Clinical trial NCT00756899: Vitamin D Deficiency and Low Bone Mineral Content in Children
Official title: The Relationship Between Vitamin D Deficiency and Low Bone Mineral Content in Children
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Vitamin D Deficiency
Obesity
Keywords: Vitamin D deficiency, insulin resistance, obesity, bone
Lead sponsor: University of Massachusetts, Worcester
Sponsor class: OTHER
First posted: 2008-09-22
Enrollment: 45
Sex: ALL
Minimum age (years): 3
Maximum age (years): 12
Standard ages: CHILD
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Prepubertal children

Brief summary: The Vitamin D study is designed to investigate the effect of body fat mass on vitamin D levels in children. Earlier studies have shown that individuals with increased fat mass may have low vitamin D levels.

Our specific hypothesis states that children with increased fat mass will have lower blood levels of vitamin D when compared to non-obese children.Since vitamin D is the primary hormone for bone mineralization in humans, low levels of vitamin D could lead to decreased bone mineral content in these children.

Detailed description: Fifty prepubertal male and female children of ages between 3-12 years will participate in this study. Of these, 25 obese children will be enrolled in the study group, and 25 non-obese children will serve as controls.

All subjects will fill out a comprehensive mineral intake questionnaire as part of the study to ensure adequate calcium intake prior to the study.

All subjects will collect a first morning urine sample for calcium, creatinine, and NTX.

Fasting blood samples will be drawn for the following analytes: 25-hydroxyvitamin D, 1, 25-dihydroxyvitamin D, intact PTH, calcium, phosphorus, magnesium, osteocalcin, insulin, c-peptide, fasting blood glucose, leptin, and adiponectin.

Bone Mineral Content will be evaluated in 16 obese subjects with vitamin D level of \< 30 nmol/L.

Eligibility criteria: Inclusion Criteria:

* General: Prepubertal children (males, with testicular volume of ≤ 3 cc, and girls with Tanner 1 breast) of ages 7-11 years will be enrolled in the study.
* Study group: Subjects with a BMI of \> 95th percentile for age and sex.
* Control group: All control subjects will have a BMI of \< 85th percentile for age and sex.

Exclusion Criteria:

* known metabolic or genetic diseases resulting in obesity such as severe hypothyroidism, pseudohypoparathyroidism, or Cushing's disease
* diabetes mellitus
* subjects on lipid lowering medications
* subjects on medications known to impact body weight or calcium homeostasis
* subjects with a history of recent significant weight loss or gain

Primary outcomes:
measure: Bone mineral content
timeFrame: Baseline
Secondary outcomes:
Other outcomes:
Locations:
city: Worcester
country: United States
facility: University of Massachusetts Medical School
state: Massachusetts
Study officials:
affiliation: University of Massachusetts, Worcester
name: Benjamin U Nwosu, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Massachusetts, Worcester
name: Carol A Cicarrelli, RN
role: STUDY_DIRECTOR
References: