Sir,

On behalf of my colleagues, I thank Dr Lehn for his letter. We are delighted with the interest he has shown in our work. Because of the importance of his question, we have calculated the effect of intervention in the group of obese and overweight children. Of 35 children undergoing intervention, 5 were classified as hypertensive, accepting the limitation that their blood pressure was measured only once. After intervention, only 1 child remained hypertensive. No significant differences were found compared with the control group.

The correlation in the group of children undergoing intervention and their controls showed a weak significant correlation between reduction of the body mass index and reduction of diastolic blood pressure (r = 0.214; p = 0.005), but not the systolic blood pressure. After separating the two groups, the positive correlation was stronger, and remained only found in the group undergoing intervention (r = 0.518; p = 0.001 versus r = 0.105; p = 0.232 in the controls).

Our purpose in the study reported was to demonstrate the effect of the StEP Two programme on blood pressure in general. It is inappropriate to draw further conclusions at this stage. Serial and systematic follow-up data is warranted to define the effect on obese and hypertensive children.