Peak oxygen uptake cut-points to identify children at increased cardiometabolic risk - The PANIC Study.

We aimed to develop cut-points for directly measured peak oxygen uptake ( ) to identify boys and girls at increased cardiometabolic risk using different scaling methods to control for body size and composition. Altogether 352 children (186 boys, 166 girls) aged 9-11 years were included in the analyses. We measured V̇O directly during a maximal cycle ergometer exercise test and lean body mass (LM) by bioelectrical impedance. We computed a sex- and age-specific cardiometabolic risk score (CRS) by summing important cardiometabolic risk factors and defined increased cardiometabolic risk as >1 standard deviation above the mean of CRS. Receiver operating characteristics curves were used to detect V̇O cut-points for increased cardiometabolic risk. Boys with V̇O <45.8 mL kg body mass (BM)  min (95% confidence interval [CI] = 45.1 to 54.6, area under the curve [AUC] = 0.86, P < 0.001) and <63.2 mL kg LM  min (95% CI =52.4 to 67.5, AUC = 0.65, P = 0.006) had an increased CRS. Girls with V̇O <44.1 mL kg BM  min (95% CI = 44.0 to 58.6, AUC = 0.67, P = 0.013) had an increased CRS. V̇O scaled by BM and LM derived from log-linear allometric modeling poorly predicted increased cardiometabolic risk in boys and girls. In conclusion, directly measured <45.8 mL kg BM  min among boys and <44.1 mL kg BM  min among girls were cut-points to identify those at increased cardiometabolic risk. Appropriately controlling for body size and composition reduced the ability of cardiorespiratory fitness to identify children at increased cardiometabolic risk.