Background Fatness and fitness both influence cardiometabolic risk. Objective The purpose of this study was to investigate whether childhood fatness and increasing fatness from childhood to adolescence are associated with cardiometabolic risk during adolescence and how fitness affects this association. Subjects and methods Of 565 adolescents (283 boys and 282 girls) from the TRacking Adolescents Individual Life Survey (TRAILS) data on anthropometric parameters (age 11 and 16), metabolic parameters and fitness (age 16) were available. BMI and skinfolds were used as measures for fatness. Increasing fatness was calculated by subtracting Z-scores for fatness at age 11 from Z-score fatness at age 16. Cardiometabolic risk was calculated as the average of the standardized means of mean arterial pressure, fasting serum triglycerides, HDL-cholesterol, glucose, and waist circumference. Insulin resistance was calculated by HOMA-IR. Fitness was estimated as maximal oxygen consumption (VO2max) during a shuttle run test. Results Boys showed a higher clustered cardiometabolic risk when compared to girls (P<0.01). Childhood fatness (age 11) and increasing fatness were independently associated with cardiometabolic risk during adolenscence. In boys, high fitness was related to a reduced effect of increasing fatness on clustered cardiometabolic risk. Childhood fatness, increasing fatness and fitness were independently associated with HOMA-IR. Moreover, in boys this association was dependent of fatness. Conclusions Childhood fatness and increasing fatness are associated with increased cardiometabolic risk and HOMA-IR during adolescence, but a good fitness attenuates this association especially in fat boys.
Objective: To assess the period during infancy and childhood in which growth is most associated with adolescent adiposity and the metabolic syndrome (MS) and whether this differs depending on maternal smoking during pregnancy. Study design: A longitudinal population-based cohort study among 772 girls and 708 boys. Results: Weight gains between ages 2-4 years and ages 4-7 years were most strongly associated with higher body mass index (BMI), sum of skinfold measurements, body fat percentage, and waist circumference at age 16. A one SD increase in weight between ages 2-4 and 4-7 years was associated with increases in outcome measures of +0.82 to +1.47 SDs (all P < .001), and with a less favorable MS score. In children whose mothers smoked during pregnancy, the association of relative weight gain during ages 2-4 years with adolescent BMI was stronger than in children whose mothers did not smoke. For adolescent BMI, the increase was 0.42 SD higher (P = .01). This was similar for the other adiposity measures. Conclusions: Large relative increases in weight from ages 2 to 7 years are associated with adolescent adiposity and MS. This is more pronounced in adolescents whose mothers smoked during pregnancy.