Markers of insulin resistance are associated with fatness and fitness in school-aged children: the European Youth Heart Study

Abstract

Aims/hypothesis Our aim was to examine the association between markers of insulin resistance and: (1) body fat and waist circumference, taking into account cardiorespiratory fitness in school-aged children; and (2) cardiorespiratory fitness at differing levels of body fat and waist circumference. Subjects and methods This was a cross-sectional study of 873 children aged 9.6±0.4 years from Estonia and Sweden. Weight, height and waist circumference were measured. Body fat was expressed as the sum of five skinfold thicknesses. Cardiorespiratory fitness was estimated by a maximal cycle-ergometer test. The studied markers of insulin resistance were fasting insulin and glucose, and homeostasis model assessment (HOMA). Results HOMA and fasting insulin were positively associated with body fat and waist circumference after adjusting for cardiorespiratory fitness, age, pubertal status and study location. HOMA and fasting insulin were negatively associated with cardiorespiratory fitness in children in the third (highest) tertile of body fat and waist circumference after controlling for sex, age, pubertal status and study location. Fasting glucose was negatively associated with cardiorespiratory fitness in children in the third (highest) tertile of waist circumference, but it was not associated when body fat was taken into account. Conclusions/interpretation In school-aged children, HOMA and fasting insulin are significantly associated with body fat and waist circumference. In addition, cardiorespiratory fitness explains a significant proportion of the HOMA and fasting insulin variance in those children with high levels of body fat and waist circumference. The findings suggest that the deleterious consequences ascribed to high fatness could be counteracted by having high levels of cardiorespiratory fitness.

Cardiorespiratory Fitness and Fatness Are Associated With Health Complaints and Health Risk Behaviors in Youth

“…This indicates that high levels of cardiorespiratory tness might overcome the deleterious effects of overweight-obesity. This nding is consistent with other studies that examined the combined in uence of tness and fatness on other health outcomes such as insulin resistance, 50 blood pressure, 51 and metabolic risk. 7,52 This implies that interventions to prevent states of unfavorable health pro les should focus not only on weight reduction but also on enhancing cardiorespiratory tness.…”

Insulin sensitivity at childhood predicts changes in total and central adiposity over a 6-year period

“…Although in previous cross-sectional studies we observed that total and central adiposity was associated with HOMA in children 21 and in adolescents, 8 the present longitudinal study did not support such associations. This finding concurs with the study by Johnson et al 6 in healthy children.…”

Physical fitness in childhood and adolescence: a powerful marker of health

“…We have shown that higher levels of cardiorespiratory fitness are inversely associated with a healthier cardiovascular profile in children and adolescents. 16,23,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] Results from the AVENA study indicate that high levels of cardiorespiratory fitness are associated with a more favorable metabolic profile (computed from age-and sex-specific standardized values of triglycerides, LDLc, HDLc and fasting glycemia) in both overweight and non-overweight Spanish adolescents ( Figure 3). 52 The same association was also found between cardiorespiratory fitness and the clustering of metabolic risk factors and individual CVD risk factors in Swedish and Estonian children and adolescents participating in the EYHS.…”

“…44,49,51,55 Regarding cardiorespiratory fitness and traits of pediatric type II diabetes, data from the Swedish and Estonian part of the EYHS indicate that cardiorespiratory fitness explains a significant proportion of the homeostasis model assessment, a surrogate of insulin resistance, and fasting insulin variance in those children with relatively high levels (that is, the highest tertile) of body fat and waist circumference. 49 Data from the same study population show that markers of total and abdominal adiposity are related to blood pressure in girls with low levels of cardiorespiratory fitness. 44 Further analysis revealed that girls with hypertension had higher fatness and lower fitness compared with girls with normal blood pressure.…”