Decline in physical fitness from childhood to adulthood associated with increased obesity and insulin resistance in adults

Abstract

Objective: To examine how child and adult fitness are associated with adult obesity and insulin resistance. Research Design and Methods: Prospective cohort study. Setting: Australia. Participants: A follow-up cohort of 647 adults in 2004-6 who were participants of the Australian Schools Health and Fitness Survey in 1985 (aged 9 to 15 years) who had an anthropometry and cardiorespiratory fitness assessment. Outcome measures: Insulin resistance was defined as a HOMA index above the 75th sex-specific percentile. Adults with a BMI 30kg/m2 were termed obese. Results: Lower levels of child cardiorespiratory fitness were associated with increased odds of adult obesity (adjusted OR per unit increase = 3.0, 95% CI: 1.6 to 5.6) and insulin resistance (adjusted OR = 1.7, 95% CI: 1.1 to 2.6). A decline in fitness level between childhood and adulthood was associated with increased obesity (adjusted OR = 4.5, 95% CI: 2.6 to 7.7) and insulin resistance (adjusted OR = 2.1, 95% CI: 1.5 to 2.9) per unit decline. Conclusions: A decline in fitness from childhood to adulthood, and by inference a decline in physical activity, is associated with obesity and insulin resistance in adulthood. Programs aimed at maintaining high childhood PA levels into adulthood may have potential for reducing the burden of obesity and type 2 diabetes in adults.