Objective To assess the influence of a 12-week training programme on plasmatic levels of allantoin, an in vivo marker for oxidative stress, in adolescents with Down syndrome. This finding would be of great interest, since oxidative damage has been proposed as a pathogenic mechanism of several pathologies in this population.

Materials To reach this goal, 31 male adolescents with Down syndrome (16.3 (1.1) years; 155.2 (5.7) cm; 70.8 (4.5) kg) performed a 12-week training programme, three sessions per week, consisting of warm-up (15 min) followed by a main part (20–35 min (increasing 5 min each 3 weeks)) at a work intensity of 60–75% of peak heart rate (increasing by 5% each 3 weeks) and then a cool-down period (10 min). According to previous studies, it should be emphasised that the maximal heart rate for individuals with Down syndrome was predicted by the equation HRmax = 194.5–(0.56 age). The control group included seven age-, sex- and BMI-matched adolescents with trisomy 21 that did not perform any training programme. The levels uric acid and allantoin were assayed in plasma by HPLC. This protocol was approved by an institutional ethics committee.

Results When compared with baseline, plasmatic levels of allantoin were decreased significantly (22.09 (1.62) vs 18.74 (1.38) μmol/l; p<0.001) after being exercised. Furthermore, the allantoin/uric acid ratio was decreased significantly (0.071 (0.006) vs 0.059 (0.004); p<0.05). On the contrary, no changes were reported in controls.

Conclusion A 12-week aerobic programme significantly reduced oxidative damage expressed in terms of plasmatic allantoin content in adolescents with Down syndrome. Further studies on this topic are required.