Adolescent Caucasian mothers have reduced adult hip bone density

Does adolescent pregnancy affect postmenopausal bone mineral density?

Aim: This study aims to investigate the effect of adolescent pregnancies on bone mineral density in the postmenopausal period and to contribute to this controversial issue. Material and Method: Our study included 70 women at postmenopausal ages. The participants were divided into two groups. Thirty-five women with a history of pregnancy in adolescence were considered group 1, and 35 women without a history of pregnancy were considered group 2. The BMD was measured in the total hip, femoral neck, and lumbar spine. The data were compared using SPSS version 26, and p

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.

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.

Adolescent pregnancy; a determinant of bone mineral density in peri-menopausal women?

OBJECTIVE

The present study aims to determine the effects of a history of adolescent pregnancy (AP) on the bone mineral density (BMD) of perimenopausal women.

METHODS

Overall, 240 women aged between 40 and 55 years, with a complaint of oligomenorrhea or amenorrhea not exceeding 1 year in duration, were evaluated. Evaluation included a DEXA scan and a detailed demographic survey for bone health. Comparison was made between women with a history of AP and those without.

RESULTS

In total, 87 women who had a history of AP were compared with 153 women who did not have a history of AP. The study groups did not differ significantly for most of the evaluated demographic factors. Women with a history of AP had higher gravidity and parity. Comparison of T-scores revealed lumbar BMD to be unaffected by AP (P=0.184), whereas femoral BMD was positively influenced by a history of AP (0.78±0.65 vs -1.06±0.67; P=0.042). In covariance regression models, after adjusting for parity and age of first menarche, AP still positively influenced femoral BMD. Without a history of AP, women were at increased risk for osteoporosis of femoral neck (odds ratio, 2.8, 95% CI 1.75-4.8).

CONCLUSIONS

The effects of AP on BMD are not well elucidated. Women with a history of AP had better femoral BMD scores, indicating a possible protective influence of AP on bone health.

BRIEF SUMMARY

Pregnancy during adolescence is associated with a better femoral bone mineral density than pregnancy at an older age. However, the effects did not extend to lumbar spine bone mineral density.

Adolescent pregnancy is associated with osteoporosis in postmenopausal women

OBJECTIVE

Adolescence is a critical time of life to accumulate bone for peak bone mass. Factors that may interfere with bone mass accrual during this period may increase the risk of osteoporosis. Several studies have reported that pregnancy during adolescence has detrimental effects on bone mass measurements after pregnancy. However, less is known about how adolescent pregnancy affects bone mineral density (BMD) and osteoporosis after menopause. The aim of this study was to evaluate the association between adolescent pregnancy and osteoporosis in postmenopausal Korean women.

METHODS

We conducted a cross-sectional study of 719 postmenopausal women, all of whom were enrolled in the Korean National Health and Nutrition Examination Survey in 2008. BMD was measured using dual-energy x-ray absorptiometry.

RESULTS

Postmenopausal women with histories of adolescent pregnancy had lower BMD of the total hip, femoral neck, and lumbar spine than did women without histories of adolescent pregnancy. Multivariate logistic regression analyses revealed that postmenopausal women with history of adolescent pregnancy were at increased risk of osteoporosis (odds ratio, 2.20; 95% CI, 1.12-4.30) compared with women without history of adolescent pregnancy after adjustments for age, body mass index, marital status, education level, household income, alcohol intake, smoking history, exercise, age at menarche, age at menopause, parity, hormone therapy use, intake of energy and calcium, and vitamin D level.

CONCLUSIONS

Adolescent pregnancy may be a predictor of osteoporosis in postmenopausal women.

Postpartum bone status in teenage mothers assessed using peripheral quantitative computed tomography

Teenage pregnancy occurs during a time when the maternal skeleton may still be accruing mineral. We hypothesized that teenage mothers would have reduced amounts of bone mineral and altered bone geometry compared with controls. This cross-sectional, observational compared teenage mothers (n=18) to age- and ethnicity-matched controls (n=52). The main outcomes were peripheral quantitative computed tomography and dual-energy X-ray absorptiometry to measure bone geometry, bone mineral density (BMD) at radius, lumbar spine and hip, and whole body bone mineral content (WBBMC). In teenage mothers, cortical BMD was reduced at the radial diaphysis (mean difference: -1.3%; p=0.03). Size-adjusted WBBMC was reduced (mean difference: -4.0%; p=0.004) and was lower for a given amount of lean mass (mean difference: -5.8%; p=0.02). No other significant differences between groups were found. The recruitment and retention of participants to this study were extremely difficult and disappointing. Teenage mothers had lower BMD at cortical sites compared with age-matched controls. These data suggest that pregnancy might have a detrimental effect on teenage mothers' future skeletal health. The results of this study require confirmation and provide pilot data for further investigations.

Bone mass and breast milk calcium concentration are associated with vitamin D receptor gene polymorphisms in adolescent mothers

Lactation-associated bone loss has been reported in adolescent mothers. Polymorphisms in the vitamin D receptor (VDR) gene may contribute to differences in the physiologic skeletal response to lactation in these mothers. We evaluated the influence of VDR gene polymorphisms ApaI, BsmI, and TaqI on bone mass, bone and calcium-related hormones, and breast milk calcium of lactating adolescents with habitually low calcium intake. Total body bone mineral content (TBMC), total body bone mineral density (TBMD), lumbar spine BMD (LSBMD), serum hormones [intact parathyroid hormone (iPTH), 25-hydroxyvitamin D, insulin-like growth factor-I (IGF1), prolactin, and estradiol), and breast milk calcium were measured in 40 lactating Brazilian adolescents (15-18 y), and compared by VDR genotype subgroups after adjustment for calcium intake and postmenarcheal and lactational periods. TBMD and LSBMD Z scores were -0.55 +/- 1.01 and -1.15 +/- 1.48, respectively. LSBMD was higher (21%; P < 0.05) in adolescents with the aa genotype (n = 5) compared with those with the AA genotype (n = 7). TBMC and IGF1 were higher (23 and 50%, respectively; P < 0.05) in adolescents with tt (n = 4) than those with TT (n = 29) and Tt (n = 7) genotypes. Breast milk calcium and serum iPTH were higher (24 and 80%, respectively; P < 0.05) in adolescents with bb (n = 8) compared with those with BB (n = 21) genotype. These results indicate that bone mass and breast milk calcium are significantly associated with VDR genotypes in lactating Brazilian adolescents. Those with aa and tt genotypes had a better bone status and those with bb genotype had greater breast milk calcium.

The association of pregnancy history with areal and volumetric bone mineral density in adolescence

INTRODUCTION

Studies demonstrate that pregnancy may interfere with bone mineral density. Adolescence is a crucial time of life for bone mass acquisition and there are some questions as to the influence of pregnancy on bone mass at this age.

OBJECTIVE

To evaluate the association between pregnancy history and areal (BMD) and volumetric (vBMD) bone mineral density in adolescence.

SUBJECTS AND METHODS

A cross-sectional study of 119 adolescents ranging from 12-20 years of age was conducted; 30 of these girls had a history of full-term pregnancy. The adolescents were selected during a routine visit to the Adolescent Gynecology Outpatient Facility, completed a questionnaire, and had a physical examination to evaluate weight, height and Tanner stage. Bone mineral densitometry of the lumbar spine (L(1)-L(4)) and total body (TB) was performed to measure bone mineral density and body composition.

RESULTS

The mean measurements of the area, bone mineral content (BMC), BMD and vBMD of L(1)-L(4) and the area, BMC and BMD of TB were not significantly different between adolescents with and without a pregnancy history, stratified by chronologic and gynecologic age. The percentage of adolescents with altered Z-scores was similar in both groups, and the prevalence ratio showed no association between pregnancy history and low bone mass (PR=0.52; CI 0.04-6.07). Upon multiple regression analysis, body mass index (BMI) and lean body mass (LBM) were the main factors associated with lumbar spine and total body measurements. Pregnancy history was inversely associated with areal BMD of L(1)-L(4) (R (2)=0.04) and vBMD of L(1)-L(4) (R (2)=0.04), accounting for only 4% variation in the lumbar spine.

CONCLUSION

These data suggest that adolescent pregnancy seems to exert no significant influence on the acquisition of bone mass and does not appear to represent a risk factor for osteoporosis in the future.

Bone status during adolescence, pregnancy and lactation

PURPOSE OF REVIEW

At birth, the fetus will contain 30 g of calcium; during the third trimester the calcium accrual can be up to 340 mg/day. Therefore, extremely high demands for calcium provision are placed upon the mother. This review aims to describe the adaptive mechanisms of the female skeleton to pregnancy and lactation, which ensure optimal fetal skeletal mineralization without compromise to maternal bone strength.

RECENT FINDINGS

Descriptions of changes in bone status during pregnancy and lactation have been published. One of the only studies to measure pre-conception to post-weaning shows complete recovery of maternal spinal bone mineral density (BMD) and near recovery at the hip. Most studies describe trabecular bone loss, but there is evidence for endosteal resorption of the metacarpals. In a retrospective study of former teenage mothers those who breastfed had similar hip BMD to nulliparous age-matched women; those who did not breastfeed had lower hip BMD. Maternal response to low calcium intake differs from that of normal calcium intake.

SUMMARY

Pregnancy and lactation do not have an overall negative effect upon the maternal skeleton. Retrospective evidence suggests no harmful effect of teenage pregnancy if the teenager breastfed, but this requires further investigation. The effects of other situations, for example low vitamin D status or low calcium intake, require further research to inform future clinical practice.

Lifestyle factors and the development of bone mass and bone strength in young women

OBJECTIVE

To evaluate the contributions of adolescent calcium intake, oral contraceptive use, and exercise on bone mass and bone strength.Study design Eighty white women participated in 10 years of the Penn State Young Women's Health Study, a longitudinal study of community participants. We measured bone mineral mass (g), density (BMD, g/cm(2)), and body composition from dual energy x-ray absorptiometry and estimated proximal femur section modulus (bone bending strength). Calcium intake was determined from 45 days of prospective food records at regular intervals between the ages of 12 and 22 years. Exercise history and oral contraceptive use were assessed by questionnaire.

RESULTS

Daily calcium intakes between the ages of 12 and 22 years ranged from 500 to 1900 mg/d and were not significantly associated with bone gain or bone strength. Oral contraceptive use during adolescence was not correlated with bone or body composition measurements. Femoral neck BMD did not change from 17 to 22 years of age, but section modulus increased 3% (P <.05). Only exercise during adolescence was significantly associated with increased BMD and bone bending strength.

CONCLUSIONS

Adolescent lifestyle patterns can influence young adult bone strength. Our data suggest that exercise is the predominant lifestyle determinant of bone strength for this cohort.

Calcium absorption is significantly higher in adolescents during pregnancy than in the early postpartum period

BACKGROUND

Early childbearing may limit skeletal consolidation and increase calcium demands in adolescents.

OBJECTIVE

The purpose of this study was to characterize calcium absorption in pregnant and lactating adolescents.

DESIGN

Fractional calcium absorption was evaluated in 23 adolescents (mean +/- SD age: 16.5 +/- 1.4 y) during the third trimester of pregnancy (34.7 +/- 1.0 wk gestation) and again in 15 of these adolescents 31 +/- 8 d after delivery. Eight adolescents were breastfeeding their infants during the follow-up study. Fractional calcium absorption was determined by using oral ((46)Ca or (44)Ca) and intravenous ((42)Ca) stable calcium isotopes. Total-body and lumbar spine bone mineral density were measured in adolescents during the postpartum period by using dual-energy X-ray absorptiometry.

RESULTS

Fractional calcium absorption was significantly greater during pregnancy than at 3-4 wk postpartum [0.526 +/- 0.152 (n = 23) compared with 0.297 +/- 0.108 (n = 15); P < 0.0001]. Lumbar spine z scores measured 19-44 d after delivery (n = 15) were significantly associated with calcium intake during pregnancy (y = -3.53 + 0.107x; R(2) = 0.355, P < 0.02) and were inversely related to fractional calcium absorption during pregnancy (y = 3.489 - 6.66x; R(2) = 0.52, P = 0.002). A total of 33% (5/15) of adolescents had lumbar spine z scores that met the definition of osteopenia (n = 3) or osteoporosis (n = 2) in the early postpartum period.

CONCLUSIONS

Calcium absorption in adolescents was significantly higher during the third trimester of pregnancy than in the early postpartum period, and higher calcium intakes during pregnancy appeared to be protective against loss of trabecular bone at the lumbar spine.

The impact of reproductive and menstrual history on bone mineral density in Chinese women

Low bone mineral density (BMD) is an important risk factor for osteoporotic fractures. The impact of gynecological history on BMD is of great concern, but the results are largely inconsistent. In this study, we investigated the association of gynecological history with BMD in 214 postmenopausal women (60.4 +/- 5.7 yr), as well as with peak bone density (PBD) in 428 premenopausal women (30.8 +/- 5.3 yr) from Shanghai City in China. BMD was measured at lumbar spine (L1-4) and total hip by dual energy X-ray absorptiometry. Raw BMD values were adjusted by age, age2, height, and weight. In the postmenopausal group, more parity had significantly detrimental effects on BMD at both the spine and hip (p < 0.01). The age of the first delivery, the duration of lactation, and the age at menarche did not show significant impacts on BMD (p > 0.05). More years since menopause only had marginally significant decreasing effects at the spine (p = 0.09), but not at the hip (p > 0.10). In the premenopausal group, none of the three reproductive factors had significant impact on PBD (p > 0.05); the age of menarche inversely affected PBD at both the spine (p < 0.01) and hip (p < 0.05). Our results suggest that some gynecological events might influence BMD variation in healthy Chinese women.