Exercise and reproductive factors as predictors of bone density among osteoporotic women in Mexico City

Is grand multiparity a risk factor for the development of postmenopausal osteoporosis?

Objective

In this study, we investigated the relationship between the development of postmenopausal osteoporosis and parity.

Materials and methods

The retrospective study included 129 postmenopausal women who were divided into three groups depending on the number of parity: Group I, <5; Group II, 5–9; and Group III, ≥10. The mean age of the subjects was 57.71±5.02 years.

Results

No significant difference was found among the three groups regarding body mass index values, duration of menopause, mean thyroid stimulating hormone values and frequency of diabetes. Among the three groups, no significant difference was found in terms of the frequency of lumbar osteoporosis (p>0.05), whereas a significant difference was found regarding the frequency of femoral osteoporosis (p=0.012; p<0.05).

Conclusion

It was revealed that femoral bone mineral density significantly decreased as the number of parity increased.

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.

Presentation and management of osteoporosis presenting in association with pregnancy or lactation

In this review, we summarize our current understanding of the pathophysiology of fragility fractures that occur for the first time during pregnancy and lactation, and provide guidance on appropriate investigations and treatment strategies. Most affected women will have had no prior bone density reading, and so the extent of bone loss that may have occurred during pregnancy or lactation is uncertain. During pregnancy, intestinal calcium absorption doubles in order to meet the fetal demand for calcium, but if maternal intake of calcium is insufficient to meet the combined needs of the mother and baby, the maternal skeleton will undergo resorption during the third trimester. During lactation, several hormonal changes, independent of maternal calcium intake, program a 5-10 % loss of trabecular mineral content in order to provide calcium to milk. After weaning the baby, the maternal skeleton is normally restored to its prior mineral content and strength. This physiological bone resorption during reproduction does not normally cause fractures; instead, women who do fracture are more likely to have additional secondary causes of bone loss and fragility. Transient osteoporosis of the hip may affect one or both femoral heads during pregnancy but it involves localized edema and not skeletal resorption. Case reports have described the use of calcitonin, bisphosphonates, strontium ranelate, teriparatide, vertebroplasty, and kyphoplasty to treat post-partum vertebral fractures. However, the need for such treatments is uncertain given that a progressive increase in bone mass subsequently occurs in most women who present with a fracture during pregnancy or lactation.

Supplementation of ascorbic acid and alpha-tocopherol is useful to preventing bone loss linked to oxidative stress in elderly

OBJECTIVE

To determine the effect of ascorbic acid and alpha-tocopherol on oxidative stress and bone mineral density (BMD) in elderly people.

DESIGN

A double-blind, controlled clinical assay was carried out in a sample of 90 elderly subjects divided into three age-paired random groups with 30 subjects in each group. Group Tx0 received placebo, group Tx1 received 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group Tx2 received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol, for a 12-month period.

MEASUREMENTS

We measured thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutation peroxidase (GPx); BMD was obtained on DXA of hip and spine before and after the 12-month treatment period with supplementation of vitamins C and E.

RESULTS

We found a positive correlation between hip-BMD and SOD (r = 0.298, p < 0.05) and GPx (r = 0.214, p < 0.05). Also, a significantly lower decrease of LPO (p < 0.05) was observed as linked with hip bone loss in the Tx2 group than in the Tx0 group.

CONCLUSIONS

Our findings suggest that that administration of 1,000 mg of ascorbic acid together with 400 IU of alpha-tocopherol could be useful in preventing or aiding in the treatment of age-related 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.

Role of exercise and nutrition in menopause

Menopause and the aging process itself cause many physiologic changes, which explain the increased prevalence of chronic diseases observed in postmenopausal women. Exercise and nutrition play important roles in the prevention and treatment of cardiovascular disease, cancer, obesity, diabetes, osteoporosis, and depression.

Body mass index and gynecological factors as determinants of bone mass in healthy Moroccan women

Several studies have shown that low body mass index (BMI) is associated with low BMD and fractures. However, the results that have been published from studies on reproductive factors and BMD are extremely controversial, with some demonstrating a beneficial effect, while others show a detrimental impact of these factors on bone mass.

OBJECTIVE

To study the influence of several gynecological factors (years since menopause (YSM), age at menarche and gynecological age or reproductive life) simultaneously with anthropometric factors as determinants of bone mineral density (BMD) in healthy women older than 40.

METHODS

BMD was determined by dual energy X-ray absorptiometry (DXA) at the lumbar spine and femurs in women aged >40 randomly chosen from the population of Rabat with a cluster sampling method.

RESULTS

Four hundred and twenty-two healthy women older than 40 years were included in the study. The mean age was 57.2 years (8.4) [40-79] and the mean number of parities was 4.42 (2.9) [0-14]. Osteoporosis according to the classification of WHO (T-score<or=-2.5) was observed in 133 women (32.2%). The increase in the number of parities was associated to a larger body mass index and a lower BMD as well in the hips and the lumbar spine after adjustment for age. The comparison of groups of patients according to the age at menarche, the age at menopause or the period of fertility did not highlight an association with BMD. BMD at the lumbar spine and the hips was correlated negatively with age, YSM and parity and positively with BMI. Multivariate analysis showed that the determinant of BMD are BMI (OR=0.88; 95% CI: 0.83-0.92), parity (OR=1.10; 1.01-1.56) and YSM (OR=1.06; 1.03-1.10).

CONCLUSION

Bone loss in women older than 40 is a function of aging, parity and years since menopause; and there is a definite bone-protective effect of body mass weight. Further studies are required to evaluate the role of these parameters in the fracture risk.

Symptoms, attitudes and treatment choices surrounding menopause among the Q'eqchi Maya of Livingston, Guatemala

The present study explored symptoms, attitudes and treatments surrounding women's health and menopause among the Q'eqchi Maya of the eastern tropical lowlands of Guatemala. Data were obtained through participant observation, semi-structured interviews, focus groups and plant walks with 50 Q'eqchi community members from the state of Izabal, Municipality of Livingston, including five midwives, five traditional male healers and eight postmenopausal women. Results indicate that the Q'eqchi Maya of Livingston possess their own cultural perceptions of women's health which affect attitudes, symptoms and treatment choices during the menopausal transition. Since discussions of menstruation and menopause are considered cultural taboos among the Q'eqchi, many women mentioned experiencing excessive preoccupation when unanticipated and unfamiliar symptoms occurred. Furthermore, many women suffered from additional hardship when their spouse misinterpreted menopausal symptoms (vaginal dryness, sexual disinterest) as infidelity. Seven of the eight postmenopausal women interviewed indicated experiencing one or more symptoms during the menopausal transition, including headaches, anxiety, muscular pain, depression, and hot flashes. These results differ from the lack of symptomatology reported in previous studies in Mexico, but are in line with the result of menopausal research conducted among other Maya groups from the highlands of Guatemala. Although the Q'eqchi did not use a specific term for "hot flash", three Q'eqchi women used the expression "baja presion" or a "lowering of blood pressure" to explain symptoms of profuse sweating followed by chills, heart palpitations, and emotional instability. The Q'eqchi Maya mentioned a number of herbal remedies to treat menopausal symptoms. Further research on these botanical treatments is needed in order to ascertain their safety and efficacy for continued use.

Age at natural menopause and factors associated with menopause state among Puerto Rican women aged 40-59 years, living in Puerto Rico

OBJECTIVE

The timing of menopause is associated with multiple health outcomes in female populations including all-cause mortality, heart disease, breast cancer, and osteoporosis. Although research suggests that age at menopause varies in different ethnic groups, data on age at menopause among Hispanic women are limited.

DESIGN

The present cross-sectional study estimates age at natural menopause among a sample of 1,272 Puerto Rican women aged 40 to 59 years who participated in health fairs held in 22 municipalities of Puerto Rico between May 2000 and November 2001. Cox proportional hazard regression analysis was used to characterize age at natural menopause and its association with relevant covariates.

RESULTS

The overall adjusted median age at natural menopause was 51.3 years. Current employment (hazard ratio = 0.75, 95% CI: 0.59-0.95) and parity of two or three children as compared with having no children or one child (hazard ratio = 0.73, 95% CI: 0.54-0.98) were associated with a later menopause.

CONCLUSIONS

This study provides a robust estimate of age at menopause for Puerto Rican women, which is similar to overall estimates previously reported for US populations, but higher than estimates for other Hispanic populations. Our results confirm attributes associated with age at menopause and provide information relevant to understanding the potential chronic disease burden of Puerto Rican women as they age.

The relationship between parity and bone mineral density in women characterized by a homogeneous lifestyle and high parity

CONTEXT

We reported previously that Old Order Amish (OOA) women have fewer hip fractures and higher bone mineral density (BMD) than non-Amish Caucasian women.

OBJECTIVE

The objective of this study was to determine whether the high parity characteristic of OOA women contributes to their relative bone health. Previous data on the long-term effects of parity on BMD have yielded conflicting results with few data from very high parity populations. This observational study included participants in the Amish Family Osteoporosis Study, begun in 1997 to identify genetic and clinical determinants of osteoporosis in the OOA. We measured BMD by dual-energy x-ray absorptiometry at the spine, hip, and distal radius in 424 parous OOA women aged 40 and older (mean age, 57.7 +/- 12 yr; mean parity, 7.6 +/- 2.9).

RESULTS

Increasing parity was associated with later menopause (P = 0.001) and modestly, but not significantly, higher body mass index (BMI) (P = 0.09). Increasing parity was associated with higher BMD at the total hip and trochanter (age-adjusted P = 0.02 and 0.03), no longer statistically significant after accounting for BMI. Among women aged 50-59 yr, parity was strongly associated with BMD even after accounting for age and BMI (age-adjusted P = 0.02), although this was not true for women younger than 50 or at least 60 yr old.

CONCLUSIONS

We conclude that high parity is associated with increased hip BMD in OOA women, largely mediated by higher BMI. The parity-hip BMD association remained statistically significant after accounting for age and BMI only in women aged 50-59 yr, partially explained by a later menopausal age with high parity. The benefit of high parity on BMD appeared to be lost soon after the menopausal transition, and, therefore, these data provide evidence of neither a detrimental nor beneficial effect of high parity on long-term bone health.

Predictors of bone mineral density in female workers in Morelos State, Mexico

BACKGROUND

Although several studies have identified factors associated with bone mineral density (BMD), little research is available on Mexican women.

METHODS

A cross-sectional study was conducted in 1,622 female workers between 20 and 80 years of age at the Mexican Social Security Institute (IMSS), an integral part of the Mexican health system. It was carried out in Morelos, a Mexican state that borders Mexico City. Women were recruited to participate in this study from their workplaces. Body mass index (BMI) was measured and BMD was assessed using dual-energy x-ray absorptiometry of dominant forearm. Predictors of BMD (age, reproductive factors, BMI, diet, and physical activity) in pre- and postmenopausal women were assessed by questionnaire and analyzed using generalized additive models.

RESULTS

In premenopausal women, older age, higher BMI, younger age at menarche, and greater vitamin D intake were associated with higher BMD (R(2)=0.06, null deviance reduction=6.9%). In postmenopausal women, determinants of BMD were older age, higher BMI, greater height, later initiation of menopause, longer time of use of hormonal replacement therapy (HRT), and greater calcium intake from dairy products (R(2)=0.39, null deviance reduction=40.7%).

CONCLUSIONS

As observed in other populations, age, BMI, height, age at menopause, time of use of HRT, and calcium intake derived from dairy products in these Mexican women are factors associated with higher forearm BMD during postmenopausal period. Age, BMI, age at menarche, and vitamin D are associated with higher forearm BMD in premenopausal women. Some of these factors are not linearly associated with BMD. This was a limited population study carried out in a large group of female healthcare workers whose reproductive and lifestyle factors potentially agreed with those of female workers from urban areas of Mexico.

Effect of parity on bone mineral density in female rhesus macaques from Cayo Santiago

This cross-sectional study investigates the relationship between parity, bone mineral density, and spontaneous osteopenia/osteoporosis in a large skeletal population of female rhesus macaques (Macaca mulatta) from the free-ranging colony of Cayo Santiago, Puerto Rico. The sample consists of 119 mature female monkeys aged 4.0-22.2 years at time of death. The data consist of measurements of bone mineral content (BMC) and bone mineral density (BMD), obtained from dual-energy X-ray absorptiometry (DEXA) of the last lumbar vertebra. After controlling for age, there is a significant increase in BMD of the spine with increasing parity (P = 0.0006), up to a parity of 7 offspring. Thus, high parity initially has a positive effect on BMD in female rhesus monkeys, but this positive effect disappears with parities that are greater than 7 offspring. After controlling for parity, however, age has a negative (P = 0.015) effect on BMD, beginning several years after the attainment of peak BMD (age 9.5 years). Thus, it appears that parity initially mitigates the effects of aging, but the positive effect of parity on BMD is eventually overwhelmed by the aging process. Mean BMC and BMD values are higher in parous females compared to nulliparous females in the same age range. Similarly, females with low parity have significantly lower mean BMD values than do age-matched high-parity controls, and the frequency of osteopenia and osteoporosis is greater in low-parity females. Forty-three percent (43%) of the osteopenic/osteoporotic females in the sample are members of the low-parity group, even though it composes only 13% (16/119) of the entire sample. This study demonstrates that the free-ranging female rhesus monkeys from Cayo Santiago are a good nonhuman primate model for the study of bone mineral density, parity, osteopenia, and osteoporosis.

Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study

BACKGROUND

The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear.

OBJECTIVE

We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women.

DESIGN

We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y. Analyses were performed on 3 data sets: study 1, 83 female twin pairs (21 monozygous and 62 dizygous) aged (x +/- SD) 42.2 +/- 15.5 y who were discordant for ever having been pregnant beyond 20 wk; study 2, 498 twin pairs aged 42.3 +/- 15.0 y; and study 3, 1354 individual twins, their siblings, and family members.

RESULTS

In study 1, there were no significant within-pair differences in unadjusted BMD or BMD adjusted for age, height, and fat mass at the lumbar spine or total-hip or in total-body bone mineral content (BMC; kg) (paired t tests). In study 2, there was no significant within-pair difference in measures of bone mineral or body composition related to the within-pair difference in number of pregnancies. In study 3, subjects with 1 or 2 (n = 455) and > or = 3 pregnancies (n = 473) had higher adjusted lumbar spine BMD (2.9% and 3.8%, respectively; P = 0.001) and total-body BMC (2.2% and 3.1%; P < 0.001) than did nulliparous women (n = 426). Parous women who breast-fed had higher adjusted total-body BMC (2.6%; P = 0.005), total-hip BMD (3.2%; P = 0.04), and lower fat mass (10.9%; P = 0.01) than did parous non-breast-feeders.

CONCLUSION

We found no long-term detrimental effect of pregnancy or breast-feeding on bone mineral measures.

Risk factors for hysterectomy among Mexican-American women in the US southwest

The purpose of this study was to assess risk factors associated with a history of hysterectomy among Mexican-American women living in the United States Southwest. Mexican-American women ages 20-74 at time of interview were defined as a subpopulation among adults in the Hispanic Health and Nutrition Examination Survey (HHANES), 1982-1984. Language preference, reproductive history, level of education, poverty status, generation of immigration, marital status, and insurance coverage were examined in relation to risk of hysterectomy using weighted tabulation and logistic regression for data resulting from complex survey designs. Heretofore, language preference has not been a variable considered in relation to risk of hysterectomy. In the HHANES, over 60% of women who spoke English most often rather than Spanish reported a history of hysterectomy. Women who had previously been pregnant were almost four times as likely (odds ratio 3.972) to have had a hysterectomy compared to women who had never been pregnant. Women who expressed any preference for English were twice as likely (odds ratio 2.050) to have had a hysterectomy than were those who responded that they exclusively preferred Spanish. Age, higher levels of education, and higher economic status also increased the risk of hysterectomy. In contrast, reproductive history, marital status, prior tubal ligation, generation of immigration, and health insurance did not have substantial effects on the risk of hysterectomy. This study suggests that, in the future, the effect of language preference should not be overlooked when considering risk factors for hysterectomy.

Validity of bone mineral density measurements in distal sites as an indicator of total bone mineral density in a group of pre-adolescent and adolescent women

BACKGROUND

The study of bone mineral density (BMD) has received attention due to the importance of osteoporosis as a public health problem in Mexico. The objective of this study was to assess the validity of BMD measures in distal forearm and calcaneus with portable densitometers as indicators of BMD on other anatomic sites.

METHODS

We conducted a cross-sectional study with 219 women from 9 to 22 years of age in Cuernavaca, Morelos, Mexico. We measured BMD in central sites (the entire skeleton, excluding head, proximal femur, and lumbar spine) using dual X-ray absorptiometry (DXA) and in peripheral sites (distal forearm and calcaneus) using a portable densitometer with DXA technology. Measurements of height, weight, body composition, physical activity, and demographic characteristics were collected. Agreement of measurements of BMD was assessed using correlation and regression analysis, and the method proposed by Bland and Altman.

RESULTS

Higher levels of BMD were found in total skeleton (0.88 g/cm(2)) than in calcaneus (0.48 g/cm(2)) and distal forearm (0.38 g/cm(2)) (p <0.05). Moderate-to-high positive correlation coefficients (all significant) (p <0.05) were found between BMD in distal forearm and calcaneus vs. central anatomic sites, ranging from r = 0.49 to r = 0.78. BMD was higher in central sites compared with distal forearm and calcaneus.

CONCLUSIONS

Measurement of BMD in distal forearm and calcaneus with portable densitometers provided valid indicators of BMD in central anatomic sites among pre-adolescent and adolescent women in Mexico.

Postmenopausal function in context: biocultural observations on Amish, neighboring non-Amish, and Ifugao household health

Ecological approaches to female post-reproductive function must consider the social context and microenvironment of the household. A model integrating these environmental factors into the analysis of late-life well-being (operationally defined as household health) is presented and explored in three settings: an Old Order Amish community, the neighboring community of non-Amish, and an Ifugao community in the Philippine highlands. Intensive interview and observation of function were completed in a sample of at least 25 households in each community. The complex interaction of social and biological factors is explored in case studies and through multiple regression analysis with household health as the dependent variable. The results emphasize the importance of social support and assessing capabilities within the household. The results also suggest the need for natural field observation of work to better understand the influence of pacing and scheduling, necessity of work, and the role of environmental modification in postmenopausal function.

Higher milk intake during pregnancy is associated with lower maternal and umbilical cord lead levels in postpartum women

Lead exposure and its deleterious effects continue to be a problem in many countries. The lack of effective and safe treatments for low-level intoxication has promoted environmental interventions to control different sources of lead. In this study we evaluated the effect of milk consumption in 1849 mother-and-child pairs participating in the lead surveillance program in Mexico City. The mean lead levels were 11.2 micrograms/dL for maternal blood lead (MBL) and 10.8 micrograms/dL in umbilical cord. The correlation between blood lead and umbilical cord lead was r = 0.74. Forty-eight percent of the MBL exceeded 10 micrograms/dL and 9.5% exceeded 20 micrograms/dL. Maternal blood lead was positively related to the use of lead-glazed ceramic were and to traffic exposure and was inversely related to the consumption of milk and orange juice. Women who reported the consumption of more than 7 glasses of milk per week had a blood lead level of 8.7 micrograms/dL; in comparison, those women who reported a consumption of less than 7 glasses per week had a blood lead level of 11.1 micrograms/dL. Similar findings were observed for lead measured in umbilical cord. The association between lead levels and milk intake remained unchanged after taking in consideration other predictors of blood lead. This study suggests that a simple intervention could reduce lead burden among women and their newborns.