Hindawi Publishing Corporation International Journal of Pediatrics Volume 2010, Article ID 580897, 5 pages doi:10.1155/2010/580897 Clinical Study Relationships of Cardiorespiratory Fitness with Metabolic Risk Factors, Inﬂammation, and Liver Transaminases in Overweight Youths Dominique Bougle´ ,1, 2 Gautier Zunquin,2 Bruno Sesboue¨,3 and Jean-Pierre Sabatier2 1 Service de P´ediatrie, Centre Hospitalier de Bayeux, 14400 Bayeux, France 2 Service de P´ediatrie, CHU de Caen, 14000, Caen, France 3 Institut R´egional de M´edecine du Sport, CHU de Caen, 14000, Caen, France Correspondence should be addressed to Dominique Bougle´, dbougle@wanadoo.fr Received 9 January 2010; Revised 4 May 2010; Accepted 2 June 2010 Academic Editor: Lars B. Andersen Copyright © 2010 Dominique Bougle´ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The aim of this study was to assess the relationships of fatness and ﬁtness with metabolic risk factors, including liver transaminases and inﬂammation in obese youth, taking in account gender, age, and pubertal stage. 241 children were studied (135 girls), age 11.9 ± 2.2 years (x ± SD), Body Mass Index z score 5.4 ± 2.7. For girls, VO2max was signiﬁcantly associated with insulin (P = .001), Insulin resistance (HOMA-IR) (P = .005), and ALT (P = .012); a relationship was displayed between ﬁbrinogen and age and % fat mass (FM) (P = .008); for boys, relationships were found between VO2max and diastolic blood pressure and triglycerides; independent associations were also found between age and insulin, HOMA-IR and HDL cholesterol; ﬁbrinogen and sedimentation rate were related (P ≤ .004) with %FM. Their relationships are observed from young age and increase with the continuous increase of factors. This supports the need to treat overweight as soon as it is detected; improving CRF is one of the ways which could be used to prevent the complications of obesity. 1. Introduction Overweight is associated with an increased cardiovascular risk, even in youth [1, 2]. It is also associated with a decreased cardiorespiratory ﬁtness (CRF), which is liable to contribute to obesity itself. Several large reports clearly show a relationship between decreased CRF and the occurrence of metabolic risk factors in overweight adults and youth. Whether ﬁtness and fatness have independent inﬂuences on metabolic risk, however, is not fully explained [3, 4]. Some of the studies addressed only one individual factor [5–9] but most of them clustered these risks in “metabolic syndrome” (MS) [8, 10–13]; MS usually associates with obe- sity, dyslipoproteinemia (raised triglyceride and/or reduced HDL-cholesterol levels), hypertension, and insulin resistance or diabetes, but variables included in the MS and their relative weight vary among deﬁnitions; the last of them was given by the International Diabetes Federation [14]. Nonalcoholic fatty liver disease is frequently associated with MS, so that it has been proposed as a core feature of it [15, 16]. In addition inﬂammation is never included in the criteria of MS, while it seems to be involved in the development of its consequences [1, 17]. The value of MS concept itself is still debated [18]. A recent WHO Expert Consultation came to the conclusions that it is not a useful diagnostic or management tool [19]. The present study assessed the respective relationships of CRF and fatness on individual components of MS, including liver transaminases as a surrogate of nonalcoholic fatty liver disease [15, 16]; ﬁbrinogen and sedimentation rate were added as markers of inﬂammation; CRF was measured by determining the maximal oxygen consump- tion (VO2max); the marker of overweight was fat mass, instead of BMI, because this latter one is a less valid measurement of body fatness in children and does not discriminate between muscle and fat [20] and it has been