Effects of Milk Consumption on Calcaneal Quantitative Ultrasound and Bone Turnover Markers of Women Living in Asan

아산시 거주 여성에서 우유섭취가 골초음파 상태와 골대사지표에 미치는 영향

The objective of this study is to determine the effectiveness of 16-month milk consumption as a part of the health promotion community program for women in Asan. Subjects included 313 women belonging to the milk group (mean age = 69.1, range $47{\sim}89 y$) and 66 women to the control (mean age=43.6, range $20{\sim}69 y$) group. For those in the milk group, one cup (200 ml) of partially lactose-digested low-fat milk was provided everyday for 16 months. Each subject was interviewed to assess calcium intake by a 24-h recall after fasting blood was obtained for analyzing bone turnover markers, and calcaneus broadband ultrasound attenuation (BUA) was measured by quantitative ultrasound (QUS) on the left heel before and after the milk supplementation. After 16 months, the calcium intake levels changed from 55% of recommended dietary allowance (RDA) to 85% RDA in the milk group and from 73% RDA to 84% RDA in the control group. BUA were reduced from $67.9{\pm}8.1$ to $64.7{\pm}17.5$ dB/MHz for milk and from $90.4{\pm}13.0$ to $87.2{\pm}15.2$ dB/MHz for control groups. Paired t-test showed the changes of BUA for both groups (-3.24 and -3.15 dB/MHz for milk and control groups, respectively) were significant, but the two groups did not show any differences in absolute changes. When post-BUA was analyzed after age, initial BUA and menopausal status were controlled as covariates in ANCOVA model, the milk group showed significantly (p < 0.05) smaller changes than the control group (-3.50 vs -6.71 dB/MHz, respectively). According to a multiple regression analysis, milk consumption and initial BUA showed significant interaction meaning that those with lower initial BUA showed higher milk effects. We conclude that one-cup a day milk consumption for 16 month can prevent further bone loss and significantly improve calcium intake.