Who benefits from intervention in, as opposed to screening of, overweight and obese children?

Abstract

StEP TWO is a school- and family-based intervention consisting of extra lessons, healthy nutrition and physical education for overweight and obese children in primary schools, aimed at reducing body mass index by maintenance or reduction of weight, and improving motor abilities. We analysed differences in changes in anthropometric, cardiovascular and obesity parameters between children who underwent intervention, non-participants in intervention, and controls. Anthropometric data and waist circumference were recorded for 1678 children; body mass index and body mass index-standard deviation score were calculated. Blood pressure was measured after 5 minutes at rest. 121 overweight and obese children enrolled at 3 schools involved in programmes of intervention were invited to take part; 40 of them completed the programme from November 2003 to July 2004. Of these overweight children, 74 were invited, but did not take part. As controls, we enrolled 155 overweight and obese children from 4 other schools. After the programme, the children involved in intervention showed a lower increase in the body mass index (0.3 plus or minus 1.3 versus 0.7 plus or minus 1.2 kilograms per metre squared) and an approximately three times higher diminution of the body mass index-standard deviation score in comparison with their controls (-0.15 plus or minus 0.26 versus 0.05 plus or minus 0.27). Systolic blood pressure was significantly lowered by 9.5 plus or minus 19.6 millimetres of mercury in those involved in intervention, but increased in the control group by 0.5 plus or minus 16.5 millimetres of mercury. Among those invited but not participating, the increase of the body mass index (0.5 plus or minus 1.3 kilograms per metre squared) was less, and the reduction of the body mass index-standard deviation score (-0.09 plus or minus 0.31) and systolic blood pressure (-5.3 plus or minus 15.6 millimetres of mercury) was higher than in the control group. Overweight but not obese children seem to benefit from a screening examination alone. Early preventive measures in schools are necessary and effective for overweight and obese primary school children. The screening itself seems also to have a minor positive effect, especially for overweight children. Sustainability of the observed improvements over a longer period remains to be confirmed.