The relationship of dietary and lifestyle factors to bone mineral indexes in children.
OBJECTIVE
To identify factors related to children's bone mineral indexes at age 8 years, and to assess bone mineral indexes in the same children at ages 6 and 8 years.


METHODS
Bone mineral content (BMC [g]) and bone mineral density (BMD; calculated as g/cm 2 ) were measured by dual-energy x-ray absorptiometry (DEXA) in children and their mothers when the children were 8 years of age. A subset of children had an earlier DEXA assessment at age 6 years. Children's dietary intake, height, weight, and level of sedentary activity were assessed as part of a longitudinal study from ages 2 months to 8 years.


METHODS
Fifty-two healthy white children (25 male, 27 female) and their mothers. Main outcome measures Children's total BMC and BMD at age 8 years.


METHODS
Correlations and stepwise multiple regression analyses.


RESULTS
Factors positively related to children's BMC at age 8 years included longitudinal intakes (ages 2 to 8 years) of protein, phosphorus, vitamin K, magnesium, zinc, energy, and iron; height; weight; and age ( P < or = .05). Factors positively related to children's BMD at age 8 years included longitudinal intakes of protein and magnesium ( P < or = .05). Female sex was negatively associated with BMC and BMD at age 8 years ( P < or = .05). Children's bone mineral indexes at ages 6 and 8 years were strongly correlated ( r =0.86, P < .0001 for BMC; r =0.92, P <.0001 for BMD).


CONCLUSIONS
Because many nutrients are related to bone health, children should consume a varied and nutrient-dense diet.
Bounds
Wendy
W
Department of Nutrition and Food Systems, University of Southern Mississippi, 118 College Drive, Hattiesburg, MS 39406, USA. Wendy.Bounds@usm.edu
Skinner
Jean
J
Carruth
Betty Ruth
BR
Ziegler
Paula
P
D015502:Absorptiometry, Photon / Q000379:methods; D000367:Age Factors; D001827:Body Height; D001835:Body Weight; D015519:Bone Density / Q000502:physiology*; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000378:metabolism; D002648:Child; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D002149:Energy Intake; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage; D008019:Life Style; D008137:Longitudinal Studies; D008274:Magnesium / Q000008:administration & dosage / Q000378:metabolism; D008297:Male; D016226:Phosphorus, Dietary / Q000008:administration & dosage / Q000378:metabolism; D012044:Regression Analysis; D012737:Sex Factors; D014812:Vitamin K / Q000008:administration & dosage; D015032:Zinc / Q000008:administration & dosage
D002136:Calcium, Dietary; D004044:Dietary Proteins; D019266:Iron, Dietary; D016226:Phosphorus, Dietary; D014812:Vitamin K; D008274:Magnesium; D015032:Zinc