Body composition, physical fitness and cardiovascular risk factors in 9-year-old children

The independent associations of body composition and physical fitness components with cardiovascular disease (CVD) risk factors in childhood are not fully understood. Thus, this cross-sectional study examined the independent associations of body composition and physical fitness with CVD risk factors in Swedish 9-year-old children (n = 411). Unadjusted linear regression analyses showed that body mass index (BMI), % fat mass and fat mass index were all positively associated with systolic and diastolic blood pressure, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Metabolic Syndrome (MetS) score (all beta >= 0.229, P <= 0.001). These associations were virtually unaffected by adjustments for basic covariates (child's age and sex, maternal educational level and maternal BMI), fat-free mass and physical fitness. Fat-free mass index had generally weak associations with CVD risk factors and no associations were statistically significant after adjustments (all P > 0.27). Greater cardiorespiratory fitness and motor fitness were associated with lower HOMA-IR and MetS score in unadjusted models (all beta <= - 0.158, P <= 0.039) but not after adjustments for basic covariates and body composition. These findings indicate that cardiovascular health promotion in childhood may focus on the maintenance of a healthy fat mass.

Automated summary

The study found a positive association between fat mass and cardiovascular disease risk factors in children, while fat-free mass had weaker associations. Additionally, cardiorespiratory fitness and motor fitness were related to CVD risk factors, but these associations were influenced by basic covariates and body composition adjustments.