Physical Fitness as a Predictor of Cardiovascular Disease Risk Factors in 6- to 7-Year-Old Danish Children: The Copenhagen School-Child Intervention Study

Abstract

The aim of this study was to investigate whether risk factors for cardiovascular disease cluster in 6- to 7-year-old children and whether low physical fitness is a predictor of risk factor clustering. The study included 369 boys (6.8 ± 0.4 years) and 327 girls (6.7 ± 0.4 years). VO2max was directly measured during a treadmill test. The ratio of total cholesterol to high-density cholesterol, triglyceride levels, the ratio of insulin to glucose, systolic blood pressure, and the sum of four skinfolds were selected as risk factors. A child was considered at risk for individual factors if he or she had values in the least favorable quartile. The number of children with more than three cardiovascular disease cluster risk factors was not significantly different from a binominal distribution. This lack of clustering could be a result of the fact that these young children have not yet developed insulin resistance. Children in the lowest quartile of fitness had an odds ratio of 2.1 (CI: 1.0–4.4) for having three or more risk factors compared with the most fit. This is interesting with regard to prevention because it indicates that an intervention involving increased physical activity might postpone or even prevent the development of risk factors.