Reproductive Factors Affecting the Bone Mineral Density in Postmenopausal Women

Is first pregnancy age associated with hypertension in the Chinese rural women population?

Introduction

The purpose of this study was to investigate the relationship between first pregnancy age and hypertension later in the life of women from Chinese rural areas.

Methods

In total, 13,493 women were enrolled in the Henan Rural Cohort study. Logistic regression and linear regression were used to evaluate the association between first pregnancy age and hypertension and blood pressure indicators [including systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP)]. The restricted cubic spline was used to examine the dose-response relationship between the first pregnancy age and hypertension or blood pressure indicators.

Results

After adjusting for potential confounders, each 1-year increase in first pregnancy age was associated with a 0.221 mmHg increase in SBP values, a 0.153 mmHg increase in DBP values, and a 0.176 mmHg decrease in MAP values (all P < 0.05). The β of SBP, DBP, and MAP showed a trend of first increasing and then decreasing with increasing first pregnancy age and there was no statistical significance after first pregnancy age beyond 33 years on SBP, DBP, and MAP, respectively. A 1-year increment in first pregnancy age was associated with a 2.9% [OR (95% CI): 1.029 (1.010, 1.048)] higher odds of prevalent hypertension. The odds of hypertension increased sharply and then eventually leveled off with an increment of first pregnancy age after adjusting for potential confounders.

Conclusion

First pregnancy age might increase the risk of hypertension later in life and might be an independent risk factor for hypertension in women.

Adolescent Sport Participation and Age at Menarche in Relation to Midlife Body Composition, Bone Mineral Density, Fitness, and Physical Activity

This study aimed to investigate the associations of competitive sport participation in adolescence and age at menarche (AAM) with body composition, femoral neck bone mineral density (BMD), physical performance, and physical activity (PA) in middle-aged women. 1098 women aged 47–55 years formed the sample of this retrospective study. Participants self-reported their PA level at age 13–16 years and AAM. The protocol also included dual-energy X-ray absorptiometry, physical performance tests, and accelerometer-measured PA. Participants were divided into three groups according to their PA level at the age of 13–16 (no exercise, regular PA, and competitive sport) and according to their AAM (≤12, 13, and ≥14 years). After adjusting for potential confounding factors, participation in competitive sport at age 13–16 was associated with higher midlife lean mass and BMD, and better physical performance compared to groups with no exercise or regular PA. Individuals with AAM ≥ 14 years had lower midlife BMI and fat mass than participants in the other AAM groups and pre- and perimenopausal women with AAM ≥ 14 years had lower BMD than those with AAM ≤ 12. The findings indicate that participation in competitive sport in adolescence is associated with healthier body composition, higher BMD, and better physical performance in midlife, but BMD might be impaired if menarche occurs late.

Effect of Childbirth Age on Bone Mineral Density in Postmenopausal Women

BACKGROUND

In postmenopausal women, there is rapid bone loss due to estrogen depletion. In women, reproductive factors such as age at menarche, breastfeeding, and parity are considered risk factors of osteoporosis. Many reports suggest that obesity is associated with a reduced risk of osteoporosis. This nationwide, population-based study aims to identify the association between maternal age and osteoporosis risk in postmenopausal women of different obesity classifications.

METHODS

We assessed data from the Korean National Health and Nutrition Examination Survey 2010-2012. The study included 1,328 postmenopausal women, after excluding women with missing data for reproductive history among 4,546 postmenopausal women in the survey. Multivariate regression was used to identify the association between childbirth age and postmenopausal bone mineral density after adjustments for confounding factors.

RESULTS

The prevalence of postmenopausal osteoporosis was 35.24% (n = 468). After dividing the subjects into obese and non-obese groups based on body mass index (BMI) and waist circumference, there were significant differences between non-osteoporosis and osteoporosis groups with regard to age at first childbirth, age at last childbirth, and parity in the BMI-based general obesity group. The prevalence of osteoporosis was highest in women older than 35 years old at last childbirth. The prevalence of osteoporosis was also greater in women with parity ≥ 4 compared to those with lower parity levels.

CONCLUSION

Postmenopausal women of older age at last childbirth and higher parity were at increased risk of osteoporosis in the BMI-based non-general obesity group.

Effect of parity on bone mineral density: A systematic review and meta-analysis

INTRODUCTION

Parity has been suggested as a possible factor affecting bone health in women. However, study results on its association with bone mineral density are conflicting.

METHODS

PubMed, EMBASE, the Cochrane Library, and Korean online databases were searched using the terms "parity" and "bone mineral density", in May 2016. Two independent reviewers extracted the mean and standard deviation of bone mineral density measurements of the femoral neck, spine, and total hip in nulliparous and parous healthy women.

RESULTS

Among the initial 10,146 studies, 10 articles comprising 24,771 women met the inclusion criteria. The overall effect of parity on bone mineral density was positive (mean difference=5.97mg/cm²; 95% CI 2.37 to 9.57; P=0.001). The effect appears site-specific as parity was not significantly associated with the bone mineral density of the femoral neck (P=0.09) and lumbar spine (P=0.17), but parous women had significantly higher bone mineral density of the total hip compared to nulliparous women (mean difference=5.98mg/cm²; 95% CI 1.72 to 10.24; P=0.006). No obvious heterogeneity existed among the included studies (femoral neck I²=0%; spine I²=31%; total hip I²=0%).

CONCLUSION

Parity has a positive effect on bone in healthy, community-dwelling women and its effect appears site-specific.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

During pregnancy and lactation, female physiology adapts to meet the added nutritional demands of fetuses and neonates. An average full-term fetus contains ∼30 g calcium, 20 g phosphorus, and 0.8 g magnesium. About 80% of mineral is accreted during the third trimester; calcium transfers at 300-350 mg/day during the final 6 wk. The neonate requires 200 mg calcium daily from milk during the first 6 mo, and 120 mg calcium from milk during the second 6 mo (additional calcium comes from solid foods). Calcium transfers can be more than double and triple these values, respectively, in women who nurse twins and triplets. About 25% of dietary calcium is normally absorbed in healthy adults. Average maternal calcium intakes in American and Canadian women are insufficient to meet the fetal and neonatal calcium requirements if normal efficiency of intestinal calcium absorption is relied upon. However, several adaptations are invoked to meet the fetal and neonatal demands for mineral without requiring increased intakes by the mother. During pregnancy the efficiency of intestinal calcium absorption doubles, whereas during lactation the maternal skeleton is resorbed to provide calcium for milk. This review addresses our current knowledge regarding maternal adaptations in mineral and skeletal homeostasis that occur during pregnancy, lactation, and post-weaning recovery. Also considered are the impacts that these adaptations have on biochemical and hormonal parameters of mineral homeostasis, the consequences for long-term skeletal health, and the presentation and management of disorders of mineral and bone metabolism.

Effect of multiparity on bone mineral density, evaluated with bone turnover markers

OBJECTIVE

Our aim was to investigate the effect of parity on osteoporosis by evaluating bone mineral density, markers of bone turn-over and other factors that are effective in osteoporosis in multiparous (five deliveries or more) and nulliparous women in the post-menopausal period.

METHODS

A total of 91 multiparous (five deliveries or more) and 31 nulliparous postmenopausal women were included in this study. All patients were interviewed on sociodemographic characteristics, gynecologic history, personal habits, levels of physical activity, and life-long intake of calcium. Bone mineral density was measured at lumbar (L1-4) and femoral neck regions with Dexa.

RESULTS

The mean age of multiparous women was 58.79±7.85 years, and the mean age of nulliparous women was 55.84±7.51. The femoral BMD was 0.94±0.16 and lumbar BMD 1.01±0.16 in multiparous women, femoral BMD was 0.99±0.16 and lumbar BMD 1.07±0.14 in nulliparous women. There were no statistical differences between the femoral and lumbar T scores and BMD values of the two groups. Lumbar T scores and lumbar BMD showed a decrease with increasing total duration of breast-feeding in multiparous women. The independent risk factors for osteoporosis in the regression analysis of multiparous women were found to be the duration of menopause and body weight of 65kg and less.

CONCLUSION

There is no difference between the bone mineral densities of multiparous and nulliparous women. Females with lower body-weight and longer duration of menopause should be followed-up more carefully for development of osteoporosis.

Effect of reproductive history, lactation, first pregnancy age and dietary habits on bone mineral density in natural postmenopausal women

AIM

The aim of this study was to investigate the possible risk factors related with osteoporosis in women with spontaneous menopause.

METHODS

Five hundred and one postmenopausal women were divided into three groups as normal, osteopenic and osteoporotic according to their bone mineral density (BMD). By face-to-face interview, parity, age at menarche, age at menopause, duration of fertility, duration of menopause, first pregnancy age, total lactation period, exercise, smoking were assessed. Women with menopause age before 40 years, surgical menopause, who had any anti-osteoporosis treatment, hormone replacement therapy at the time of BMD measurement and corticosteroid use longer than 6 months were excluded from the study.

RESULTS

Among 501 postmenopausal women, 107 women were classified as normal, 170 as osteopenic and 224 as osteoporotic. Among demographic features of patients, there was statistically significant difference between the groups in age, BMI and parity (p < 0.001, p < 0.0001 and p = 0.002, respectively). There were statistically significant differences between the groups in case of age at menopause, duration of fertility and duration of menopause (p = 0.013, p = 0.013 and p < 0.0001, respectively). In the multivariate logistic regression analysis, BMI over 32 and fertility duration over 33 years had a statistically significant protective effect against osteoporosis (OR 0.42, CI 95 % 0.27-0.66; OR 0.36, CI 95 % 0.24-0.56, respectively), but age was positively correlated with osteoporosis (OR 1.13, CI 95 % 1.01-1.17) CONCLUSIONS: Duration of fertility (years of menstruation) longer than 33 years and body mass index higher than 32 seem to protect against postmenopausal osteoporosis. Age is also an independent risk factor for postmenopausal osteoporosis.

[Effect of multiparity on bone mineral density, evaluated with bone turnover markers]

OBJECTIVE

Our aim was to investigate the effect of parity on osteoporosis by evaluating bone mineral density, markers of bone turn-over and other factors that are effective in osteoporosis in multiparous (5 deliveries or more) and nulliparous women in the post-menopausal period.

METHODS

A total of 91 multiparous (5 deliveries or more) and 31 nulliparous postmenopausal women were included in this study. All patients were interviewed on sociodemographic characteristics, gynecologic history, personal habits, levels of physical activity, and life-long intake of calcium. Bone mineral density was measured at lumbar (L1-4) and femoral neck regions with Dexa.

RESULTS

The mean age of multiparous women was 58.79±7.85 years, and the mean age of nulliparous women was 55,84±7,51. The femoral BMD was 0,94±0,16 and lumbar BMD 1,01±0,16 in multiparous women, femoral BMD was 0,99±0,16 and lumbar BMD 1,07±0,14 in nulliparous women. There were no statistical differences between the femoral and lumbar T scores and BMD values of the two groups. Lumbar T scores and lumbar BMD showed a decrease with increasing total duration of breast-feeding in multiparous women. The independent risk factors for osteoporosis in the regression analysis of multiparous women were found to be the duration of menopause and body weight of 65kg and less.

CONCLUSION

There is no difference between the bone mineral densities of multiparous and nulliparous women. Females with lower body-weight and longer duration of menopause should be followed-up more carefully for development of osteoporosis.

Associations of Bone Mineral Density with Lean Mass, Fat Mass, and Dietary Patterns in Postmenopausal Chinese Women: A 2-Year Prospective Study

Objective

To assess factors associated with bone mineral density (BMD) in postmenopausal women in a longitudinal study, and to examine the relative contribution of lean mass, fat mass, dietary patterns, and years since menopause to BMD.

Methods

Two hundred and eighty-two postmenopausal women were randomly selected from Hongqi Community Health Center, in Harbin City, China. All participants were followed up from 2009 to 2011. Dietary data were collected using a Food Frequency Questionnaire. BMD of the left hip, the lumbar spine, and the total body, and the body composition were measured by dual-energy X-ray absorptiometry at baseline and follow-up.

Results

Lean mass and fat mass were positively associated with BMD of the spine, hip, and the total body at both baseline and follow-up. The association between fat mass and BMD at the spine at baseline (P = 0.210) and at the spine (P = 0.116) and hip (P = 0.073) in the second year was not statistically significant when height was adjusted. Six dietary patterns were identified but only cereal grains-fruits pattern (P = 0.001 in the spine, P = 0.037 in hip) and milk-root vegetables pattern (P = 0.010 in hip) were associated with BMD of the spine and hip. The linear mixed model of follow-up data showed that lean mass, years since menopause, and age of menophania were the significant determinants of BMD of all sites. Moreover, lean mass was the best determinant of BMD (VIP = 1.936).

Conclusion

Lean mass, years since menopause, age of menophania and dietary patterns are the important determinants of BMD of the spine, hip, and the total body. Lean mass is the best determinant of BMD.

O efeito da amamentação na massa óssea de mulheres na pós-menopausa: revisão sistemática de estudos observacionais

Objetivos:avaliar o efeito da amamentação na massa óssea de mulheres na pós-menopausa.Métodos:trata-se de revisão sistemática de estudos observacionais. A pesquisa da literatura foi realizada nas bases de dados bibliográficos Lilacs, Medline e Scopus, em junho de 2015, sem restrição quanto ao ano de publicação. Para ser incluído nesta revisão, o artigo deveria avaliar o histórico de amamentação e a massa óssea na pós-menopausa, sendo suas referências checadas para busca de novos estudos. Dois revisores, de forma independente, realizaram a extração de dados e a avaliação da suscetibilidade a vieses dos estudos.Resultados:foram selecionados 34 estudos, dos quais seis (26,5%) mostraram que a prática de amamentação aumentou significativamente a massa óssea e 15 (44%) encontraram o inverso. Constatou-se grande diversidade entre os estudos quanto à população de estudo, mensuração da exposição e sítios de avaliação da massa óssea, dificultando a comparabilidade entre os resultados.Conclusões:a marcante heterogeneidade dos estudos torna inconclusiva a direção da associação entre a amamentação e a massa óssea em mulheres na pós-menopausa, sendo necessários estudos com maior rigor metodológico para avaliar esse problema de grande relevância para as áreas clínica e de saúde pública.

Interpregnancy interval as a risk factor for postmenopausal osteoporosis

OBJECTIVE

Bone mass loss associated with pregnancy and lactation is usually regained in the postpartum period. However, it is not known whether the bone loss is completely recovered in women with a shortened interpregnancy interval (IPI). The aim of this study was to analyze the effect of IPI and gynecological history on postmenopausal osteoporosis.

STUDY DESIGN

The study was conducted among 537 postmenopausal women who were divided into two groups in accordance with the osteoporosis status. Prior to bone densitometry, the patients were questioned about reproductive history. Dual-energy X-ray absorptiometry was used to measure lumbar spinal, femur neck and total femoral bone mineral density.

MAIN OUTCOME MEASURE

Association between IPI and postmenopausal osteoporosis was analyzed.

RESULTS

The comparison of both groups according to the total duration of breastfeeding did not reveal a considerable variation (p=0.288). In the osteoporosis group the age and duration of menopause were found to be significantly higher (p<0.001) whereas the age of first pregnancy and IPI were notably lower in comparison to the controls group (p<0.001). Multivariate logistic regression analyses revealed that women who have 0-12 months interpregnancy interval have the highest risk for osteoporosis (OR: 4.306; 95% CI, 1.684-11.01). This analysis confirmed that the occurrence of first pregnancy under 27 years of age conveyed a higher risk for osteoporosis, as well.

CONCLUSIONS

Shortened IPI may have a detrimental effect on bone mineral density in postmenopausal age.

Influence of number of deliveries and total breast-feeding time on bone mineral density in premenopausal and young postmenopausal women

OBJECTIVES

Pregnancy and lactation have been associated with decline in bone mineral density (BMD). It is not clear if there is a full recovery of BMD to baseline. This study sought to determine if pregnancy or breast-feeding or both have a cumulative effect on BMD in premenopausal and early postmenopausal women.

STUDY DESIGN

We performed single-center cohort analysis. Five hundred women aged 35-55 years underwent routine BMD screening from February to July 2011 at a tertiary medical center. Patients were questioned about number of total full-term deliveries and duration of breast-feeding and completed a background questionnaire on menarche and menopause, smoking, dairy product consumption, and weekly physical exercise. Weight and height were measured. Dual-energy X-ray absorptiometry was used to measure spinal, dual femoral neck, and total hip BMD.

MAIN OUTCOME MEASURES

Associations between background characteristics and BMD values were analyzed.

RESULTS

Sixty percent of the women were premenopausal. Mean number of deliveries was 2.5 and mean duration of breast-feeding was 9.12 months. On univariate analysis, BMD values were negatively correlated with patient age (p=0.006) and number of births (p=0.013), and positively correlated with body mass index (p<0.001). On multiple (adjusted) logistic regression analysis, prolonged breast-feeding duration, but not number of deliveries, was significantly correlated to a low BMD (p=0.008). An effect was noted only in postmenopausal women. The spine was the most common site of BMD decrease.

CONCLUSIONS

Prolonged breast-feeding may have a deleterious long-term effect on BMD and may contribute to increased risk of osteoporosis later in life.

The impact of serum FSH and estradiol on postmenopausal osteoporosis related to time since menopause

AIM

To determine the impact on osteopenia/osteoporosis of serum follicle-stimulating hormone (FSH), estradiol levels and time since menopause in a group of Turkish postmenopausal women.

METHODS

Four hundred and thirty-three healthy postmenopausal women seen at the Marmara University Menopause Outpatient Clinic were enrolled for this prospective cohort study. The women were allocated to one of three groups according to the bone mineral density (BMD) of the lumbar vertebrae and total hip, as measured by dual energy X-ray absorptiometry (DEXA). Serum FSH, estradiol levels, age and time since menopause were compared between the groups.

RESULTS

The mean serum FSH, LH, estradiol and testosterone levels for women with normal, osteopenic and osteoporotic BMD at lumbar vertrebra L1-L4 and total hip were comparable. Time since menopause had a stronger predictive value for low BMD (osteopenia or osteoporosis) in the lumbar and hip areas than did serum FSH or estradiol levels.

CONCLUSIONS

Our study showed that neither FSH nor E2 has a strong impact on postmenopausal BMD. However it appears that time since menopause has a weak non-significant association with postmenopausal osteopenia and osteoporosis.

Bone fractures and incident epithelial ovarian cancer in a prospective cohort study

OBJECTIVE

Osteoporosis and osteoporotic fractures are hypothesized to reflect circulating hormone levels in older women and have been inversely associated with breast and endometrial cancers. However, associations between fractures and ovarian cancer, another hormonal cancer, have not been examined. Therefore, we conducted a prospective study among women in the Breast Cancer Detection Demonstration Project Follow-up Study.

METHODS

Fractures after age 45 were assessed using two questionnaires from 1987 to 1995. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards models, adjusting for potential confounders. Fracture location was used to further evaluate the fractures most likely to be osteoporotic.

RESULTS

Among 36,115 women with up to 11 years of follow-up (average follow-up was 8.3 years), there were 151 cases of incident ovarian cancer. Fractures were reported by 19% (n = 6,919) of women. Ovarian cancer risk was not associated with any (RR = 1.13, 95% CI 0.74-1.71) or likely osteoporotic (RR = 1.05, 95% CI 0.65-1.69) fractures. Among never users of postmenopausal hormones, the association between any fracture and ovarian cancer (RR = 1.21, 95% CI 0.55-2.65, n = 50 cases) also was statistically nonsignificant.

CONCLUSIONS

Data from this large, prospective study do not support an association between fractures and ovarian cancer risk.

Is osteoporosis in postmenopausal female patients related to previous pregnancies and/or miscarriages?

OBJECTIVE

To investigate if osteopenia and osteoporosis in postmenopausal female patients are related to previous pregnancies and/or miscarriages.

PATIENTS AND METHODS

We studied 81 postmenopausal female patients, 40 with osteopenia or osteoporosis and 41 without osteopenia or osteoporosis, carefully matched for age (control group). In the two groups, the presence or not of osteopenia, osteoporosis, or both, were analyzed and compared with the number of childbirths and/or miscarriages.

RESULTS

Overall, no statistical difference was found among the 40 patients with one, two, three or more than three childbirths and osteopenia or osteoporosis compared with the control group (p=0.5363, p=0.5782, p=0.0763, p=0.1931, respectively). Similarly, no differences were found between the osteopenia/osteoporosis group and the control group in relation to previous one, two, three or more than three miscarriages. When both childbirths and miscarriages were added together (three, four, five, six, more than six), again no statistical difference was found between the osteopenia/osteoporosis group and the control group.

CONCLUSIONS

In postmenopausal women, the obstetric history of previous childbirths and/or miscarriages, independent of the number, did not seem to be a risk factor for osteopenia or osteoporosis.

Effect of parity on phalangeal bone mineral density in post-menopausal Sri Lankan women: a community based cross-sectional study

There is paucity of studies related to parity and bone mineral density in South Asian countries. We recruited 713 healthy, community dwelling post-menopausal women from seven provinces in Sri Lanka for this survey. The number of pregnancies, including miscarriages beyond 20 weeks of gestation, was recorded. Women with diseases and those who have taken drugs that can affect bone mineral density (BMD) were excluded (n = 15). Phalangeal BMD and bone mineral content (BMC) were measured using AccuDEXA in 713 women. Mean (SE) BMD of nulliparous women (n = 32), women with one to two pregnancies (n = 284), three to four pregnancies (n = 290) and more than four pregnancies (n = 107) were 0.437(0.014), 0.454(0.005), 0.455(0.005) and 0.417(0.006) g/cm(2), respectively (P < 0.001). Corresponding mean (SE) BMCs were 1.30(0.063), 1.41(0.021), 1.43(0.022) and 1.32(0.033) g, respectively (P < 0.001). Women with more than four pregnancies were older and lighter when compared with other groups. When results were adjusted for current age and current weight, differences in mean BMD and BMC between groups became non-significant. BMD of nulliparous women remained low in all analyses. We report a significant difference in unadjusted phalangeal BMD in women categorized according to their parity. Women with one to four pregnancies had the highest phalangeal BMD and BMC, while multi-parous (more than four pregnancies) and nulliparous women had lower values. However, in an adjusted analysis, the differences in BMD and BMC were partially explained by the differences of age and body weight between the groups and the unique effect of parity was difficult to determine. Women with lower BMD may have a higher risk of future fractures.

Bivariate genome-wide linkage analysis for traits BMD and AAM: effect of menopause on linkage signals

Osteoporosis is an age-related systemic skeletal disease, characterized by low bone mineral density (BMD). Low BMD is closely associated with late age at menarche (AAM). Our previous bivariate genome-wide linkage analyses (GWLAs) between BMD and AAM identified two shared genomic regions in 2584 Caucasian females including both pre- and post-menopausal females. However, menopause often causes dramatic bone loss in post-menopausal females; this may introduce some confounding effects on the bivariate GWLA for BMD and AAM. To address the effect of menopause on the identification of genetic factors shared by BMD and AAM, we segregated the previously studied population of 2584 females into two separate subgroups consisting of 1462 pre-menopause subjects and 1122 post-menopausal subjects, and performed further bivariate GWLAs. The BMD was measured by Hologic Dual-energy X-ray (DXA) scanners (Hologic Inc., Bedford, MA, USA). Based on the genome-wide thresholds corrected for multiple testing, we found more significant genomic regions in the pre-menopausal group than in total group (including pre- and post-menopausal women), e.g., we found 4, 1, and 2 shared by spine BMD and AAM, femoral neck (FNK) BMD and AAM and ultra distal (UD) BMD and AAM, respectively. We did not found any significant linkage signals in the post-menopausal group. Importantly, the linkage signals at all significant regions were much stronger in pre-menopausal group than in the other groups: post-menopausal females and total females. For example, the linkage LOD score for FNK BMD and AAM is as high as 4.88 in pre-menopausal females, but only 0.24 and 0.31 in post-menopausal and total females, respectively. These results suggest that menopause introduces some noise signals into GWLAs when estimating the shared genetic factors by BMD and AAM. Therefore, it is very important to classify female subjects properly according to their menopause stage when performing such studies.

Osteoporosis: Recommendations for Resistance Exercise and Supplementation With Calcium and Vitamin D to Promote Bone Health

Hormone replacement therapy, once the gold standard for treatment of osteoporosis, is no longer a clinical option. Effective alternatives are available using resistance exercise and supplementation with calcium and vitamin D to ameliorate bone loss and promote new bone formation. This article summarizes current evidence and provides recommendations for community health nurses to develop effective plans for prevention and treatment of osteoporosis.

Accelerated Decrease in Bone Mineral Density in Women Aged 52-57 Years

Bone mineral density (BMD) has been known to decline in middle-aged and elderly individuals, but when this decline begins and the rate at which it occurs remain unclear. We thus undertook this study to examine the association between BMD and age by their mean values in women visiting the Shimane Institute of Health Science for medical examination. We performed dual energy x-ray absorptiometry measurement of lumbar vertebrae in 1,167 women, and of the entire skeleton in 1,038 women. The ages of subjects ranged from 30 to 70 years. We found that the mean value of whole-body and lumbar BMD changed little in the age range of 30-51 years, and any change after 58 years was a gradual decrease, unlike the sharp decrease found between 52 and 57 years of age. The effects of endocrine kinetics may be reflected in women by the decrease of bone density relative to age. In conclusion, BMD declines more rapidly in women within the age range of 52-57 years than in those 58 years and over. This regression line is considered useful in predicting BMD of whole-body skeleton and lumbar vertebrae relative to age for the prevention of osteoporosis in women.