Purpose: Obtaining high peak bone mass (PBM) and maintaining bone mass is important for the prevention of osteoporosis. This study aimed to examine the regional differences in bone mineral density and factors associat...Purpose: Obtaining high peak bone mass (PBM) and maintaining bone mass is important for the prevention of osteoporosis. This study aimed to examine the regional differences in bone mineral density and factors associated with its acquisition from exercise. Design: The study population included 75 women of 18 - 22 years of age in East Japan and 104 women of 18 - 27 years of age in West Japan. The speed of sound (SOS) of the calcaneus was measured, and the young adult mean (%YAM) was calculated from the SOS. The subjects’ medical history, family history of osteoporosis, and exercise habits were examined using a self-administered questionnaire. Results: There were a significantly greater number of subjects with low %YAM in West Japan. The exercise history and exercise time were significantly higher in West Japan, and the exercise intensity score tended to be higher in East Japan during junior high and high school. A multiple regression analysis by region revealed that the following factors had a significant positive association with the SOS: exercise intensity at elementary school and outdoor sports at junior high school in East Japan;and exercise time at elementary school, muscle mass, and outdoor sports at junior high school in West Japan. On the other hand, exercise time in junior high school in West Japan showed a negative association with the SOS. Conclusions: Regional differences in bone mineral density existed, suggesting a trend toward lower bone mineral density in West Japan. Exercise history and time tended to be higher in West Japan, and exercise intensity scores tended to be higher in East Japan, suggesting that exercise intensity may be more important than exercise time for obtaining bone mineral density.展开更多
Although cortisol is believed to increase the osteoclast activity and accentuate bone resorption, few studies are available on cortisol and bone density. This study uses salivary cortisol to investigate the relationsh...Although cortisol is believed to increase the osteoclast activity and accentuate bone resorption, few studies are available on cortisol and bone density. This study uses salivary cortisol to investigate the relationship thereof with bone density. Furthermore, we investigated whether the salivary Ca concentration could be an effective biomarker in bone evaluations using salivary cortisol. This study targeted 188 healthy female college students (18 - 25 years old). Calcaneus bone density (Speed of Sound: SOS) was measured using an ultrasonic bone density measurement device. Food intake was calculated via a food intake frequency survey. The saliva of subjects was collected in order to measure the cortisol concentration using an enzyme immunoassay, while the salivary Ca concentration was measured using an atomic absorption spectrophotometer. The relationship between salivary cortisol and SOS was not significant, with a correlation coefficient of -0.13, indicating a negative correlation and leading to the observation that those with lower salivary cortisol levels tended to have higher SOS. The relationship between salivary cortisol and salivary Ca concentration was not significant, with a correlation coefficient of +0.15, indicating a positive correlation and leading to the observation that those with higher salivary cortisol concentrations tended to have higher salivary Ca concentrations. No significant correlation was observed in the relationship between salivary Ca concentration and SOS. Because the cortisol in saliva responds more sensitively to acute stress than to chronic stress, this may not have had obvious significance. Furthermore, the salivary Ca concentration indicated large fluctuations, depending on the daily external conditions, particularly in terms of food;therefore, it is believed that the presence or absence of dietary intake before the survey affected the results. The above results suggest that bone density may decrease, while salivary Ca concentration may increase when salivary cortisol concentration increases due to stress.展开更多
文摘Purpose: Obtaining high peak bone mass (PBM) and maintaining bone mass is important for the prevention of osteoporosis. This study aimed to examine the regional differences in bone mineral density and factors associated with its acquisition from exercise. Design: The study population included 75 women of 18 - 22 years of age in East Japan and 104 women of 18 - 27 years of age in West Japan. The speed of sound (SOS) of the calcaneus was measured, and the young adult mean (%YAM) was calculated from the SOS. The subjects’ medical history, family history of osteoporosis, and exercise habits were examined using a self-administered questionnaire. Results: There were a significantly greater number of subjects with low %YAM in West Japan. The exercise history and exercise time were significantly higher in West Japan, and the exercise intensity score tended to be higher in East Japan during junior high and high school. A multiple regression analysis by region revealed that the following factors had a significant positive association with the SOS: exercise intensity at elementary school and outdoor sports at junior high school in East Japan;and exercise time at elementary school, muscle mass, and outdoor sports at junior high school in West Japan. On the other hand, exercise time in junior high school in West Japan showed a negative association with the SOS. Conclusions: Regional differences in bone mineral density existed, suggesting a trend toward lower bone mineral density in West Japan. Exercise history and time tended to be higher in West Japan, and exercise intensity scores tended to be higher in East Japan, suggesting that exercise intensity may be more important than exercise time for obtaining bone mineral density.
文摘Although cortisol is believed to increase the osteoclast activity and accentuate bone resorption, few studies are available on cortisol and bone density. This study uses salivary cortisol to investigate the relationship thereof with bone density. Furthermore, we investigated whether the salivary Ca concentration could be an effective biomarker in bone evaluations using salivary cortisol. This study targeted 188 healthy female college students (18 - 25 years old). Calcaneus bone density (Speed of Sound: SOS) was measured using an ultrasonic bone density measurement device. Food intake was calculated via a food intake frequency survey. The saliva of subjects was collected in order to measure the cortisol concentration using an enzyme immunoassay, while the salivary Ca concentration was measured using an atomic absorption spectrophotometer. The relationship between salivary cortisol and SOS was not significant, with a correlation coefficient of -0.13, indicating a negative correlation and leading to the observation that those with lower salivary cortisol levels tended to have higher SOS. The relationship between salivary cortisol and salivary Ca concentration was not significant, with a correlation coefficient of +0.15, indicating a positive correlation and leading to the observation that those with higher salivary cortisol concentrations tended to have higher salivary Ca concentrations. No significant correlation was observed in the relationship between salivary Ca concentration and SOS. Because the cortisol in saliva responds more sensitively to acute stress than to chronic stress, this may not have had obvious significance. Furthermore, the salivary Ca concentration indicated large fluctuations, depending on the daily external conditions, particularly in terms of food;therefore, it is believed that the presence or absence of dietary intake before the survey affected the results. The above results suggest that bone density may decrease, while salivary Ca concentration may increase when salivary cortisol concentration increases due to stress.
