Abstract P089: Fitness and Fatness Are Both Associated With Cardiometabolic Health in 8-10 Year Old New Zealand Children

Abstract

Introduction: In adults, low cardiorespiratory fitness (CRF) and overweight-obesity are associated with greater cardiometabolic disease risk. However, the association between measures of CRF and overweight-obesity upon cardiometabolic risk in youth, particularly pre-adolescents, is less clear. Further, previous studies in children have predominantly examined the relationships between CRF and overweight-obesity upon individual cardiometabolic risk factors. The clustering of cardiometabolic risk factors has been recognized for over two decades, including in young children. Hypothesis: We tested the null hypothesis of no association between clustered cardiometabolic risk factors and high CRF or overweight-obesity. Methods: This cross-sectional study recruited 392 children (50% F) aged 8-10 years from three representative sample sites across New Zealand. Overweight-obesity was classified according to 2007 WHO criteria for Body Mass Index. CRF was estimated using a shuttle run test, and high CRF was categorized as a maximum oxygen uptake exceeding 35 ml/kg/min in girls, and 42 ml/kg/min in boys. Eleven traditional and novel cardiometabolic risk factors were measured: peripheral blood pressures, central systolic blood pressure, heart rate, augmentation index, fasting total cholesterol, high density lipoproteins, low density lipoproteins, triglycerides, serum glucose, and glycosylated haemoglobin. Principal component analysis identified underlying cardio-metabolic factors, and a 2-way (high fitness, overweight-obese) analysis of co-variance was used to determine associations between cardio-metabolic risk factors with fitness and overweight-obesity. Covariates were: age, sex, ethnicity, socio-economic status. Results: Principle component analysis revealed four underling factors: blood pressure, cholesterol, vascular, and carbohydrate-metabolism. Using these factors, a cumulative risk score was also calculated. Only high CRF (P=0.001, Eta=0.028) was significantly associated with the blood pressure factor. Only overweight-obesity associated with vascular (P=0.010, Eta=0.018) and carbohydrate-metabolism (P=0.005, Eta=0.021) factors. Neither high fitness (p=0.728) nor overweight-obesity (P=0.121) significantly associated with cholesterol. For the cumulative risk score, there was an interaction effect (P=0.038, Eta=0.012). High CRF improved cardiometabolic risk in overweight-obese children (P=0.006, Eta=0.02), but not in normal weight children. Conversely, being overweight-obese increased cardiometabolic health risk in children with low fat levels (P<0.001, Eta=0.039), but not in high fit children. Conclusions: In pre-adolescent children, fitness and fatness associate with different cardio-metabolic risk. With regards to overall cardio-metabolic risk, high fitness may protect against overweight-obesity.