| Section1:Women’s bone mineral density during the process of ovarian failure[Background]From perimenopause, women’s level of estrogen decreases dramatically, due to the loss of ovarian function. The deficiency of estrogen, which attributes to the protection of bone mineral density (BMD), increases the risk of osteoporosis and fractures among women in this period of time.Some prospective studies from other countries have been conducted to evaluate the change of women’s BMD during the process of ovarian failure, such as the Study of Women’s Health Across the Nation (SWAN) and the Michigan Bone Health and Metabolism Study. These studies discovered that the rates and cumulative amounts of bone loss were greatest from1or2years before through2years after the finial menstrual period (FMP).The Chinese women have seriously different life style, dietary structure and exercise habits. At the meantime, several studies have confirmed that Asian women had more serious bone and muscle problems during the process of ovarian function loss. However, the studies focusing on Chinese women are limited and imperfect. There is only one cross-sectional study directed by Ouyang from Fudan University try to find out the relationship between women’s ovarian function and their BMD.In this study, the change of BMD during the process of ovarian function loss was investigated in a Chines population based prospective cohort study.[Objectives]To describe the change of women’s BMD at the whole body, the2nd to4th lumbar spine (lumbar spine2-4), femoral neck and Wards during the process of ovarian failure.[Methods]This is a prospective cohort study followed by Gynecological Endocrinology and Women’s Health Center in Peking Union Medical College Hospital (PUMCH) from July in2005to August in2013. Participants with FMP during the period of follow up were enrolled according to the eligibility criteria. Clinical characteristics and annual BMD measurement at the whole body, lumbar spine2-4, femoral neck and Wards were abstracted.Analyses were conducted using SAS version9.2. Firstly, Nonparametric, LOESS-based selection of functional form was used to generate BMD trajectories. Then piecewise liner regression was used to determine knots placement for the four BMD trajectories, and define every time intervals. After that, ANOVA for quantitative data in single-factor repeated-measurement design was used to compare annual BMD in each time intervals. Finally, annualized races and amounts of BMD loss during each time intervals of the trajectory were calculated.[Results]1. The participant enrolled in the srudyThe prospective cohort study followed by Gynecological Endocrinology and Women’s Health Center in PUMCH collect1100participants from July in2005to Auguest in2013.124participants were included in this study for analysis. The mean value of age at baseline was48.48±3.13years (ranged from41to55years), and the mean age of menopause was51.09±2.60years (ranged from44to58years).2. The change of BMD at the whole body during the process of ovarian function lossBy nonparametric, LOESS-based selection of functional form, the trajectory of BMD at the whole body from the5years before through the5years after the FMP was generated. By analyzing with piecewise liner regression, the knots placed at about the2nd year before (T=-1.9179) and the3rd year after (T=2.8395) the FMP, which suggested that the trend of BMD at the whole body had a significant change at these two knots.Results from the ANOVA for repeated-measurement design:during the period of5years before through2years before the FMP, there was no significant difference between annual BMD at the whole body (F=0.65, P=0.550); during the period of2years before through3years after the FMP, there was a significant difference between annual BMD at the whole body (F=147.26, P<0.001); and during the period of3years after through5years after the FMP, there was a significant difference between annual BMD at the whole body as well (F=9.77, P=0.001).During the period of2years before through3years after the FMP, annualized amounts of the whole body BMD loss was0.0134±0.0049g/cm2/yr and annualized rates was 1.21±0.46%/yr. During the period of3years after through5years after the FMP, annualized amounts and rates of the whole body BMD loss was0.0059±0.0102g/cm2/yr and0.56±0.95%/yr respectively.3. The change of BMD at lumbar spine2-4during the process of ovarian function lossBy nonparametric, LOESS-based selection of functional form, the trajectory of BMD at lumbar spine from the5years before through the4years after the FMP was generated. By analyzing with piecewise liner regression, the knots placed at about the2nd year before (T=-1.9361) and the3rd year after (T=2.9295) the FMP, which suggested that the trend of BMD at lumbar spine2-4had a significant change at these two knots.Results from the ANOVA for repeated-measurement design:during the period of5years before through2years before the FMP, there was no significant difference between annual BMD at lumbar spine2-4(F=0.20, P=0.880); during the period of2years before through3years after the FMP, there was a significant difference between annual BMD at lumbar spine2-4(F=55.36, P<0.001); and during the period of3years after through4years after the FMP, there was no significant difference between annual BMD at lumar spine2-4(F=3.78, P=0.068).During the period of2years before through3years after the FMP, annualized amounts of lumbar spine2-4BMD loss was0.0247±0.0133g/cm2/yr and annualized rates was2.19±1.26%/yr.4. The change of BMD at femoral neck during the process of ovarian function lossBy nonparametric, LOESS-based selection of functional form, the trajectory of BMD at femoral neck from the5years before through the4years after the FMP was generated. By analyzing with piecewise liner regression, the knots placed at about the2nd year before (T=-1.9907) and the3rd year after (T=3.0748) the FMP, which suggested that the trend of BMD at femoral neck had a significant change at these two knots.Results from the ANOVA for repeated-measurement design:during the period of5years before through2years before the FMP, there was no significant difference between annual BMD at femoral neck (F=1.08, P=0.353); during the period of2years before through3years after the FMP, there was a significant difference between annual BMD at femoral neck (F=39.32, P<0.001); and during the period of3years after through4years after the FMP, there was no significant difference between annual BMD at femoral neck (F=1.92,P=0.182).During the period of2years before through3years after the FMP, annualized amounts of femoral neck BMD loss was0.0119±0.0050g/cm2/yr and annualized rates was1.32±0.61%/yr.5. The change of BMD at Wards during the process of ovarian function lossBy nonparametric, LOESS-based selection of functional form, the trajectory of BMD atWards from the5years before through the4years after the FMP was generated. By analyzing with piecewise liner regression, the knots placed at about the2nd year before (T=-1.7927) and the3rd year after (T=3.1465) the FMP, which suggested that the trend of BMD at Wards had a significant change at these two knots.Results from the ANOVA for repeated-measurement design:during the period of5years before through2years before the FMP, there was no significant difference between annual BMD at Wards (F=2.68, P=0.059); during the period of2years before through3years after the FMP, there was a significant difference between annual BMD at Wards (F=50.68, P<0.001); and during the period of3years after through4years after the FMP, there was no significant difference between annual BMD at Wards (F=2.18, P=0.157).During the period of2years before through3years after the FMP, annualized amounts of Wards BMD loss was0.0171±0.0071g/cm2/yr and annualized rates was2.24±0.97%/yr.[Conclusions]1. Women’s BMD changed significantly during the process of ovarian failure.2. The BMD loss was greatest from2years before through3years after the FMP at whole body, lumbar spine2-4, femoral neck and Wards.3. The bone loss at whole body decelerated from the3years through5years after the FMP, but did not cease. Section2:Effects of walking on the preservation of bone mineral density in perimenopausal and postmenopausal women[Background]Several studies and the results from the section1of this study by evaluating the change of BMD of124participants with FMP during the process of ovarian function loss have confirmed that the risk of low BMD, osteoporosis and fracture increases among perimenopausal and postmenopausal women.The women with low BMD or osteoporosis have lots of physical and psychological symptoms, such as multiple and general ache, bone deformity, fractures, anxiety, depression, lack of self-confidence, etc. These problems will intensify individual, familial and governmental burden.Several studies have found that exercise can improve perimenopausal and postmenopausal women’s BMD. Meanwhile, walking exercise is one of the most acceptable exercises, due to its easy and convince.Many trials from other countries have confirmed that walking has significant and positive effects on women’s BMD. The studies have been carried out in South Korea, Japan, the United State and the United Kindom with the follow up time3to12months. These studies determined that walking exercise with medium intensity or above has positive effects on postmenopausal women’s BMD except radius. A key point is that above-mationed studies just included postmenopausal women, not perimenopausal women. However, the loss of women’s BMD starts from the2nd year before the FMP. Therefore, it’s very necessary to evaluate the effects of walking on the preservation of BMD in postmenopausal women as well perimenopausal women.Besides that, Chinese women have different life style from Westen women. The effects of walking and the acceptability of walking for Chinese women should be dicussed. However, these kinds of studies in China are limited and imperfect. The studies directed by Zhang Ming and Gao Honglian both have the problems of too less sample size and too short interventing time.This study focusing on Chinese perimenopausal and postmenopausal women, evaluates the effects of long time walking exercise (1-year) on preservating BMD [Objectives]To evaluate the effects of a1-year period walking intervention on the preservation of BMD at the whole body, lumbar spine2-4, femoral neck and Wards in perimenopausal and postmenopausal women.[Methods]This is a controlled trial. Participant of this section were enrolled according to the eligibility criteria from a prospective cohort study followed by Gynecological Endocrinology and Women’s Health Center in Peking Union Medical College Hospital (PUMCH). According to participants’ preference, intervention group and control group were recruited.The intervention group followed a1-year period of walking with a heart rate monitor and reported walking diaries. The participants in the control group were asked to keep their previous exercise habit. BMD at the whole body, lumbar spine2-4, femoral neck and Wards were measured at baseline and after the intervention.Analyses were conducted using SAS version9.2. Paired samples t-test was used to determine differences between baseline and after the intervention for BMD within groups. Changes from baseline in intervention group and control group were compared by two independent samples t-test.[Results]1. The completion of participants104participants were included in this study (intervention group, n=52; control group, n=52). After1-year intervention/follow up,46participants in intervention group completed the trial, percentage completion is88.46%; while50participants in control group completed the trial, percentage completion is96.15%.2. The comparation between the BMD at baseling and after intervention in the intervention group and the control groupIn the intervention group, there was no significant difference between the BMD at baseline and after intervention at the whole body (baseline:1.093±0.071g/cm2vs after intervention:1.094±0.073g/cm2, t=-0.832, P=0.410), lumbar spine2-4(baseline:1.165±0.141g/cm2vs after intervention:1.165±0.147g/cm2, t=-0.144, P=0.886) and femoral neck (baseline:0.884±0.099g/cm2vs after intervention:0.879±0.105g/cm2, t=1.662, P=0.104). Whine, the BMD of Wards decreased significantly (baseline: 0.746±0.123g/cm2vs after intervention:0.732±0.130g/cm2, t=3.870, P<0.001).In the control group, the BMD of whole body (baseline:1.093±0.063g/cm2vs after follow-up:1.080±0.066g/cm2, t=6.563, P<0.001), lumbar spine2-4(baseline:1.163±0.141g/cm2vs after follow-up:1.146±0.151g/cm2, t=2.869, P=0.006), femoral neck (baseline:0.898±0.083g/cm2vs after follow-up:0.879±0.086g/cm2, t=6.983, P<0.001) and Wards (baseline:0.746±0.083g/cm2vs after follow-up:0.725±0.087g/cm2, t=5.931, P<0.001) all decreased from baseline significantly.3. The comparation between the change of BMD from baseling to after intervention in the intervention group and the control groupThere were significant differences for the changes of the BMD from baseline of whole body (the BMD change in the intervention group:0.001±0.009g/cm2vs the change of BMD in the control group:-0.013±0.013g/cm2, t=5.883, P<0.001), lumbar spine2-4(the BMD change in the intervention group:0.001±0.037g/cm2vs the change of BMD in the control group:-0.017±0.041g/cm2, t=2.183, P=0.032) and femoral neck (the BMD change in the intervention group:-0.005±0.020g/cm2vs the change of BMD in the control group:-0.020±0.020g/cm2, t=3.667, P<0.001) between the intervention group and the control group, during the1-year period. The BMD of Wards decreased more seriously in the control group, but the difference is not significant (the BMD change in the intervention group:-0.014±0.024g/cm2vs the change of BMD in the control group:-0.021±0.025g/cm2, t=1.399, P=0.165).[Conclusions]1.1-year period of walking has significant and positive effects on decreasing the BMD loss at whole body, lumbar spine2-4and femoral neck in perimenopausal and postmenopausal women.2. The effects of1-year period of walking on preserving perimenopausal and postmenopausal women’s Wards BMD should be confirmed by further studies. |
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