Weight loss and sleep-disordered breathing in childhood obesity: effects on inflammation and uric acid.

Sleep-disordered breathing (SDB) is prevalent in childhood obesity. It may be an independent risk factor for the metabolic syndrome. Possible mechanisms are inflammation and oxidative stress. Adenotonsillectomy in childhood obesity is associated with a high recurrence rate and risk of postoperative weight gain. Therefore, this study assessed the effects of SDB on inflammation and oxidative stress in childhood obesity before and after weight loss. We included 132 obese subjects between 10 and 18 years consecutively. Median age was 15.4 years (10.1-18.0). Mean BMI z-score was 2.72 ± 0.42. Leukocytes and differentiation, high sensitivity C-reactive protein (hs-CRP), and uric acid (UA) were determined at baseline and subjects underwent a sleep assessment. SDB was diagnosed in 39%. Linear regression analysis showed an association between UA(log) and oxygen desaturation index(log) (ODI(log)) (r = 0.20; P = 0.03), between leukocytes(log) and respiratory disturbance index(log) (RDI(log)) (r = 0.23; P = 0.01), and between lymphocytes(log) and RDI(log) (r = 0.19; P = 0.04). Follow-up was organized after 4-6 months of treatment. Median decrease in BMI z-score was 32%. Laboratory measurements were repeated. Subjects with SDB at baseline underwent a second sleep study. Of these 49 subjects, 12 showed residual SDB. This corresponds with a treatment success rate of 71%. Unlike changes in inflammatory markers, improvements in UA were associated with improvements in RDI and ODI (respectively: r = 0.44; P = 0.007, r = 0.41; P = 0.01). In conclusion, weight loss is effective in treating obese children with SDB. At baseline, a link exists between inflammation and SDB. Oxidative stress is reflected by UA at baseline and the concentration decreases after treatment according to improvements in SDB.

Role of physical activity and eating behaviour in weight control after treatment in severely obese children and adolescents.

AIM: To investigate the role of physical activity and eating behaviour in weight control 1.5 y after a weight-reduction programme in severely obese children. METHODS: Forty-seven children (13.4 +/- 2.1 y) were measured 1.5 y after the completion of a 10-mo residential treatment programme. Stature and body mass were measured; physical activity, fat and fibre intake, and self-efficacy in relation to physical activity and healthy eating behaviour were assessed using validated structured interviews. The total sample was divided into four subgroups according to unhealthy versus healthy physical activity and eating behaviour at follow-up. RESULTS: One-and-a-half years after treatment, subjects had regained 34 +/- 19% overweight, but were on average still 20 +/- 19% less overweight than before treatment (p < 0.001). The four subgroups did not differ in level of overweight at the beginning or end of treatment. At follow-up, there was a significant difference in overweight between the four subgroups (p < 0.05). The least healthy group (unhealthy physical activity and unhealthy eating behaviour) had a significantly higher level of overweight 1.5 y after treatment (183 +/- 36%) in comparison with the other groups (unhealthy physical activity and healthy eating: 150 +/- 21%; healthy physical activity and unhealthy eating: 156 +/- 14%; healthy physical activity and healthy eating: 138 +/- 16%) (p < 0.05), whilst the healthiest group showed the lowest level of overweight after treatment when compared to the other groups (p < 0.05). CONCLUSION: Results suggest that both physical activity and nutritional habits play an important role in weight maintenance after initial weight loss in obese children and that one healthy behaviour can not compensate for another unhealthy behaviour.

Changes in fat mass, fat-free mass and aerobic fitness in severely obese children and adolescents following a residential treatment programme.

UNLABELLED: The purpose of this study was to describe changes in fat mass (FM), fat-free mass (FFM) and aerobic fitness in severely obese children and adolescents during residential treatment in the Medical Paediatric Centre Zeepreventorium. Treatment consisted of moderate dietary restriction, physical activity and psychological support. This study was a clinical observation of 20 severely obese children and adolescents (8 boys and 12 girls, aged 15.4+/-1.8 years) who completed the 10-month residential programme. Height, weight, FM, FFM and aerobic fitness was measured four times during the intervention: at baseline, 11 weeks, 24 weeks and at 33 weeks (at the end of the programme ). The mean decrease in level of overweight was 46% (P<0.001), with a mean loss of 8.9% FM (P<0.001). Submaximal performance (PWC150) improved from 123+/-35 Watt to 152+/-37 Watt (P<0.001). Maximal performance levels increased (performance time: from 14+/-2.9 min to 15.3+/-3.5 min, peak power: from 186+/-38 Watt to 205+/-45 Watt, P<0.01) without an improvement in absolute VO(2 peak). CONCLUSION: A moderate dietary restriction in combination with physical activity and psychological support in severely obese children and adolescents is effective in decreasing body fat and improving physical performance. Further research is needed to evaluate the longer-term effects of such a programme.