Lactation is associated with greater maternal bone size and bone strength later in life

Interventions and Programs to Promote Breastfeeding in Arabic-Speaking Countries: A Scoping Review

INTRODUCTION

Low prevalence of exclusive breastfeeding in the Arab world is concerning and suboptimal breastfeeding is a leading child health risk factor in several Arab States. Breastfeeding education has the capacity to improve breastfeeding knowledge and practice, thus positively impacting infant and maternal health. The purpose of this review is to identify and examine the impact of breastfeeding promotion interventions across the Arab world.

METHOD

A scoping review of the literature was conducted across seventeen databases for relevant publications published through October 2021 to find studies in Arab countries, that involved breastfeeding as an intervention component. Twenty-one articles met inclusion criteria and were reviewed.

RESULTS

Individual and community based educational interventions offer the opportunity to positively impact the knowledge, attitudes, and practices of breastfeeding in new mothers in Arab countries. Increased breastfeeding has the potential to lead to improved neonate and maternal health. In addition to significant benefits found across individual and community-based interventions in a variety of Arab countries, there is also evidence that interventions that improve the knowledge of health care professionals and/or the practices of a health care system can contribute to subsequent increases in breastfeeding rates.

DISCUSSION

Breastfeeding education is a low-cost and high-impact public health tool that can impact infant and maternal health and potentially increase breastfeeding adherence in the Arab world.

Impact of Adolescent Pregnancy on Bone Density in Underprivileged Pre-Menopausal Indian Women

High prevalence (31.5%) of adolescent pregnancies (AP) have been reported in India. Reports suggest that pregnancy during adolescence may have deleterious effects on peak bone mass. Very few studies have described the long-term effects of a history of AP on bone mass. The objective of this study was to compare bone mineral density (BMD) and bone geometry of premenopausal women with first childbirth during adolescence (i.e., before age of 19 years) or after 20 years. A cross-sectional study was conducted in 242 women (age 28.0-54.5 years) from Pune, India (November, 2015 to November, 2017). Women were divided into 2-groups: Group-1: women-who had 1st-pregnancy and childbirth before 19 years of age (AP n = 131) and Group-2: women-who had 1st pregnancy after 20 years of age (non-AP n = 111). Demographic data, anthropometric measurements, and biochemical tests were performed using standard protocols. Physical activity and nutrient intakes were recorded using validated questionnaires. Areal BMD and bone geometry were measured using Dual-Energy-Absorptiometry-DXA (Lunar-iDXA, GE Healthcare) and peripheral-quantitative-computed-tomography-pQCT (XCT2000, Stratec Inc.). Mean age of the study group was 37 ± 4.6 years; in women from group-1 mean age at first delivery was 16.9 ± 1.6 years as against 22.6 ± 3.1 years in group-2. Both groups were similar in body mass index and socioeconomic status. pQCT measured radial diaphyseal cortical thickness (1.97 ± 0.3 mm vs 1.88 ± 0.3 mm resp., p = 0.016, periosteal circumference (38.0 ± 3.6 mm vs 36.7 ± 2.5 mm, resp. p = 0.016), total bone area (114.3 ± 24.8 mm² vs 108.7 ± 14.7 mm² resp. p = 0.026) and stress-strain index (SSI = 217 ± 75 vs 201 ± 40 mm³ resp. p = 0.042) were significantly higher in group-1 than group-2. After adjusting for anthropometric and lifestyle parameters, pQCT measured cortical thickness (1.98 ± 0.03 mm in group-1, 1.87 ± 0.03 mm group-2, p = 0.01, mean ± SE) and iDXA derived aBMD at forearm were still significantly higher (0.599 ± 0.006 g/cm3 vs 0.580 ± 0.006 g/cm3, p = 0.023) in Group-1. Our data suggest that women with a history of adolescent pregnancy had better bone geometry and higher aBMD at radius in later years. We speculate that early exposure to pregnancy resulted in higher aBMD at the radius and induced changes at radial diaphysis with bones becoming thicker and wider among these women.

Lactation alters fluid flow and solute transport in maternal skeleton: A multiscale modeling study on the effects of microstructural changes and loading frequency

The female skeleton undergoes significant material and ultrastructural changes to meet high calcium demands during reproduction and lactation. Through the peri-lacunar/canalicular remodeling (PLR), osteocytes actively resorb surrounding matrix and enlarge their lacunae and canaliculi during lactation, which are quickly reversed after weaning. How these changes alter the physicochemical environment of osteocytes, the most abundant and primary mechanosensing cells in bone, are not well understood. In this study, we developed a multiscale poroelastic modeling technique to investigate lactation-induced changes in stress, fluid pressurization, fluid flow, and solute transport across multiple length scales (whole bone, porous midshaft cortex, lacunar-canalicular pore system (LCS), and pericellular matrix (PCM) around osteocytes) in murine tibiae subjected to axial compression at 3 N peak load (~320 με) at 0.5, 2, or 4 Hz. Based on previously reported skeletal anatomical measurements from lactating and nulliparous mice, our models demonstrated that loading frequency, LCS porosity, and PCM density were major determinants of fluid and solute flows responsible for osteocyte mechanosensing, cell-cell signaling, and metabolism. When loaded at 0.5 Hz, lactation-induced LCS expansion and potential PCM reduction promoted solute transport and osteocyte mechanosensing via primary cilia, but suppressed mechanosensing via fluid shear and/or drag force on the cell membrane. Interestingly, loading at 2 or 4 Hz was found to overcome the mechanosensing deficits observed at 0.5 Hz and these counter effects became more pronounced at 4 Hz and with sparser PCM in the lactating bone. Synergistically, higher loading frequency (2, 4 Hz) and sparser PCM enhanced flow-mediated mechanosensing and diffusion/convection of nutrients and signaling molecules for osteocytes. In summary, lactation-induced structural changes alter the local environment of osteocytes in ways that favor metabolism, mechanosensing, and post-weaning recovery of maternal bone. Thus, osteocytes play a role in balancing the metabolic and mechanical functions of female skeleton during reproduction and lactation.

Validation of the Arabic Maternal Breastfeeding Evaluation Scale (MBFES-A) among Lebanese women

Background

Maternal satisfaction with the breastfeeding experience is an important determinant of breastfeeding success. There is currently no valid tool to measure perceived maternal satisfaction with breastfeeding in the Arab context.

Methods

This cohort study tested the Maternal Breastfeeding Evaluation Scale (MBFES) on 450 healthy Lebanese mothers for internal consistency reliability and construct validity. Participants were recruited between April 2018 and February 2020.

Results

The Cronbach’s alpha reliability coefficient of the Arabic MBFES (MBFES-A) was 0.87. Exploratory factor analysis revealed that it has three components: Infant Satisfaction/Growth, Maternal Enjoyment/Role Attainment, and Lifestyle/Body Image with reliability coefficients of 0.88, 0.87, and 0.68, respectively. Four items were deleted because of low factor loadings and three items were relocated to the Infant Satisfaction/Growth subscale based on their factor loadings. Participants who were exclusively breastfeeding at one and/or 3 months had higher mean MBFES-A total and Infant Satisfaction/Growth and Maternal Enjoyment/Role Attainment subscale scores than participants who were partially breastfeeding, and significantly higher mean scores than mothers who were not breastfeeding (all p values < 0.001), findings that support the scale’s construct validity. Moreover, scores on the Infant Satisfaction/Growth subscale correlated with exclusive breastfeeding at one (r = 0.37, p < 0.001) and 3 months (r = 0.31, p < 0.001). The MBFES-A score had positive modest correlations with maternal attitude towards breastfeeding (r = 0.30, p < 0.001), exclusive breastfeeding at one (r = 0.27) and at 3 months (r = 0.26, p < 0.001 for both), as well as with the longest previous exclusive breastfeeding (r = 0.27, p < 0.001).

Conclusions

The 26-item MBFES-A is a reliable and valid instrument to use in future breastfeeding research in Middle East North Africa countries. There is a need for replication of our findings in other Arab contexts using new constructs to establish stronger construct validity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13006-021-00409-w.

Pathways linking activity, adiposity, and inflammation to bone mineral density in women and men from NHANES 2007 to 2010

OBJECTIVES

Age, sedentary activity, central adiposity, and inflammation have all been independently associated with bone mineral density (BMD). We assessed how the effects of sedentary activity and central adiposity on BMD of the lumbar spine and femoral neck change across early to late adulthood and whether these relationships are mediated by inflammation.

METHODS

We analyzed data from 7135 women and men 20 years of age and older from NHANES 2007 to 2010. Anthropometrics, sedentary activity (min/day), serum CRP (mg/dl), and BMD (gm/cm² measured by DXA scans) at the femoral neck and lumbar spine. Data were compared by age and sex groups and through causal mediation analysis.

RESULTS

The effect of waist circumference on BMD was significantly mediated by serum CRP at both skeletal sites in men and at the femoral neck in women. Sedentary activity did not have a direct relationship to BMD but was mediated by waist circumference in men. Least square means differed significantly by sex and age groups with a general age-related decline in BMD at both skeletal sites.

CONCLUSIONS

We found that central adiposity, independent of overall body size and composition as measured through BMI, has an inverse relationship with BMD that is mediated by serum CRP. In addition, the negative impact of increased sedentism acted through changes in central adiposity (waist circumference) but only in men. Although low bone density and osteoporosis are often considered degenerative diseases that primarily impact postmenopausal women, our findings show that sedentary activity and central adiposity impact bone density beginning in early adulthood in both women and men.

Pregnancy and lactation, a challenge for the skeleton

In this review we discuss skeletal adaptations to the demanding situation of pregnancy and lactation. Calcium demands are increased during pregnancy and lactation, and this is effectuated by a complex series of hormonal changes. The changes in bone structure at the tissue and whole bone level observed during pregnancy and lactation appear to largely recover over time. The magnitude of the changes observed during lactation may relate to the volume and duration of breastfeeding and return to regular menses. Studies examining long-term consequences of pregnancy and lactation suggest that there are small, site-specific benefits to bone density and that bone geometry may also be affected. Pregnancy- and lactation-induced osteoporosis (PLO) is a rare disease for which the pathophysiological mechanism is as yet incompletely known; here, we discuss and speculate on the possible roles of genetics, oxytocin, sympathetic tone and bone marrow fat. Finally, we discuss fracture healing during pregnancy and lactation and the effects of estrogen on this process.

Associations Between Breastfeeding History and Early Postmenopausal Bone Loss

This study aimed to evaluate associations of parity and breastfeeding history with postmenopausal bone loss. Early postmenopausal women from the Canadian Multicentre Osteoporosis Study were divided into three groups based on their reproductive histories: nulliparous (NP, n = 10), parous with < 6 months breastfeeding (P-NBF, n = 14), and parous with > 6 months breastfeeding (P-BF, n = 21). Women underwent dual X-ray absorptiometry and high-resolution peripheral quantitative computed tomography imaging at baseline and after 6 years to evaluate bone mineral density (BMD), bone microstructure, and finite element-estimated failure load. Average age at baseline was 57 years. Baseline density, microstructure, and failure load were not different among groups. In all women, total and cortical BMD decreased significantly at the tibia and radius. P-BF women only experienced a significant decline in tibial trabecular BMD, with a greater magnitude of change for P-BF than NP women (p = 0.002). Overall, results suggest that early postmenopausal bone health did not differ based on parity or breastfeeding history. Over the 6-year follow-up period, postmenopausal bone loss was evident in all women, with subtle differences in the rate of postmenopausal change among women with varying breastfeeding histories. Parous women who had breastfed for at least 6 months showed an elevated rate of trabecular BMD loss at the tibia. Meanwhile, correlation analyses suggest that longer durations of breastfeeding may be associated with reduced cortical bone loss at the radius. The lack of differences among groups in FE-derived failure load suggests that parity and breastfeeding history is unlikely to significantly affect postmenopausal risk of fracture.

How does women's bone health recover after lactation? A systematic review and meta-analysis

This is a systematic review aiming to evaluate the recovery of bone mass after lactation-related loss. Bone loss is transitory with recovery depending on the return of menstruation and weaning, and several compensatory homeostatic mechanisms are involved to minimize any significant damage to the maternal skeleton. Lactation has been associated with significant temporary bone loss, especially during the exclusive breastfeeding period. In the bone recovery phase, there is wide methodological heterogeneity among clinical trials, including follow-up timing, methods and sites of bone measurements, and body composition changes. The purpose of this study is to perform a systematic review and meta-analysis aiming to evaluate the recovery rate of bone mass after lactation-related loss, including the PubMed, Web of Science, and Scopus databases, with no publication date restrictions. The following MeSH terms were used: "bone diseases," "bone resorption," "bone density," "osteoporosis," "calcium," "postpartum period," "weaning," "breast feeding," and "lactation." The inclusion criteria were as follows: prospective human studies in women of reproductive age and bone measurements with two assessments in the postpartum period at least: the first one within the first weeks of lactation and another one 12 months after delivery, 3 months following the return of menses or 3 months postweaning. This research was recorded on the Prospero database (CRD42018096586Bone). A total of 9455 studies were found and 32 papers met the inclusion criteria. The follow-up period ranged from one to 3.6 years postpartum. Lactation was associated with transient bone loss, with a strong tendency to recover in all the sites studied, depending on the return of menstruation and weaning. Small deficits in the microarchitecture of the peripheral skeleton may be present, especially in women with prolonged breastfeeding, but with no deficit regarding the hip geometry was found. Women with a successive gestation after prolonged lactation and women who had breastfed when adolescents had no significant bone loss. Bone loss related to lactation is transitory, and several compensatory homeostatic mechanisms are involved to minimize any significant damage to the maternal skeleton.

Mechanical Regulation of the Maternal Skeleton during Reproduction and Lactation

PURPOSE OF REVIEW

This review summarizes recently published data on the effects of pregnancy and lactation on bone structure, mechanical properties, and mechano-responsiveness in an effort to elucidate how the balance between the structural and metabolic functions of the skeleton is achieved during these physiological processes.

RECENT FINDINGS

While pregnancy and lactation induce significant changes in bone density and structure to provide calcium for fetal/infant growth, the maternal physiology also comprises several innate compensatory mechanisms that allow for the maintenance of skeletal mechanical integrity. Both clinical and animal studies suggest that pregnancy and lactation lead to adaptations in cortical bone structure to allow for rapid calcium release from the trabecular compartment while maintaining whole bone stiffness and strength. Moreover, extents of lactation-induced bone loss and weaning-induced recovery are highly dependent on a given bone's load-bearing function, resulting in better protection of the mechanical integrity at critical load-bearing sites. The recent discovery of lactation-induced osteocytic perilacunar/canalicular remodeling (PLR) indicates a new means for osteocytes to modulate mineral homeostasis and tissue-level mechanical properties of the maternal skeleton. Furthermore, lactation-induced PLR may also play an important role in maintaining the maternal skeleton's load-bearing capacity by altering osteocyte's microenvironment and modulating the transmission of anabolic mechanical signals to osteocytes. Both clinical and animal studies show that parity and lactation have no adverse, or a positive effect on bone strength later in life. The skeletal effects during pregnancy and lactation reflect an optimized balance between the mechanical and metabolic functions of the skeleton.

Associations of Breastfeeding Duration and Reproductive Factors with Sarcopenia in Elderly Korean Women: A Cross-Sectional Study from the Korea National Health and Nutrition Examination Survey 2010–2011

Background

Several studies have suggested that breastfeeding has a positive effect on long-term obesity, diabetes, hypertension, and hyperlipidemia. This study aimed to examine maternal bone health, muscle mass, and obesity based on breastfeeding duration.

Methods

This study was based on the Korea National Health and Nutrition Examination Survey 2010–2011. We selected 2,027 elderly women by screening survey participants with a history of delivery. Multivariate logistic regression analyses were performed to estimate the odds ratios (ORs) of sarcopenia, osteoporosis, and obesity among four breastfeeding groups.

Results

The OR of sarcopenia significantly decreased with increasing breastfeeding duration (OR, 0.27; 95% confidence interval [CI], 0.11–0.65; P for trend <0.001), whereas the OR of obesity significantly increased with increasing breastfeeding duration (OR, 2.56; 95% CI, 1.43–4.60; P for trend=0.009) after adjusting for potential confounding variables. We also found a positive correlation between the duration since last delivery and sarcopenia.

Conclusion

Our results suggest a negative correlation between prolonged breastfeeding and the prevalence of sarcopenia, and a positive correlation between prolonged breastfeeding and the prevalence of obesity. Further studies are needed to clarify the relationship between breastfeeding and sarcopenia in the future.

Parity and lactation are not associated with incident fragility fractures or radiographic vertebral fractures over 16 years of follow-up: Canadian Multicentre Osteoporosis Study (CaMos)

Parity and lactation showed no associations with incident clinical fragility fractures or radiographic vertebral compression fractures in the 16-year CaMos prospective study. Parity was associated with slightly greater decline in femoral neck but not hip or spine areal bone mineral density (aBMD), while lactation showed no associations with aBMD change.

PURPOSE

Pregnancy and especially lactation cause loss of bone mass and microarchitectural changes, which temporarily increase fracture risk. After weaning, aBMD increases but skeletal microarchitecture may be incompletely restored. Most retrospective clinical studies found neutral or even protective associations of parity and lactation with fragility fractures, but prospective data are sparse. CaMos is a randomly selected observational cohort that includes ~ 6500 women followed prospectively for over 16 years.

METHODS

We determined whether parity or lactation were related to incident clinical fragility fractures over 16 years, radiographic (morphometric and morphologic) vertebral fractures over 10 years, and aBMD change (spine, total hip, and femoral neck) over 10 years. Parity and lactation duration were analyzed as continuous variables in predicting these outcomes using univariate and multivariate regression analyses.

RESULTS

Three thousand four hundred thirty-seven women completed 16 years of follow-up for incident clinical fractures, 3839 completed 10 years of morphometric vertebral fracture assessment, 3788 completed 10 years of morphologic vertebral fracture assessment, and 4464 completed 10 years of follow-up for change in aBMD. In the multivariate analyses, parity and lactation duration showed no associations with clinical fragility fractures, radiographic vertebral fractures, or change in aBMD, except that parity associated with a probable chance finding of a slightly greater decline in femoral neck aBMD.

CONCLUSIONS

Parity and lactation have no adverse associations with clinical fragility or radiographic vertebral fractures, or the rate of BMD decline over 10 years, in this prospective, multicenter study of a randomly selected, population-based cohort of women.

Structural Adaptations in the Rat Tibia Bone Induced by Pregnancy and Lactation Confer Protective Effects Against Future Estrogen Deficiency

The female skeleton undergoes substantial structural changes during the course of reproduction. Although bone mineral density recovers postweaning, reproduction may induce permanent alterations in maternal bone microarchitecture. However, epidemiological studies suggest that a history of pregnancy and/or lactation does not increase the risk of postmenopausal osteoporosis or fracture and may even have a protective effect. Our study aimed to explain this paradox by using a rat model, combined with in vivo micro-computed tomography (μCT) imaging and bone histomorphometry, to track the changes in bone structure and cellular activities in response to estrogen deficiency following ovariectomy (OVX) in rats with and without a reproductive history. Our results demonstrated that a history of reproduction results in an altered skeletal response to estrogen-deficiency-induced bone loss later in life. Prior to OVX, rats with a reproductive history had lower trabecular bone mass, altered trabecular microarchitecture, and more robust cortical structure at the proximal tibia when compared to virgins. After OVX, these rats underwent a lower rate of trabecular bone loss than virgins, with minimal structural deterioration. As a result, by 12 weeks post-OVX, rats with a reproductive history had similar trabecular bone mass, elevated trabecular thickness, and increased robustness of cortical bone when compared to virgins, resulting in greater bone stiffness. Further evaluation suggested that reproductive-history-induced differences in post-OVX trabecular bone loss were likely due to differences in baseline trabecular microarchitecture, particularly trabecular thickness. Rats with a reproductive history had a larger population of thick trabeculae, which may be protective against post-OVX trabecular connectivity deterioration and bone loss. Taken together, these findings indicate that reproduction-associated changes in bone microarchitecture appear to reduce the rate of bone loss induced by estrogen deficiency later in life, and thereby exert a long-term protective effect on bone strength. © 2018 American Society for Bone and Mineral Research.

Reproduction triggers adaptive increases in body size in female mole-rats

In social mole-rats, breeding females are larger and more elongated than non-breeding female helpers. This status-related morphological divergence is thought to arise from modifications of skeletal growth following the death or removal of the previous breeder and the transition of their successors from a non-breeding to a breeding role. However, it is not clear what changes in growth are involved, whether they are stimulated by the relaxation of reproductive suppression or by changes in breeding status, or whether they are associated with fecundity increases. Here, we show that, in captive Damaraland mole-rats (Fukomys damarensis), where breeding was experimentally controlled in age-matched siblings, individuals changed in size and shape through a lengthening of the lumbar vertebrae when they began breeding. This skeletal remodelling results from changes in breeding status because (i) females removed from a group setting and placed solitarily showed no increases in growth and (ii) females dispersing from natural groups that have not yet bred do not differ in size and shape from helpers in established groups. Growth patterns consequently resemble other social vertebrates where contrasts in size and shape follow the acquisition of the breeding role. Our results also suggest that the increases in female body size provide fecundity benefits. Similar forms of socially responsive growth might be more prevalent in vertebrates than is currently recognized, but the extent to which this is the case, and the implications for the structuring of mammalian dominance hierarchies, are as yet poorly understood.

Breastfeeding and the Benefits of Lactation for Women's Health

The offer of the maternal breast to the baby is an unquestionable right of mothers and their children, and all efforts should be made to promote, follow and maintain exclusive breastfeeding for up to 6 months and supplement it until the child completes 2 years of age. Many publications are available in the literature about the qualities of breast milk, its benefits and health repercussions, stimulating the practice of breastfeeding and supporting campaigns for its implementation. However, although it is widely known that breastfeeding is an important step in the reproductive process of women and its practice offers benefits to both mother and child, most of the available information highlights the benefits of breast milk for children, while mention of the effects of breastfeeding on the health of the mother is usually neglected. Thus, the objective of the present study is to highlight the multiple benefits of breastfeeding for the physical and emotional health of the nursing mother. The authors consulted articles published in the databases PubMed, Virtual Health Library and Web of Science using the keywords breastfeeding, breast milk, lactation and maternal health.

Could use of Selective Serotonin Reuptake Inhibitors During Lactation Cause Persistent Effects on Maternal Bone?

The lactating mammary gland elegantly coordinates maternal homeostasis to provide calcium for milk. During lactation, the monoamine serotonin regulates the synthesis and release of various mammary gland-derived factors, such as parathyroid hormone-related protein (PTHrP), to stimulate bone resorption. Recent evidence suggests that bone mineral lost during prolonged lactation is not fully recovered following weaning, possibly putting women at increased risk of fracture or osteoporosis. Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants have also been associated with reduced bone mineral density and increased fracture risk. Therefore, SSRI exposure while breastfeeding may exacerbate lactational bone loss, compromising long-term bone health. Through an examination of serotonin and calcium homeostasis during lactation, lactational bone turnover and post-weaning recovery of bone mineral, and the effect of peripartum depression and SSRI on the mammary gland and bone, this review will discuss the hypothesis that peripartum SSRI exposure causes persistent reductions in bone mineral density through mammary-derived PTHrP signaling with bone.

Reproductive factors influencing bone mineral density in postmenopausal women

This study examined the relationship between reproductive characteristics and bone mineral density (BMD) in postmenopausal women who had been referred to the menopause clinics of the National Population and Family Development Board and of the Hospital Kuala Lumpur from July 2011 to January 2012. The participants of this study were 201 postmenopausal Malaysian women aged 45-71 years. Some socio-demographic, lifestyle, and reproductive factors were recorded. Calcaneal BMD was measured by quantitative ultra-sonography. Correlations of reproductive factors with BMD were assessed by Pearson's correlation test and multiple regression analysis. Age at menopause was not significantly correlated with BMD, while the years after menopause, age at the first menstrual period, number of pregnancies, and total lactation periods were inversely correlated with it. Among reproductive factors, only the association between lactation duration and BMD remained significant after adjusting for age, body mass index, activity, and calcium intake. The results indicated that except for prolonged total time of lactation, other reproductive factors were not significantly associated with BMD in postmenopausal women.

Molecular Modulation of Osteoblasts and Osteoclasts in Type 2 Diabetes

Diabetes is a common disease affecting majority of populations worldwide. Since 1980, there has been an increase in the number of people diagnosed as prediabetic and diabetic. Diabetes is characterized by high levels of circulating glucose and leads to most microvascular and macrovascular complications such as retinopathy, nephropathy, neuropathy, stroke, and myocardial infarction. Bone marrow vascular disruption and increased adiposity are also linked to various complications in type II diabetes mellitus. In addition to these complications, type 2 diabetic patients also have fragile bones caused by faulty mineralization mainly due to increased adiposity among diabetic patients that affects both osteoblast and osteoclast functions. Other factors that increase fracture risk in diabetic patients are increased oxidative stress, inflammation, and drugs administered to diabetic patients. This review reports the modulation of different pathways that affect bone metabolism in diabetic conditions.

Adaptations in the Microarchitecture and Load Distribution of Maternal Cortical and Trabecular Bone in Response to Multiple Reproductive Cycles in Rats

Pregnancy, lactation, and weaning result in dramatic changes in maternal calcium metabolism. In particular, the increased calcium demand during lactation causes a substantial degree of maternal bone loss. This reproductive bone loss has been suggested to be largely reversible, as multiple clinical studies have found that parity and lactation history have no adverse effect on postmenopausal fracture risk. However, the precise effects of pregnancy, lactation, and post-weaning recovery on maternal bone structure are not well understood. Our study aimed to address this question by longitudinally tracking changes in trabecular and cortical bone microarchitecture at the proximal tibia in rats throughout three cycles of pregnancy, lactation, and post-weaning using in vivo μCT. We found that the trabecular thickness underwent a reversible deterioration during pregnancy and lactation, which was fully recovered after weaning, whereas other parameters of trabecular microarchitecture (including trabecular number, spacing, connectivity density, and structure model index) underwent a more permanent deterioration, which recovered minimally. Thus, pregnancy and lactation resulted in both transient and long-lasting alterations in trabecular microstructure. In the meantime, multiple reproductive cycles appeared to improve the robustness of cortical bone (resulting in an elevated cortical area and polar moment of inertia), as well as increase the proportion of the total load carried by the cortical bone at the proximal tibia. Taken together, changes in the cortical and trabecular compartments suggest that whereas rat tibial trabecular bone appears to be highly involved in maintaining calcium homeostasis during female reproduction, cortical bone adapts to increase its load-bearing capacity, allowing the overall mechanical function of the tibia to be maintained. © 2017 American Society for Bone and Mineral Research.

Validation of the Arabic Version of the Infant Feeding Intentions Scale Among Lebanese Women

BACKGROUND

The Infant Feeding Intentions (IFI) scale was shown to reliably measure maternal intentions to initiate breastfeeding and continue exclusive breastfeeding until 1, 3, or 6 months in English and Spanish but not in Arab contexts. Research aim: This study aimed to validate an Arabic version of the IFI scale (IFI-A) and examine its ability to predict exclusive breastfeeding at 1, 3, or 6 months in pregnant Lebanese women.

METHODS

The internal consistency reliability and construct validity of the IFI-A scale were tested on 50 pregnant women (Group 1), whereas its predictive ability was tested on 196 pregnant women (Group 2), who were surveyed monthly about their infants' nutrition method until 6 months.

RESULTS

The IFI-A scale's Cronbach's alpha internal consistency reliability is .82. Its corrected item-total correlations ranged from .26 for Item 2 ("at least give breastfeeding a try") to .86 for Item 4 ("will be exclusively breastfeeding at 3 months"). Exploratory factor analysis revealed that it is unidimensional. IFI-A scores correlated significantly with exclusive breastfeeding duration in Group 1 ( r = .624; p = .001) and with participants' breastfeeding attitude ( r = .390; p < .001) and previous breastfeeding duration ( r = .237; p = .011) in Group 2, thus confirming its external construct validity. In adjusted analysis, the IFI-A scale predicted exclusive breastfeeding at 3 months, albeit weakly (odds ratio = 1.16; 95% confidence interval [0.99, 1.36]), but not at 1 or 6 months.

CONCLUSION

The IFI-A scale is a reliable and valid tool to assess maternal feeding intentions and predict exclusive breastfeeding at 3 months in the Arab context. Further studies are needed in other Arab contexts to confirm our findings.

The Skeleton Is a Storehouse of Mineral That Is Plundered During Lactation and (Fully?) Replenished Afterwards

During lactation, mammals resorb mineral from the maternal skeleton to provide calcium to milk. Rodents lose 25% to 35% of skeletal ash weight, ash calcium content, and bone mineral content as measured by dual-energy X-ray absorptiometry (DXA), and have compromised material properties of bone as assessed by crushing vertebrae and 3-point bend tests of femora or tibias. The strength, stiffness, and toughness of vertebrae, femora, and tibias are reduced by as much as 60%. The effects of lactation are not uniform throughout the skeleton, but instead resorption is much more marked in the trabecular-rich spine than in the appendicular skeleton or whole body. Women who breastfeed exclusively lose an average of 210 mg calcium in milk each day, whereas nursing of twins or triplets can double and triple the output of calcium. Clinical data are also consistent with skeletal calcium being released during lactation to provide much of the calcium needed for milk production. Lumbar spine bone mineral density (BMD), as assessed by DXA, declines by a mean of 5% to 10% among numerous studies during 3 to 6 months of exclusive lactation, whereas largely cortical sites (hip, forearm, whole body) show half that loss or no significant changes. Micro-CT of rodents and high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging of women confirm that lactation causes microarchitectural deterioration of bone. These skeletal losses occur through two pathways: upregulated osteoclast-mediated bone resorption and osteocytic osteolysis, in which osteocytes remove mineral from their lacunae and pericanalicular spaces. After weaning, the skeleton is fully restored to its prior mineral content and strength in both animal models and humans, despite persistent microarchitectural changes observed in high-resolution imaging. Osteoblasts upregulate to lay down new osteoid, while osteocytes remineralize their surroundings. The factors that stimulate this post-weaning skeletal recovery remain unclear. In most studies, a history of lactation does not increase the risk, but may protect against, low BMD and fragility fractures. © 2017 American Society for Bone and Mineral Research.

Intention to Breastfeed as a Predictor of Initiation of Exclusive Breastfeeding in Hispanic Women

Exclusive breastfeeding (EBF) is the most efficacious form of infant feeding and nutrition. Hispanic mothers in the US are more likely than mothers of other racial/ethnic groups to supplement with formula in the first 2 days of life. The purpose of this study was to explore infant feeding intentions during the prenatal period as a predictor of EBF at postpartum discharge in a sample of Hispanic women (n = 99). At discharge, 51 % of the women were EBF, 44 % were breastfeeding and supplementing with formula, and 5 % were feeding only formula. Intention to breastfeed was found to be a strong and potentially modifiable predictor of breastfeeding behavior, showing a significant association with EBF upon discharge from the hospital after birth when linked with acceptance of pregnancy and method of delivery. Prenatal care offers a unique opportunity to enhance intentions to breastfeed that may lead to improved EBF in this health vulnerable population.

The Relationship between Prenatal Antidepressant Use and the Decision to Breastfeed among Women Enrolled in a Randomized Exercise Intervention Trial

BACKGROUND

Despite the numerous health benefits associated with breastfeeding, only 49% of postpartum women in the United States breastfeed at 6 months. Therefore, it is important to understand factors that may influence a woman's decision to breastfeed.

OBJECTIVE

The purpose of this study was to examine the relationship between prenatal antidepressant use and the decision to breastfeed among postpartum women.

METHODS

Participants were postpartum women (N = 87) who had participated in a randomized trial examining the efficacy of a 6-month exercise intervention for the prevention of postpartum depression (2009-2012). Participants were recruited from the upper Midwest and were at risk for postpartum depression. Participants completed telephone-based questionnaires assessing their prenatal antidepressant use and breastfeeding behavior.

RESULTS

Seventeen percent of the participants took an antidepressant medication during pregnancy and 91% breastfed at birth. After controlling for baseline depressive symptoms, body mass index, and condition assignment, participants who were taking an antidepressant during pregnancy were less likely to initiate breastfeeding than participants who were not taking an antidepressant during pregnancy, β = -2.042, P < .05 (odds ratio = 0.130; 95% confidence interval, 0.024-0.696).

CONCLUSION

Our study indicates that prenatal antidepressant medication use may be a potential barrier to breastfeeding initiation. Additional research is needed to better understand the factors that play a role in the relationship between prenatal antidepressant use and breastfeeding initiation.

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.

Association between prolonged breastfeeding and bone mineral density and osteoporosis in postmenopausal women: KNHANES 2010-2011

This study showed that a negative correlation between duration of breastfeeding and bone mineral density (BMD) in the lumbar spine and prolonged breastfeeding is an independent risk for osteoporosis in postmenopausal women. The present study suggests that postmenopausal women with a history of prolonged breastfeeding require more careful screening for osteoporosis.

INTRODUCTION

Several studies suggest that breastfeeding and childbirth lead to maternal calcium loss and a decline in BMD. While the association between breastfeeding and BMD immediately after weaning is well-established, the effects of breastfeeding on postmenopausal women have been controversial. The aim of this study was to examine the effects of breastfeeding on bone mineral density (BMD) and the prevalence of osteoporosis in postmenopausal women.

METHODS

The present study was a cross-sectional survey based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2010 and 2011 data. The association between breastfeeding and BMD and osteoporosis was examined in 1222 postmenopausal women.

RESULTS

The duration of breastfeeding and BMD in the lumbar spine showed a negative correlation. The association between duration of breastfeeding and BMD remained significant after adjustment for reproductive factors and other confounding factors (P = 0.008). However, the number of deliveries and age at the time of delivery did not correlate with BMD at any site after adjustment. Moreover, the prevalence of osteoporosis in postmenopausal women with a history of prolonged breastfeeding was significantly higher than that in women with a short history of breastfeeding (≥37 months, OR = 3.292; 95 % CI 1.485-7.299). The prevalence of lumbar spine fracture showed a significant increasing trend with the increase in the duration of breastfeeding.

CONCLUSION

Prolonged breastfeeding was significantly associated with low BMD in the lumbar spine and higher prevalence of osteoporosis. However, the number of deliveries or age at the time of childbirth did not influence BMD.

Breastfeeding and maternal health outcomes: a systematic review and meta-analysis

AIM

To evaluate the effect of breastfeeding on long-term (breast carcinoma, ovarian carcinoma, osteoporosis and type 2 diabetes mellitus) and short-term (lactational amenorrhoea, postpartum depression, postpartum weight change) maternal health outcomes.

METHODS

A systematic literature search was conducted in PubMed, Cochrane Library and CABI databases. Outcome estimates of odds ratios or relative risks or standardised mean differences were pooled. In cases of heterogeneity, subgroup analysis and meta-regression were explored.

RESULTS

Breastfeeding >12 months was associated with reduced risk of breast and ovarian carcinoma by 26% and 37%, respectively. No conclusive evidence of an association between breastfeeding and bone mineral density was found. Breastfeeding was associated with 32% lower risk of type 2 diabetes. Exclusive breastfeeding and predominant breastfeeding were associated with longer duration of amenorrhoea. Shorter duration of breastfeeding was associated with higher risk of postpartum depression. Evidence suggesting an association of breastfeeding with postpartum weight change was lacking.

CONCLUSION

This review supports the hypothesis that breastfeeding is protective against breast and ovarian carcinoma, and exclusive breastfeeding and predominant breastfeeding increase the duration of lactational amenorrhoea. There is evidence that breastfeeding reduces the risk of type 2 diabetes. However, an association between breastfeeding and bone mineral density or maternal depression or postpartum weight change was not evident.

Breast Feeding Is Associated with Postmenopausal Bone Loss: Findings from the Korea National Health and Nutrition Examination Survey

BACKGROUND

Postmenopausal osteoporosis is a common disease which can cause various morbidity and economic burden. Lactation is known to cause a decline in bone mineral density (BMD), but there are controversies on whether decreased BMD is fully recovered after lactation and whether lactation duration has an influence on postmenopausal BMD. This study was conducted to see whether breastfeeding is associated with postmenopausal bone loss using a highly representative sample of Korean population.

METHODS

Retrospective cross sectional study was done using data collected from Korea National Health and Nutrition Examination Survey V. The study outcome was BMD measured with dual-energy X-ray absorptiometry and divided into 2 groups: normal or low BMD (T score<-1), and breastfeeding duration was categorized into 4 groups (never, 1st, 2nd, and 3rd tertile). Logistic regression analysis was done to examine the association between lactation duration and BMD.

RESULTS

Among 1,694 postmenopausal women (mean age, 63.5±9.1), 85.71% were in low BMD group. Compared to never breastfeeding group, postmenopausal women with longer than 79 months of breastfeeding duration are more likely to have low BMD (adjusted risk ratio [ARR]=1.24; 95% confidence interval, 1.17 to 1.32). As the duration of breastfeeding increases, ARR and risk difference for low BMD also increases (P for trend=0.008).

CONCLUSION

The study results showed that total breastfeeding duration was associated with postmenopausal low BMD. All women planning on breastfeeding should be aware of its risks and should take adequate dietary calcium and vitamin D before, during, and after breastfeeding.

Non-linear pattern of age-specific bone mineral density and related factors in women: data from the 5th Korea National Health and Nutrition Examination Survey

Age-specific bone mineral density (BMD) of Korean women showed a nonlinear pattern. According to our study, this pattern could be mainly attributed to the nonlinear effects of body composition. Interventions targeting these factors in premenopausal women could be critical for achieving peak BMD.

PURPOSE

The patterns of age-specific bone mineral density (BMD) of femur and spine in women showed a non-unidirectional decrease, with ups and downs around the point of achieving peak BMD, that are not evident in men. We investigated the factors associated with these age-specific BMD in women using linear and nonlinear models.

METHODS

A total of 4681 women recruited during the 5th Korean National Health and Nutrition Examination Survey 2010-2011 (KNHANES V) were included. A range of related factors were considered including body compositional, reproductive, and socio-behavioral factors. Age-specific BMD was demonstrated using a generalized additive model (GAM) with smoothing spline transformation.

RESULTS

Age, lean body mass, fat mass, and age at menarche were significant predictors of BMD in premenopausal women. The GAM plot of BMD according to age revealed two peaks for total femur, femoral neck, and lumbar spine. After adjustment for body compositional factors, the peaks flattened. In the full model, the pattern for lumbar spine showed a single peak around the mid-40s. The GAM showed a generally better performance than the linear model for BMD at all three sites. Reduced models that included only lean body mass and fat mass best explained the variance of BMD in GAMs.

CONCLUSIONS

The BMD of Korean women in reproductive period could be largely attributed to the nonlinear effects of age and body compositional factors. Intervention targeting these factors could be critical for maintaining peak BMD.

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.

Changes in body composition in apparently healthy urban Indian women up to 3 years postpartum

INTRODUCTION

Dietary and life style practices differ in postpartum (PP) and nonpregnant Indian women. Effect of these practices on postpartum weight retention (PPWR) and development of cardio-metabolic risk (CMR) has been scarcely studied in urban women. Aims of this study were to (i) compare anthropometry, biochemical parameters and body composition up to 3 years PP (ii) effect of PPWR, dietary fat intake and physical activity on CMR factors.

DESIGN

Cross-sectional, 300-fullterm, apparently healthy primi-parous women (28.6 ± 3.4 years) randomly selected. 128 women within 7-day of delivery (Group-A), 88 with 1-2 years (Group-B) and 84 with 3-4-year-old-children (Group-C) were studied. Anthropometry, sociodemographic status, physical activity, diet, clinical examination, biochemical tests, body composition, at total body (TB), by dual energy X-ray absorptiometry (GE-Lunar DPX) were collected.

RESULTS

Women at 3-year PP showed higher weight retention (6.5[10] kg) than at 1-year (3.0[7] kg) (median [IQR]). Android fat % (central obesity) increased (P < 0.05) at 1-year PP (47 ± 10.0%) when compared to 1-week PP (44.3 ± 6.7%) and remained elevated at 3-year PP (45.6 ± 10.2%). Regression analysis revealed that at 1-year PP, increase in PPWR (Odd Ratio [OR] 1.8, 95% confidence interval [CI] = [1.2, 2.5], P < 0.001) and inactivity (OR 1.4, 95% CI= (0.97, 2.0), P < 0.1) were predictors for CMR. At 3-year PP, only PPWR was responsible for increase in CMR parameters (OR 1.6, 95% CI = (1.3, 2.3), P < 0.001) and not inactivity (P > 0.1).

CONCLUSION

Postdelivery, low physical activity and higher PPWR may increase CMR in Indian women.

Parity, lactation, bone strength, and 16-year fracture risk in adult women: findings from the Study of Women's Health Across the Nation (SWAN)

Our objective was to examine the associations of lifetime parity and accumulated length of lactation with bone strength in women prior to the menopause transition and fracture risk during and after the transition. Participants were 2239 pre- or early peri-menopausal women from the Study of Women's Health Across the Nation (SWAN), ages 42-53 years at baseline, who had no childbirths after age 42. Bone mineral density (BMD) was measured in the femoral neck and the lumbar spine at the baseline SWAN visit using dual-energy x-ray absorptiometry, and the composite indices of femoral neck strength relative to load (in three failure modes: compression, bending, and impact) were calculated from femoral neck BMD, femoral neck size, and body size. Data on fractures after age 42 were collected for a median follow-up of 15.7 years (interquartile range, 11.4-18.5 years). In multiple linear regressions adjusted for covariates, lifetime parity was associated positively with femoral neck strength relative to load (0.024 standard deviation (SD) increment in impact strength index per childbirth, p=0.049), but accumulated length of lactation was associated negatively with lumbar spine BMD (0.018 SD decrement per every additional 6 months of lactation, p=0.040). In Cox proportional hazards regressions adjusted for covariates, neither parity nor lactation was associated with fracture hazard after age 42. In conclusion, parity and lactation have little impact on peak bone strength prior to menopause, and do not affect fracture risk after age 42 over 16-year follow-up.

Changes in cortical volumetric bone mineral density and thickness, and trabecular thickness in lactating women postpartum

CONTEXT

Lactation is associated with decreased areal bone mineral density (aBMD). Replenishment occurs especially after ceased lactation. Changes in volumetric bone mineral density (vBMD), microstructure, and dimensional parameters are unknown and may clarify the role of lactation for skeletal health. OBJECTIVE AND MAIN OUTCOMES: The objective of the study was to test the hypothesis that lactation is associated with changes in aBMD, vBMD, microstructure, and dimensional parameters.

DESIGN

At baseline (0.5 mo after delivery) and 4, 12, and 18 months thereafter, bone was assessed using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography.

PARTICIPANTS AND SETTING

Eighty-one fair-skinned postpartum women and 21 controls aged 25-40 years were recruited. The completion ratio was 73%. Postpartum women were categorized depending on duration of lactation: 0-3.9, 4-8.9, and 9 months or longer.

RESULTS

During the first 4 months, aBMD decreased at several sites (geometric mean ± SE; -0.73% ± 0.21% to -3.98% ± 0.76%) in women lactating at least 4 months. During the same time, cortical vBMD at the ultradistal tibia decreased in women lactating 4-8.9 months (-0.26% ± 0.08%) and 9 months or longer (-0.49% ± 0.10%). At 12 months postpartum, cortical thickness (≥ 9 mo, -2.48% ± 0.41%) and trabecular thickness (4-8.9 mo, -2.14% ± 0.92%; ≥ 9 mo, -2.56% ± 1.21%) also were lower than baseline. No decreases were found in women lactating less than 4 months or in controls in these parameters. At 18 months postpartum, both cortical vBMD (≥ 9 mo, -0.77% ± 0.17%) and trabecular thickness (4-8.9 mo, -2.25% ± 1.25%; ≥ 9 mo, -3.21% ± 1.41%) were lower in women with long lactation.

CONCLUSIONS

Decreases in cortical vBMD, thickness, and trabecular thickness at the ultradistal tibia were found in women lactating 4 months or longer. Longer follow-up is needed to confirm whether women with extended lactation recover fully or whether the changes could potentially lead to an increased risk of fracture in later life.

Osteoporosis presenting in pregnancy, puerperium, and lactation

PURPOSE OF REVIEW

To describe our current state of knowledge about the pathophysiology, incidence, and treatment of osteoporosis that presents during pregnancy, puerperium, and lactation.

RECENT FINDINGS

When vertebral fractures occur in pregnant or lactating women, it is usually unknown whether the skeleton was normal before pregnancy. Maternal adaptations increase bone resorption modestly during pregnancy but markedly during lactation. The net bone loss may occasionally precipitate fractures, especially in women who have underlying low bone mass or skeletal fragility prior to pregnancy. Bone mass and strength are normally restored postweaning. Transient osteoporosis of the hip is a sporadic disorder localized to one or both femoral heads; it is not due to generalized skeletal resorption. Anecdotal reports have used bisphosphonates, strontium ranelate, teriparatide, or vertebroplasty/kyphoplasty to treat postpartum vertebral fractures, but it is unclear whether these therapies had any added benefit over the spontaneous skeletal recovery that normally occurs after weaning.

SUMMARY

These relatively rare fragility fractures result from multifactorial causes, including skeletal disorders that precede pregnancy, and structural and metabolic stresses that can compromise skeletal strength during pregnancy and lactation. Further study is needed to determine when pharmacological or surgical therapy is warranted instead of conservative or expectant management.

Duration of breastfeeding as a risk factor for vertebral fractures

PURPOSE

Among the risk factors for osteoporosis and fractures, gynecological history (fertile period, parity and breastfeeding) play an important part. Changes in calcium metabolism to enable an adequate mineral transfer to the milk have a prominent role in bone loss during breastfeeding. Data on the influence of breastfeeding in postmenopausal osteoporosis are inconsistent. The aim of the present study was to identify any association between duration of breastfeeding and vertebral fractures in postmenopausal women.

METHODS

All patients underwent the following tests: bone mineral density measurements of the lumbar spine (L1-L4) and the total and femoral neck using dual-energy X-ray absorptiometry and antero-posterior and lateral radiography of the thoracic and lumbar spine to identify vertebral fractures.

RESULTS

The study involved 752 women with a mean age of 64.5±9.3; 23% of them reported vertebral osteoporotic fractures. The women with vertebral fractures had breastfed for longer periods (11.8±12.9 vs. 9.3±11.2months, p=0.03) and had more pregnancies (2.6±2.2 vs. 2.2±1.3, p=0.002). Breastfeeding for more than 18months was associated with a two-fold risk of developing vertebral fractures (OR 2.12, 95% CI 1.14-5.38, p=0.04), particularly in those without current or past use of drugs positively affecting bone.

CONCLUSIONS

Our study showed an association between long periods of breastfeeding and vertebral fractures, supporting a role for lengthy lactation as a risk factor for osteoporotic fractures after menopause. Bearing in mind all the benefits of breastfeeding, this finding suggests the importance of an adequate calcium and vitamin D intake during pregnancy and breastfeeding, with the aid of dietary supplements if necessary.

Bone mineral density in gravida: effect of pregnancies and breast-feeding in women of differing ages and parity

Changes of bone during pregnancy and during lactation evaluated by bone mineral density (BMD) may have implications for risk of osteoporosis and fractures. We studied BMD in women of differing ages, parity, and lactation histories immediately postpartum for BMD, T-scores, and Z-scores. Institutional Review Board approval was received. All women while still in hospital postpartum were asked to participate. BMD was performed by dual-energy X-ray absorptiometry (DXA) machine at femoral neck (FN) and lumbar spine (LS) by a single technician. Of 132 participants, 73 (55.3%) were ≤30 years; 27 (20.5%) were primiparous; 36 (27.3%) were grand multiparous; 35 (26.5%) never breast fed. Mean FN T-scores and Z-scores were higher than respective mean LS scores, but all means were within the normal limits. Mean LS T-scores and Z-scores were highest in the grand multiparas. There were only 2 (1.5%) outliers with low Z-scores. We conclude that, in a large cohort of Israeli women with BMD parameters assessed by DXA within two days postpartum, mean T-scores and Z-scores at both the LS and FN were within normal limits regardless of age (20-46 years), parity (1-13 viable births), and history of either no or prolonged months of lactation (up to 11.25 years).

Increased bone mineral density is associated with breastfeeding history in premenopausal Spanish women

INTRODUCTION

During lactation abundant calcium is lost from the mother as a result of the amount of breast milk produced. Lactation leads to transient fragility, with some women experiencing even fragility fractures, but nearly all of these women subsequently undergo a large increase in bone mineral density (BMD), confirming that the BMD must have declined during lactation but it increases after weaning. We have retrospectively examined the relationship between the duration of breastfeeding and bone properties in Spanish premenopausal healthy women, to identify the site-specific changes in BMD.

MATERIAL AND METHODS

Four hundred and thirty-three premenopausal healthy women, 295 with a mean of 7.82 ±6.68 months of exclusive breastfeeding and 138 control women, were studied. We examined total, trabecular and cortical volumetric BMD (mg/mm(3)) at the distal radius using peripheral quantitative computed tomography. Areal BMD (g/cm(2)) was measured using dual energy X-ray absorptiometry at the femoral neck, lumbar spine, trochanter and Ward's triangle. Phalangeal bone ultrasound was measured by amplitude-dependent speed of sound.

RESULTS

Areal BMD analysis at L2-L4 revealed significant intergroup differences (p < 0.05). There were significant intergroup differences in the volumetric BMD in both total and cortical bone (p < 0.05). The observed BMD of breast-feeders was higher than the BMD in non-breast-feeding women. Additionally, the lactation subgroup analysis revealed significant differences in the areal BMD at trochanter and L2-L4 (p < 0.05) and in the cortical volumetric BMD (p < 0.05).

CONCLUSIONS

This study adds to the growing evidence that breastfeeding has no deleterious effects and may confer an additional advantage for BMD in premenopausal women.