[Study on the association between risk factors for osteoporosis and bone mineral density]

The relationship between bone mineral density (BMD) and risk factors for osteoporosis was investigated on 146 females (23-68 years old) in Enzan city, Yamanashi prefecture. BMD was measured by DEXA (Dual Energy X-ray Absorptiometry) method. Information regarding menstruation, health status, life-style, quantities of nutrient intake and frequencies of food intake were obtained by questionnaire. Fitness level was determined by exercise test and daily energy expenditure by calorie-counter. The results were as follows; 1) No relationship between physical activities or daily energy consumption and BMD was found. 2) No relationship between calcium intake or vitamin D intake and BMD was found, but a significant and positive correlation coefficient between intake frequency of milk products and BMD was observed. 3) Significant influences of age, BMI, presence of lumbago and food frequency score on BMD were indicated by multiple regression analysis. Food frequency score were defined as values weighted in each of three food category, obtained by factor analysis. 4) Significant influences of height decrement rate per year and number of years postmenopausal on BMD reduction rate per year were indicated by multiple regression analysis. These results suggest that these significant factors are useful in indications of risk for osteoporosis.