Some Factors Affecting Bone Mineral Density of Korean Rural Women

농촌 성인 여성들의 골밀도에 영향을 미치는 요인 분석 연구

The factors affecting bone mineral density (BMD) of 103 rural women aged 30 to 76 years were investigated. Data for food and nutrient intake was obtained by 24-hour recall method. BMD of lumbar spine(L1-L4), femoral neck, ward's triangle and trochanter was measured by XR-series x-ray bone densitometer. Serum was collected and analyzed for total Ca, P and ionized Ca (Ca++)content. Relationship between the factors and BMDs was analyzed by Pearson's correlation coefficient(r) and multiple regression analysis. The results are summarized as follows. 50% of the subjects under 50 years of age($\leq$49 yr group) and 86.4% of the subjects from 50 up($\geq$50yr group) were classified as osteopenia or osteoporosis. Mean body weight, height and BMI were 153.1cm, 59.1kg and 25.0kg/$m^2$ in $\leq$49 yr group and 151.9cm, 55.9kg, and 24.2kg/$m^2$ in $\geq$50 yr group. BMDs of lumbar spines and femurs ranged from 0.84 to 1.05g/$m^2$ and from 0.67 to 1.16g/$m^2$ in $\leq$49 yr group, and ranged from 0.67 to 0.85kg/$m^2$ and from 0.68 to 0.44g/$m^2$ in $\geq$50 yr group, respectively. On the whole, the BMDs were reduced to 83.8 to 94.2% of peck bone mass in $\leq$49 yr group and 55.2 to 78.9% of those in $\geq$50 yr group. Mean daily intake of Ca was much less than the Korean RDA, \67.2% in $\leq$49 yr group and 62.3% in $\geq$50 yr group. The average concentration of total Ca, P and Ca++ in serum were within normal range in both age group. Both age and height were significantly related with BMD in both age group but the relationship tended to be stronger in $\geq$50 yr group than in $\leq$49 yr group. Body weight was also a potent determinant of BMD only in 50 yr group. In $\leq$49 yr group, total food intake was positively related with BMDs of ward's triangle, L1 and L2 and intake of cereals and grain products, sugars and sweets, milk and dairy products was positively related with BMDs measured in this study. On the contrary, intake of eggs, oil and fats were positively related with a few BMDs in 50 yr group. The BMDs were positively affected by intake of energy, protein, carbohydrate, Ca, P and Fe in $\leq$49 yr group and those of protein, fat Ca, P, vitamin B1, vitamin B2 and vitamin C in $\geq$50 yr group. It was noteworthy that serum Ca++ concentration was positively related with BMDs of lumbar spine in boty age groups. According to multiple regression analysis, the four factors, age, body weight, height and BMI additionally accounted for 21% of the variance in BMD of trochanter in $\leq$49 yr group and only two factors, age and C a intake accounted for 38% of that of femoral neck in $\geq$50 yr group. Further investigation is necessary to make sure of the relations between BMD and serum Ca++ level.