We investigated the relationships of the bone mineral density with the nutritional intake, physical activity habit, and other life-style factors among elderly residents of Hisayama for application to preventive medicine.
The number of male smokers was significantly higher than no-smokers and former smokers. There was no significant difference among each female smoking group. There was no significant difference among each male physical activity group, but the sedentary group had significantly lower activity (4-7days/week) among the females. The sodium intake by the males was significantly different among the H-group and L-group, but there was no significant difference in the intake of other nutrients among the three groups. The energy intake by the females was significantly different among the H-group and L-group. There was no significant difference among the in three male groups in the percentages of the recommended daily allowance (RDA) for nutrition. The percentage RDA values for energy and protein were significantly different among the female H-group and L-group. A factor analysis gave a significantly lower second factor score in the L-group than in the M-group and H-group of both males and females. The second factor was interpreted as a "bread-style diet" and "rice style diet".
These results suggest that a sexual difference exists in the factors which affect the bone mineral density, especially the nutritional factor. It is therefore necessary to recommend reducing the sodium (NaCl) intake by men to prevent a fall in the bone mineral density, while the women need to ensure sufficient protein and calcium to meet the RDA values. It is also necessary to counsel the elderly women in a food consumption pattern that provides an easily acceptable intake of calcium.