Maternal vitamin D and offspring trabecular bone score

Early Life Programming of Skeletal Health

PURPOSE OF REVIEW

Increasing bone mineral accrual during childhood might delay the onset of osteoporosis. We discuss the scientific evidence for early life approaches to optimising skeletal health.

RECENT FINDINGS

There is an ever-growing body of evidence from observational studies suggesting associations between early life exposures, particularly during foetal development, and bone mineral density (BMD). The findings of such studies are often heterogeneous, and for some exposures, for example, maternal smoking and alcohol intake in pregnancy or age at conception, intervention studies are not feasible. The most frequently studied exposures in intervention studies are calcium or vitamin D supplementation in pregnancy, which overall suggest positive effects on offspring childhood BMD. Maternal calcium and/or vitamin D supplementation during pregnancy appear to have positive effects on offspring BMD during early childhood, but further long-term follow-up is required to demonstrate persistence of the effect into later life.

It starts from the womb: maximizing bone health

The foundation of bone health is established in utero. Bone accrual starts from the developing fetus and continues throughout childhood and adolescence. This process is crucial to achieve peak bone mass. Understanding factors that influence bone accrual before attainment of peak bone mass is thus critical to improve bone health and prevent osteoporosis, thereby reducing the burden of osteoporotic fractures in older women. In this review, we broadly outline factors influencing peak bone mass from pregnancy to infancy, childhood and adolescence with potential diseases and medications that may affect the optimum trajectory to maximizing bone health. It is estimated that a 10% increase in peak bone mass will delay the onset of osteoporosis by 13 years in a woman.

Gestational Vitamin D and Offspring Bone Measures: Is the Association Independent of Maternal Bone Quality?

Previously we have reported an association between maternal vitamin D and offspring bone as measured by dual-energy X-ray absorptiometry. It is plausible that shared genetics might confound associations between maternal vitamin D in pregnancy and offspring bone measures. We aimed to determine whether such associations are independent of maternal bone quality. Data for this analysis were derived from 168 mother-child pairs who returned at the 11-year follow-up of the vitamin D in pregnancy study. Gestational 25-hydroxyvitamin D [25(OH)D] was assessed by radioimmunoassay in early pregnancy at recruitment (before 16 weeks gestation) and later in pregnancy (28-32 weeks gestation). Bone quality was assessed for mothers and children at the calcaneus using quantitative ultrasound (Achilles InSight, GE). Speed of Sound (SOS), Broadband Ultrasound Attenuation (BUA) and Stiffness Index (SI) were the outcomes of interest. Maternal 25(OH)D in early pregnancy was associated with offspring SOS (β 1.46 m/s 95% CI 0.12, 2.8). When separated by sex, there was no association between maternal 25(OH)D at recruitment and offspring SI (r =  - 0.05, p = 0.68), SOS (r = 0.11, p = 0.34) or BUA (- 0.09, p = 0.43) in girls. In boys, maternal 25(OH)D at recruitment was associated with SI (r = 0.21, p = 0.048), and SOS (r = 0.24, p = 0.03) but not BUA (r = 0.10, p = 0.37). Adjustment for the offspring factors and respective maternal QUS parameter did not attenuate associations between maternal 25(OH)D in early pregnancy with offspring SOS, nor SI. There was no association with BUA. Furthermore, there was no association between maternal 25(OH)D in late pregnancy with any offspring QUS parameter. These prospective data support existing evidence of a positive relationship between maternal 25(OH)D levels during early pregnancy and measures of bone health of offspring in childhood, independent of maternal bone phenotype.

Physical and lifestyle factors associated with trabecular bone score values

TBS is associated with age, weight, childhood physical activity, and BMD in men and age, height, BMD, and mobility in women.

INTRODUCTION

Trabecular bone score (TBS) indirectly assesses trabecular microarchitecture at the lumbar spine, providing complementary information to areal BMD. Many studies have investigated the relationships between BMD and lifestyle factors known to affect bone, but such research is limited for TBS. The aim of this study was to assess the relationship between TBS and lifestyle factors in Australian men and women.

METHODS

This cross-sectional study involved 894 men and 682 women (ages 24-98 years) enrolled in the Geelong Osteoporosis Study. TBS was assessed by analysis of lumbar spine DXA scans (Lunar Prodigy) using TBS iNsight software (Version 2.2). Bivariate and multivariable linear regression models were used to explore the associations between TBS and physical and lifestyle factors, including anthropometry, alcohol consumption, childhood physical activity, mobility, smoking status, prior low trauma fracture, medication use, and intakes of calcium and vitamin D.

RESULTS

In bivariate regression modelling, low mobility and the use of antiresorptive medication were associated with lower TBS in both men and women. Low childhood physical activity was also associated with lower TBS in men. Prior fracture, use of glucocorticosteroids, and total calcium intake were also associated with lower TBS in women. The final adjusted model for men included age, weight, childhood physical activity, and BMD, and for women, age, height, BMD, and mobility. No interaction terms were identified in the models.

CONCLUSIONS

Lower TBS is associated with older age, increased weight, low childhood physical activity, and lower BMD in men and older age, shorter stature, lower BMD, and low mobility in women.

Bone Microarchitecture Assessed by Trabecular Bone Score Is Independent of Mobility Level or Height in Pediatric Patients with Cerebral Palsy

Bone strength and fracture risk do not only depend on bone density, but also on bone structure. The trabecular bone score (TBS) evaluates homogeneity of bone microarchitecture indirectly by measuring gray-level variations of two-dimensional (2D) DXA images. Although TBS is well-established for adults, there have been only few publications in pediatrics. In this monocentric retrospective analysis, we investigated TBS in children and adolescents with cerebral palsy (CP), a patient group vulnerable to low bone mineral mass due to impaired mobility. The influence of different parameters on TBS and areal BMD (aBMD) were evaluated, as well as the relationship between TBS and aBMD. We compared TBS values of our study population to a reference population. A total of 472 lumbar spine-dual-energy X-ray absorptiometry (LS-DXA) scans of children and adolescents with CP (205 female), aged between 4 and 18 years, were analyzed. The DXA-scans were part of the routine examination. The children had no records of fractures or specific bone diseases. Our study population with CP had similar TBS as the reference population. TBS did not increase with age until an inflection point at 10 years in females, and 12 years in males. Girls had significantly higher TBS than boys (p = .049) and pubertal girls aged 8 to 13 years had significantly higher TBS than prepubertal girls (p = .009). TBS standard deviation score for age (SDS-TBS) and aBMD Z-scores correlated weakly (p < .001; R = 0.276 [males], R = 0.284 [females]). Other than for aBMD Z-scores, SDS-TBS was not influenced by age-adjusted height Z-scores and there was no significant difference in SDS-TBS when grouped by mobility levels, using the Gross Motor Function Classification System (GMFCS). Our results indicate that children with CP have a similar homogeneous distribution of trabecular microarchitecture as controls. Puberty initiation appears to be essential for increase of TBS with age and for sex differences. TBS seems less influenced by body composition, height, and mobility than aBMD. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

The Vitamin D in Pregnancy Study: a prospective prebirth cohort in southern Australia

PURPOSE

The Vitamin D in Pregnancy Study is a long-term ongoing cohort study. It was conceived to explore relationships between maternal vitamin D status in pregnancy and offspring growth and development, and has since diversified to include a wide range of physical and mental health exposures and outcomes.

PARTICIPANTS

Recruitment was from the University Hospital Geelong (Barwon Health) antenatal clinic, Geelong, Victoria, Australia, between 2002 and 2004. 475 women were initially recruited, which resulted in 400 eligible mother-child pairs at birth.

FINDINGS TO DATE

The cohort has been followed up twice in pregnancy, at birth, and 1 year, 6 years and 11 years post birth. The study has reported an association between vitamin D in pregnancy and musculoskeletal health and body composition in the children.

FUTURE PLANS

Subject to funding, there will be a prospective young adult follow-up. This profile aims to foster both cross-national and international collaborations with both existing and future data collection.

Maternal serum retinol, 25(OH)D and 1,25(OH)2D concentrations during pregnancy and peak bone mass and trabecular bone score in adult offspring at 26-year follow-up

Background

Vitamin A and D deficiency is prevalent in pregnant women worldwide. Both vitamins are involved in fetal skeletal development. A positive association between maternal vitamin D levels and offspring bone mineral density (BMD) at adulthood has been observed. The impact of maternal vitamin A status in pregnancy on offspring peak bone mass remains unclear.

Method and findings

Forty-one mother-child pairs were recruited from a population-based prospective cohort study in Trondheim, Norway, where pregnant women were followed from gestational week 17. Their term-born infants were followed from birth (1986–88). Regression analyses were performed for vitamin A (retinol), 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)₂D] in maternal serum (gestational weeks 17, 33, 37) and cord blood. Offspring BMD and spine trabecular bone score (TBS), a measure of bone quality, were analyzed by dual x-ray absorptiometry at 26 years. Average levels during pregnancy of retinol, 25(OH)D and 1,25(OH)₂D were 1.66 (0.32) μmol/L, 59.0 (20.6) nmol/L, and 251.3 (62.4) pmol/L, respectively. 1,25(OH)₂D levels were similar in those with 25(OH)D levels <30 and >75 nmol/L. After adjustment for maternal age, BMI, smoking, and education, and offspring birth weight, maternal serum retinol was positively associated with offspring spine BMD [mean change 30.8 (CI 7.6, 54.0) mg/cm² per 0.2 μmol/L retinol], and with offspring TBS, although non-significant (p = 0.08). No associations were found between maternal 25(OH)D and 1,25(OH)₂D levels and offspring bone parameters. Vitamin levels in cord blood were not associated with offspring BMD or TBS.

Conclusions

This is the first study to show an association between maternal vitamin A status and offspring peak bone mass. Our findings may imply increase future risk for osteoporotic fracture in offspring of mothers with suboptimal vitamin A level. No associations were observed between 25(OH)D and 1,25(OH)₂D and offspring BMD.

Vitamin D and Trabecular Bone Score in a Group of Young Lebanese Adults

The relationship between vitamin D and trabecular bone score (TBS) in young adults remains unclear. The aim of this study was to explore the relationship between 25-hydroxyvitamin D [25(OH)D] serum levels and TBS in a healthy adult population. A total of 54 men and 61 women whose ages range from 18 to 35 participated in the present study. Participants with 25(OH)D insufficiency (between 21 and 29 ng/mL) were 55.7%, and those with 25(OH)D deficiency (≤20 ng/mL) were 11.4%. TBS positively correlated with 25(OH)D in men (r = 0.393; p <0.05) and women (r = 0.324; p < 0.05). In both genders, TBS was significantly higher in 25(OH)D-sufficient participants (≥30 ng/mL). The present study provides evidence that vitamin D positively affects bone health and suggests that maintaining adequate vitamin D status may be essential for optimal TBS values.