[1] Wilhelmina Childrens Hosp, Child Dev & Exercise Ctr, NL-3508 AB Utrecht, Netherlands
[2] Wilhelmina Childrens Hosp, Dept Pediat, NL-3508 AB Utrecht, Netherlands
[3] Wilhelmina Childrens Hosp, Dept Orthoped, NL-3508 AB Utrecht, Netherlands
[4] Univ Med Ctr Utrecht, Clin Hlth Sci, Utrecht, Netherlands
[5] Maastricht Univ, Sch Publ Hlth & Primary Care CAPHRI, Dept Epidemiol, Maastricht, Netherlands
[6] Univ Groningen, Univ Med Ctr Groningen, Dept Pediat, Pediat Endocrinol Subdiv, Groningen, Netherlands