a 2% random sample of each population group. For each child, height, weight, sexual maturity (pubertal status), skin-fold thicknesses (4 sites), blood pressure (random zero sphygmomanometer), nonfasting serum total, and high density lipoprotein (HDL)-cholesterol and C-R fitness (20-m shuttle run; 20-MST) were determined under standardized conditions. Socioeconomic status and habitual physical activity were also determined from questionnaire information. Multiple regression analyses were carried out to examine relationships between five CHD risk factors, and fitness and fatness and to examine the relative strengths of fitness and fatness on CHD risk status, correcting for potential confounding variables. Results: Our main findings were: 1) Relationships between fatness and CHD risk factors are invariably stronger than between fitness and the same risk factors. For example, partially adjusted standardized regression coefficients for 12-yr-old boys revealed significant relationships between all five CHD risk factors and fatness, compared with three of five for fitness. The corresponding figures for 12-yr-old girls were three of five (fatness) and one of five (fitness). Broadly similar results were apparent for 15-yr-olds. 2) Although relationships between fitness and CHD risk factors do not survive further adjustment for fatness, the relationships between fatness and CHD risk are more robust and are unaffected by further adjustment for fitness. Conclusion: Our results indicate that the observed relationships between C-R fitness and CHD risk status in adolescents are mediated by fatness, whereas the observed relationships with fatness are independent of fitness. Primary prevention of CHD during childhood should therefore concentrate upon preventing or reversing undue weight gain.

Freiburg Intervention Trial for Obese Children (FITOC): results of a clinical observation study

“…In An outpatient program for obese children U Korsten-Reck et al addition, independent of age, they found higher HDL-C values in girls than in boys. The same trend was seen in Northern Ireland by Boreham et al, 23 who described a cohort of subjects between the ages 12 and 15 y. All these results are primarily explained by the influence of sex hormones in that age group.…”

Aerobic fitness, body mass index, and CVD risk factors among adolescents: the Québec family study

“…In contrast, Boreham et al 18 found that the relationships between aerobic fitness and CVD risk factors were not statistically significant after adjustment for fatness but the relationships between fatness and CVD risk factors remained significant after adjustment for aerobic fitness. Using logistic regression, Nielsen and Andersen 41 found that males and females classified with BMI425 kg m À2 and with low fitness had a greater likelihood of being classified as hypertensive compared to individuals of the same body size but with moderate or high fitness.…”

“…17 The results of previous studies have suggested that the relationship between aerobic fitness and CVD risk factors in youth is mediated by body fatness. 15,16 Furthermore, Boreham et al 18 concluded that the cardiovascular health of children may be better associated with fatness than aerobic fitness. To our knowledge, no reports have considered the interactions between aerobic fitness and BMI among adolescents, and their influence on CVD risk factors.…”

Association between Fitness, Different Indicators of Fatness, and Clustered Cardiovascular Diseases Risk Factors in Portuguese Children and Adolescents

“…Given that insulin resistance could be a predictor of obesity and cardiovascular risk factors [34], the findings of these studies could explain some of our results and suggest that maybe the insulin resistance could be the mediator link between CRF, obesity and clustered risk factors. If we assume that fatness is the main mediator of the relationship between clustered risk factors and CRF [35] we do not take in consideration the fact that insulin resistance could be the link behind this relation. Further, insulin sensitivity is mainly related to the muscle tissue, because a great portion of the carbohydrate is stored or burned in the muscle [36].…”