Relation between plasma antioxidant vitamin levels, adiposity and cardio-metabolic profile in adolescents: Effects of a multidisciplinary obesity programme.

BACKGROUND & AIMS: In vivo and in vitro evidence suggests that antioxidant vitamins and carotenoids may be key factors in the treatment and prevention of obesity and obesity-associated disorders. Hence, the objective of the present study was to determine the relationship between plasma lipid-soluble antioxidant vitamin and carotenoid levels and adiposity and cardio-metabolic risk markers in overweight and obese adolescents participating in a multidisciplinary weight loss programme. METHODS: A therapeutic programme was conducted with 103 adolescents aged 12-17 years old and diagnosed with overweight or obesity. Plasma concentrations of α-tocopherol, retinol, ß-carotene and lycopene, anthropometric indicators of general and central adiposity, blood pressure and biochemical parameters were analysed at baseline and at 2 and 6 months of treatment. RESULTS: Lipid-corrected retinol (P < 0.05), ß-carotene (P = 0.001) and α-tocopherol (P < 0.001) plasma levels increased significantly, whereas lipid-corrected lycopene levels remained unaltered during the treatment. Anthropometric indicators of adiposity (P < 0.001), blood pressure (P < 0.01) and biochemical parameters (P < 0.05) decreased significantly, whereas fat free mass increased significantly (P < 0.001). These clinical and biochemical improvements were related to changes in plasma lipid-corrected antioxidant vitamin and carotenoid levels. The adolescents who experienced the greatest weight loss also showed the largest decrease in anthropometric indicators of adiposity and biochemical parameters and the highest increase in fat free mass. Weight loss in these adolescents was related to an increase in plasma levels of lipid-corrected α-tocopherol (P = 0.001), ß-carotene (P = 0.034) and lycopene (P = 0.019). CONCLUSIONS: Plasma lipid-soluble antioxidant vitamin and carotenoid levels are associated with reduced adiposity, greater weight loss and an improved cardio-metabolic profile in overweight and obese adolescents.