[Relation between calcaneal bone mass and lifestyles in young adult women. Influence of experience of delivery and months post delivery].
The aim of this study was to clarify the cross-sectional relation between calcaneal bone mass and lifestyles in healthy pre-menopausal young adult women classified by the experience of pregnancy and the months after delivery. The 457 healthy Japanese women aged 20-39 years living in an urban community underwent a health check up for osteoporosis. Calcaneal bone was measured by ultrasound using the Lunar Achilles, and stiffness was used as an index of bone mass. The information on pregnancy, delivery and lactation, and lifestyles including past and current exercise and frequency of food consumption were collected by a questionnaire. In addition, two-day dietary records were obtained to assess the nutrient intake, and seven-day walking records as an index of physical activities. These subjects were divided into 3 groups according to the experience of pregnancy, and the time after delivery (subgroups of no experience of pregnancy, 12-35 months post-delivery and 36 months or more post-delivery), and the relation between stiffness index and lifestyle factors was examined in the 3 groups. 1) Stiffness correlated significantly with experience of pregnancy, age at menarche, current exercise and frequency of intake of dairy products. 2) In the group without experience of pregnancy, stiffness in women with current exercise habit was significantly higher than women without the habit. Those with past exercise habit, current milk consumption and current calcium intake showed relatively greater stiffness. 3) In the 12-35 months post-delivery group, there was no relation of past and current physical activity to stiffness. For women whose frequency of milk consumption or daily calcium intake were high, the stiffness was significantly greater. In addition, past milk consumption and current frequency of dairy products consumption tended to show higher stiffness. 4) In 36 months or more post-delivery group, women with current exercise habit exhibited significantly higher stiffness than women without the habit. Low calcium intake tended to show low stiffness. These results indicated that the effects of lifestyle on calcaneal bone mass were different depending on the experience of pregnancy and the months after delivery in pre-menopausal young adult women.
Koitaya
N
N
Division of Human Development, Graduate School of Human Life Science, Japan Women's University.
Ishikawa
K
K
Oota
T
T
Yoshimoto
K
K
Tanaka
S
S
Ezawa
I
I
D000328:Adult; D015519:Bone Density; D002111:Calcaneus / Q000502:physiology; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008019:Life Style; D049590:Postpartum Period; D011247:Pregnancy; D017697:Premenopause