Determinants of Bone Mass and Size in Term, Near-Term, and Preterm Children

Osteoporosis is a metabolic bone disease characterized by decreased bone mass and strength resulting in increased fracture risk. Peak bone mass is considered to be the major determinant of osteoporosis risk. Although peak bone mass is believed to be genetically determined, lifestyle factors such as diet and exercise may modify the risk of osteoporosis, especially implemented early in life. The goals of conducting the research studies presented in this dissertation were to identify those individuals who are at risk early in life, and to examine the influence of gestational age, prematurity related factors, physical activity, diet, and psychosocial factors on bone mass and size. Analyses were performed to determine whether bone differences exist among children born term, near-term and preterm and whether differences in bone loading (walking age and activity levels), calcium intake, and child rearing anxiety explain differences in bone measures. The results indicated that preterm and near-term boys have lower bone mass and size at various sites compared to term boys. Bone differences in boys were, in part, explained by lower physical activity measures in one study but not in the other. Reasons for this unconsistency [sic] ar [sic] discussed