Is cardiorespiratory fitness a moderator of the relationship between sugar-sweetened beverage consumption and insulin resistance in schoolchildren?

Purpose The aim of this study was to determine whether cardiorespiratory fitness (CRF) decreases the association between insulin resistance and sugar-sweetened beverage (SSB) consumption in a population-based sample of Spanish schoolchildren. Methods This is a cross-sectional study including 430 schoolchildren (51.4% girls), aged 8-12 years, from 10 schools in Cuenca (Spain). Blood samples were drawn to measure fasting insulin levels. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was also assessed. Data on SSB consumption were gathered using the Children's Eating Habits Questionnaire, which was completed by parents. The CRF level was determined by the 20 m Shuttle Run test and a curvilinear allometric model. Results Our conditional regression estimates showed that CRF moderated the association of SSB consumption on insulin levels or HOMA-IR. In children who had levels of CRF < 34.4 ml/kg/min ml/kg/min (for insulin levels) or < 33.6 ml/kg/min (for HOMA-IR), the association between SSB consumption and fasting insulin levels or HOMA-IR raised. Among children with CRF levels between 34.4 and 52.1 ml/kg/min (for insulin levels) or 33.6-55.4 ml/kg/min (for HOMA-IR), the association of SSB consumption on insulin level or HOMA-IR neither increased nor decreased. Among children with CRF levels > 52.1 ml/kg/min (for insulin levels) or > 55.4 ml/kg/min (for HOMA-IR), the association of SSB consumption on fasting insulin levels or HOMA-IR decreased. Conclusions Our results showed that certain levels of CRF moderate the association between SSB consumption and insulin resistance in a population-based sample of Spanish schoolchildren.