A Study of Factors Affecting Bone Mineral Density in Children : Anthropometric Measurements, Socioeconomic Factors, Family History, and Other Environmental Factors

ABSTRACT

This study was conducted to investigate the bone mineral density (BMD) and the anthropometric measurements, socioeconomic factors, family history of osteoporosis and other environmental factors affecting BMD in children. One hundred sixty children (80 males, 80 females) in second grade of elementary school in Seoul were recruited; the mean age was 7.7 +/- 0.47 years. Bone mineral density was measured in the lumbar spine (LS), femoral neck (FN), femoral trochanter (FT), and Ward's triangle (WT) by Dual Energy X-ray Absorptiometry (DEXA). Socioeconomic factors, family history of osteoporosis, and other environmental factors were assessed by questionnaire. Bone mineral densities of LS, FN, FT, and WT were 0.677, 0.637, 0.618, and 0.658 g/cm2. BMD of boys was higher than that of girls (LS 0.685 vs. 0.669, FN 0.660 vs. 0.614, FT 0.632 vs. 0.604, WT 0.678 vs. 0.639 g/cm2). Anthropometric measurements (height, weight, relative body weight, circumference of waist and hip) were positively correlated with BMD. With increasing family income, BMD of LS was significantly lowered, and negative correlation was observed between mother's age at birth of subject and the BMD of FN. And the BMD of children with a family history of osteoporosis was significantly lower. However BMDs were not different by educational level of parents, family pattern, delivery term, birth weight, and type of feeding. Further studies are needed to clarify the factors affecting BMD of children and earlier age, included infants and even prenatal life. If any association is revealed and persist until the attainment of peak bone mass, osteoporosis prevention programs are needed to be start very early in the life cycle.