A Comparative Study of Bone Mineral Density and Urinary Bone Metabolic Makers according to the Nutrients Intake Levels in Postmenopausal Women

ABSTRACT

To elucidate the relationship among the levels of nutrients intake, bone mineral density (BMD) and the urinary biochemical markers of bone metabolism, this survey is conducted with 225 postmenopausal women over 50 years of age. The urinary biochemical markers including deoxypyridinoline (DPD) and Ca excretion were measured. Bone mineral densities of lumbar spine (L2-L4), femoral neck, ward's triangle and trochanter were measured with dual-energy X-ray absorptiometry and the nutrient intake data obtained by 24 hr recall method. Mean age of all subjects was 64.8 years old, and the BMDs of the subjects were 0.86 g/cm2 (lumbar spine), 0.60 g/cm2 (femoral neck), 0.49 g/cm2 (trochanter), and 0.41 g/cm2 (ward's triangle). The results were compared among 3 groups with different nutrient intake levels classified by the percentage of Dietary Reference Intakes (DRIs) for Koreans as follows low or = 125% DRIs. Bone mineral density of adequate protein intake group was significantly higher than those of low and high protein intake groups (p < 0.05). Urinary DPD excretion was lowest in protein and calcium adequate intake groups (p < 0.05, p < 0.05), respectively. In relation to urinary Ca excretion, it is revealed to be considerably lower in the groups taking protein and vitamin C adequate intake (p < 0.05, p < 0.05). The percent DRI of protein and calcium were positively correlated with the BMD of the femoral neck after adjusted age (p < 0.05, p < 0.05). These results showed that there are probably some relationships between nutrient intake levels and urinary biochemical markers. For postmenopausal women with adequate nutrition expecially protein, calcium and vitamin C, has an important role to postpone bone resorption and to prevent the decrease of bone density.