Exercise-induced oxidative stress in overweight adolescent girls: roles of basal insulin resistance and inflammation and oxygen overconsumption

doi:doi:10.1038/ijo.2009.49

International Journal of Obesity (2009) 33, 447–455; doi:10.1038/ijo.2009.49

Exercise-induced oxidative stress in overweight adolescent girls: roles of basal insulin resistance and inflammation and oxygen overconsumption

H Youssef¹, C Groussard¹, J Pincemail², E Moussa³, C Jacob³, S Lemoine¹, M Zind³, J-O Defraigne², J Cillard¹, P Delamarche¹ and A Gratas-Delamarche¹

¹Laboratory 'Mouvement Sport Santé' (EA1274), University of Rennes 2, ENS Cachan, UFR-APS, Rennes Cedex, France
²Department of Cardiovascular surgery and CREDEC, B35 Sart Tilman hospital, University of Liège - CHU, Liège, Belgium
³Laboratory 'Physiologie et Biomécanique de la Performance Motrice', University of Balamand, Tripoli, Lebanon

Correspondence: Dr H Youssef, Laboratory 'Mouvement Sport Santé' (EA1274). University of Rennes 2, ENS Cachan. UFR-APS. Avenue Charles Tillon CS 24414, Rennes Cedex 35044, France. E-mail: hala.youssef@gmail.com

Received 19 June 2008; Revised 3 January 2009; Accepted 2 February 2009.

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Abstract

Hypothesis:

Basal insulin resistance (IR) and inflammation exacerbate post-exercise oxidative stress (OS) in overweight adolescent girls.

Design:

Cross-sectional study, effect of incremental ergocycle exercise until exhaustion on OS markers.

Participants:

Normal-weight (control) (n=17, body mass index (BMI): 20–24.2 kg/m²) and overweight adolescent girls (n=29, BMI: 24.1–36.6 kg/m²).

Measurements:

Dietary measurement, physical activity assessment (validated questionnaires), fat distribution parameters (by dual-energy X-ray absorptiometry and anthropometry) and maximal oxygen consumption ( Vdot O_2peak). Blood assays include the following: (1) at fasting state: blood cell count, lipid profile, and IR parameters (leptin/adiponectin ratio (L/A), homeostasis model assessment of IR, insulin/glucose ratio; (2) before exercise: inflammation and OS markers (interleukin-6 (IL-6), C-reactive protein (CRP), myeloperoxidase (MPO), reduced glutathione/oxidized glutathione ratio (GSH/GSSG), 15 F₂ alpha -isoprostanes (F₂-Isop), lipid hydroperoxides (ROOH), oxidized low-density lipoprotein (ox-LDL)) and antioxidant status (superoxide dismutase (SOD), glutathione peroxidase (GPX), vitamin C, alpha -tocopherol and beta -carotene); and (3) after exercise: inflammation and OS markers.

Results:

At rest, overweight girls had a deteriorated lipid profile and significantly higher values of IR parameters and inflammation markers, compared with the control girls. These alterations were associated with a moderate rest OS state (lower GSH/GSSG ratio, alpha -tocopherol/total cholesterol (TC) ratio and GPX activity). In absolute values, overweight girls exhibited higher peak power output and oxygen consumption ( Vdot O_2peak), compared with the control girls. Exercise exacerbated OS only in the overweight group (significant increase in F₂-Isop, ROOH and MPO). As hypothesized, basal IR and inflammation state were correlated with the post-exercise OS. However, the adjustment of F₂-Isop, ROOH and MPO variation per exercise Vdot O₂ variation canceled the intergroup differences.

Conclusion:

In overweight adolescent girls, the main factors of OS, after incremental exhaustive exercise, are not the basal IR and inflammation states, but oxygen overconsumption.

Keywords:

adolescent girls, exercise, inflammation, insulin resistance, oxidative stress

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Original Article