Bone Health of Obese Adolescents During Weight Loss
Condition: Pediatric Obesity
MeSH terms: Pediatric Obesity; Weight Loss
Study type: Interventional

Summary: 
      The long-term goal of this proposal is to understand the impact of obesity and obesity
      treatment on bone health during adolescence and how to preserve it. The recent pediatric
      obesity epidemic raises important clinical and public health questions about the effects of
      childhood-onset obesity and its treatment on bone health. Osteoporotic fractures are a major
      cause of morbidity and mortality in the aged, and peak bone mass (PBM), achieved shortly
      after puberty, is a key determinant of bone strength and lifetime fracture risk. Given the
      current obesity epidemic, obesity treatment during adolescence will continue to be necessary.
      The benefits of pediatric obesity treatment are unquestionable. However, the potential
      detrimental effects of weight loss on bone density and dimensions are not known in
      adolescents and are the focus of this proposal.

      This study will focus on the impact of pediatric-onset obesity and its treatment on bone
      health, using two approaches: comparing obese and non-obese adolescents and comparing obese
      adolescents before and after weight loss. We hypothesize that (a) compared to non-obese
      controls, obese adolescents have stronger bones, and that (b) bone strength of obese
      adolescents decreases during weight loss compared to usual care, which would suggest a need
      to promote bone health during successful weight loss in obese adolescents.
    

Detailed description: 
      Context: The childhood obesity epidemic raises important clinical and public health questions
      about the effects of both obesity and obesity treatment on bone development. Osteoporotic
      fractures are a major cause of morbidity and mortality in the aged. However, peak bone mass,
      achieved shortly after puberty, is the key determinant of lifetime osteoporotic fracture
      risks. The size and direction of effects of obesity and weight loss on bone health in
      childhood are unclear, partly because of bone ascertainment issues. Obese children and
      adolescents may have elevated fracture risks, contrary to expectations based on adult data.
      Objectives: Primary aims of the proposed study are to: 1) characterize and compare bone
      health of obese and non-obese adolescents using the most accurate methods available, and 2)
      investigate the impact of comprehensive behavior weight control program on the bone health of
      obese adolescents. Study Design: Aim 1 will use a case-control design to compare bone status
      measures of 88 obese adolescents (ages 10 to 14 years), to be recruited for a randomized
      obesity treatment trial, with the same measurements of 51 contemporary non-obese control
      adolescents. For Aim 2, the 88 obese adolescents will be enrolled in a 12-month randomized
      trial, with 1:1 assignment, of a comprehensive behavioral weight control program vs.
      individualized nutrition education (usual care). This randomized trial is the object of this
      registration. Study Measures: For both aims the primary outcome will be bone strength,
      estimated by stress-strength index, and measured by peripheral quantitative computerized
      tomography (pQCT) at the tibia, a weight-bearing site.
    

Intervention name(s): Comprehensive behavioral weight control program; Individual 12-month nutrition education program
Intervention type(s): Behavioral; Other
Intervention description(s): Participants will meet weekly for 12 weeks, then every other week for 12 weeks, and once a month thereafter through week 52. Adolescents and parents will receive manuals that provide lessons and homework assignments for each meeting. The program for the first 22 weeks includes the following topics: 1) the causes of obesity; 2) components of healthy nutrition; 3) self-monitoring of calories, physical activity, and inactivity; 4) stimulus control procedures; 5) coping with high-risk social or psychological situations that trigger excess eating; 6) increasing physical activity; and 7) minimizing inactivity. At each session, participants will submit their self-monitoring diaries and completed homework. Incentives for completion of self-monitoring tasks are an integral part of the behavior modification program and a small gift certificate will be given to subjects for successful completion at each intervention session.; The other half of the participants (44 subjects) will be randomized to this arm of the intervention (usual care), which will also start in five waves. In contrast to the comprehensive behavioral weight control program, the nutrition education program will take place through individual appointments with a clinical dietician to reflect usual care and mimic the present approach used for the treatment of obese adolescents at the Children's Hospital of Philadelphia (CHOP) Nutrition Consultation. Parents will be required to take part in the consultations. The first consultation will last 60 minutes and the following consultations of 30 minutes will take place once a month for the first six months, then every other month for the second six months, as is the usual practice in our clinical setting.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Child; Obesity