Birth weight predicts bone size in young adulthood at cortical sites in men and trabecular sites in women from The Gambia

Appendicular Muscle Mass Index as the Most Important Determinant of Bone Mineral Content and Density in Small for Gestational Age Children

Preterm small for gestational age (SGA) children are at increased risk for low bone mineral content later in life; however, data on SGA children born at term are scarce. We included 44 SGA and 57 adequate for gestational age (AGA) children aged 6 to 11 years to compare bone mineral density (BMD) and bone mineral content (BMC) and to identify which anthropometric and biochemical values influence bone mineralization in these children. Fat mass, appendicular skeletal muscle mass index (ASMMI), BMC, and BMD were significantly lower in SGA children than in AGA (P ≤ .005). Appendicular muscle mass index correlated with BMC(TBLH,FN,L1-L4) and BMD(TBLH,FN,L1-L4) in both groups (r2 = 0.7, P < .05). In multivariate analysis, ASMMI was strongly associated with BMC and BMD in both groups. There were no differences in clinical biomarkers, calcium intake, and physical activity between the groups. Achieving adequate muscle mass contributes to adequate bone mineralization and a lower risk for low BMC and BMD in SGA children.

Identification of PDXDC1 as a novel pleiotropic susceptibility locus shared between lumbar spine bone mineral density and birth weight

An increasing number of epidemiological studies have suggested that birth weight (BW) may be a determinant of bone health later in life, although the underlying genetic mechanism remains unclear. Here, we applied a pleiotropic conditional false discovery rate (cFDR) approach to the genome-wide association study (GWAS) summary statistics for lumbar spine bone mineral density (LS BMD) and BW, aiming to identify novel susceptibility variants shared between these two traits. We detected 5 novel potential pleiotropic loci which are located at or near 7 different genes (NTAN1, PDXDC1, CACNA1G, JAG1, FAT1P1, CCDC170, ESR1), among which PDXDC1 and FAT1P1 have not previously been linked to these phenotypes. To partially validate the findings, we demonstrated that the expression of PDXDC1 was dramatically reduced in ovariectomized (OVX) mice in comparison with sham-operated (SHAM) mice in both the growth plate and trabecula bone. Furthermore, immunohistochemistry assay with serial sections showed that both osteoclasts and osteoblasts express PDXDC1, supporting its potential role in bone metabolism. In conclusion, our study provides insights into some shared genetic mechanisms for BMD and BW as well as a novel potential therapeutic target for the prevention of OP in the early stages of the disease development. KEY MESSAGES : We investigated pleiotropy-informed enrichment between LS BMD and BW. We identified genetic variants related to both LS BMD and BW by utilizing a cFDR approach. PDXDC1 is a novel pleiotropic gene which may be related to both LS BMD and BW. Elevated expression of PDXDC1 is related to higher BMD and lower ratio n-6/n-3 PUFA indicating a bone protective effect of PDXDC1.

Bone Turnover Markers and Bone Histomorphometry in Pubertal Rats with Intrauterine Growth Restriction

To investigate the effect of malnutrition during pregnancy on bone development in rat pups with intrauterine growth restriction (IUGR). Methods: IUGR offspring were induced with a 10% low protein diet, while the control group was given a 21% protein diet during pregnancy. Serum biomarkers including bone glutamyl protein (BGP), amino-terminal propeptide of type 1 procollagen (P1NP), cross linked N-telopeptide of type I collagen (NTX), and insulin like growth factor 1 (IGF-1) levels were measured at 7, 21 and 56 d. Left femurs taken at 56 d were used for bone histomorphometry analysis by micro-computed tomography (micro-CT). Results: Compared with the control group, the IUGR group had lower IGF-1 and BGP levels at 7 and 21 d, and higher P1NP and NTX levels at 7 d. The IUGR group had thinner trabecular thickness (Tb.Th), lower trabecular number (Tb.N), and increased trabecular separation (Tb.Sp) at 56 d. Conclusion: The effect of IUGR on bone development may persist after birth.

Deficits in anthropometric indices of nutritional status and motor performance among low birth weight children from Maputo City, Mozambique

OBJECTIVE

To evaluate associations between low birth weight (LBW) and anthropometry, body composition, physical fitness, and gross motor coordination among schoolchildren from Maputo, Mozambique.

METHODS

A total of 353 children aged 7 to 10 years old from both genders born in Maputo (Mozambique) were sampled. The sample was divided into two groups: LBW (n = 155) and normal birth weight (NBW, n = 198). Body composition measurements and indices weight-for-age, height-for-age, and weight-for-height were assessed. Physical fitness was assessed by handgrip strength, flexibility, agility, long jump, and running speed. Gross motor coordination was evaluated by using the Korper Koordination Test fur Kinder (KTK) battery.

RESULTS

LBW children were lighter and smaller than NBW children with reduced indices for weight-for-age and height-for-age. They also showed a reduced performance in handgrip strength and sideways movement tests. These differences remained significant even after adjustment for age, gender, body size, and fatness skinfold thickness.

CONCLUSION

LBW seems to be the major factor that influences anthropometry, and is a predictor of low muscle strength and low performance on sideways movement tests. This result suggests that growth faltering in LBW children is associated with adverse health consequences, even after controlling for gender, age, fatness, and body size.

Birth Weight Could Influence Bone Mineral Contents of 10- to 18-Year-Old Korean Adolescents: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) 2010

BACKGROUND

We investigate the relationship between birth weight (BW) and bone mineral content (BMC) in Korean adolescents.

METHODS

Data were obtained from the Korea National Health and Nutrition Examination Survey conducted in 2010. Baseline characteristics were compared according to age- and sex-specific BMC quartiles of total body less head (TBLH), lumbar spine (LS) and femur neck (FN) in 10- to 18-year-old adolescents (male = 474, female = 394).

RESULTS

BW showed a positive correlation with current weight-SDS (p = 0.006 in males, p = 0.008 in females). BW according to TBLH-BMC quartile groups (p for trend <0.003 in males, <0.0001 in females), LS-BMC quartile groups (p for trend <0.034 in males) and FN-BMC quartile groups (p for trend <0.008 in males, <0.020 in females) showed significant differences. The odds ratio (OR) of being in the highest BMC quartile, per 1-kg increase in BW, was significantly increased in TBLH-BMC (OR = 2.14 in males, OR = 3.26 in >16-year-old adolescents) and FN-BMC (OR = 2.62 in males, OR = 3.06 in >16-year-old adolescents) after adjusting for age, height, smoking, drinking, metabolic equivalent of task, and gestational age.

CONCLUSION

BW might be one of the determinant factors of BMC in Korean adolescents.

Epigenetic Mechanisms in Bone Biology and Osteoporosis: Can They Drive Therapeutic Choices?

Osteoporosis is a complex multifactorial disorder of the skeleton. Genetic factors are important in determining peak bone mass and structure, as well as the predisposition to bone deterioration and fragility fractures. Nonetheless, genetic factors alone are not sufficient to explain osteoporosis development and fragility fracture occurrence. Indeed, epigenetic factors, representing a link between individual genetic aspects and environmental influences, are also strongly suspected to be involved in bone biology and osteoporosis. Recently, alterations in epigenetic mechanisms and their activity have been associated with aging. Also, bone metabolism has been demonstrated to be under the control of epigenetic mechanisms. Runt-related transcription factor 2 (RUNX2), the master transcription factor of osteoblast differentiation, has been shown to be regulated by histone deacetylases and microRNAs (miRNAs). Some miRNAs were also proven to have key roles in the regulation of Wnt signalling in osteoblastogenesis, and to be important for the positive or negative regulation of both osteoblast and osteoclast differentiation. Exogenous and environmental stimuli, influencing the functionality of epigenetic mechanisms involved in the regulation of bone metabolism, may contribute to the development of osteoporosis and other bone disorders, in synergy with genetic determinants. The progressive understanding of roles of epigenetic mechanisms in normal bone metabolism and in multifactorial bone disorders will be very helpful for a better comprehension of disease pathogenesis and translation of this information into clinical practice. A deep understanding of these mechanisms could help in the future tailoring of proper individual treatments, according to precision medicine's principles.

PHYSICAL FITNESS AND BIRTH WEIGHT IN YOUNG MEN FROM MAPUTO CITY, MOZAMBIQUE

ABSTRACT Introduction: Birth weight has been considered an important marker of the nutritional transition in developing countries. Objective: To evaluate the influence of birth weight on body composition and physical fitness of young men born in Maputo, Mozambique. Methods: One hundred and seventy-nine students (aged 19 to 22 years) were divided into four groups (low birth weight < 2.500 g, LBW, n = 49; insufficient birth weight ≥ 2.500 g and < 3.000 g, IBW, n = 27; normal birth weight ≥ 3.000 g and < 3.999 g, NBW, n = 74; and high birth weight > 3.999 g, HBW, n = 31). Anthropometry and body composition were measured. Physical fitness was assessed by handgrip strength, muscle endurance, flexibility, agility, and running speed. Results: IBW showed lower values of body mass and fat free mass while LBW and HBW had high values of hip circumference, suprailiac, subscapular and abdominal skinfold when compared to NBW. LBW and HBW showed a high percentage of individuals with low performance in flexibility, right handgrip, agility, abdominal resistance, arms strength, and horizontal long jump. Around 70% of HBW showed low performance in the running speed test. Conclusion: Both low and high birth weight can influence adult adiposity and the performance in physical fitness tests.

Birth weight is positively related to bone size in adolescents but inversely related to cortical bone mineral density: findings from a large prospective cohort study

To examine the influence of intrauterine environment on subsequent bone development, we investigated the relationship between birth weight and cortical bone parameters, and the role of puberty, bone resorption and insulin as possible mediators. Bone outcomes were obtained from mid-tibial pQCT scans performed at age 15.5 years in 1960 males and 2192 females from the ALSPAC birth cohort. Birth weight was positively related to periosteal circumference (PC) [beta=0.40 (0.34, 0.46)], which was largely but not completely attenuated after adjustment for height and weight [beta=0.07 (0.02, 0.12)] (SD change in outcome per 1 kg increase in birth weight with 95% CI). Based on our height and weight adjusted model, the association was stronger in females compared to males (P=0.02 for gender interaction), and persisted in 2842 participants with equivalent results at age 17.7 years. Conversely, birth weight was inversely related to cortical bone mineral density (BMDC) at age 15.5 years after adjusting for height and weight [beta=-0.18 (-0.23, -0.13)], with a stronger association in males compared to females (P=0.01 for gender interaction), but an equivalent association was not seen at 17.7 years. In further analyses performed on data from age 15.5 years, the association between birth weight and PC was unaffected by adjustment for puberty (Tanner stage at age 13.5 years), bone resorption (fasting beta-carboxyterminal cross linking telopeptide (βCTX) at age 15.5 years) or insulin (fasting insulin at age 15.5 years). In contrast, the association with BMDC was attenuated by approximately 30% after adjustment for puberty or bone resorption, and by 50% after adjustment for both factors combined. We conclude that the inverse relationship between birth weight and BMDC is in part mediated by effects of puberty and bone resorption, which may help to explain the transitory nature of this association, in contrast to the more persisting relationship with PC.

Dietary protein's and dietary acid load's influence on bone health

A variety of genetic, mechano-response-related, endocrine-metabolic, and nutritional determinants impact bone health. Among the nutritional influences, protein intake and dietary acid load are two of the factors most controversially discussed. Although in the past high protein intake was often assumed to exert a primarily detrimental impact on bone mass and skeletal health, the majority of recent studies indicates the opposite and suggests a bone-anabolic influence. Studies examining the influence of alkalizing diets or alkalizing supplement provision on skeletal outcomes are less consistent, which raises doubts about the role of acid-base status in bone health. The present review critically evaluates relevant key issues such as acid-base terminology, influencing factors of intestinal calcium absorption, calcium balance, the endocrine-metabolic milieu related to metabolic acidosis, and some methodological aspects of dietary exposure and bone outcome examinations. It becomes apparent that for an adequate identification and characterization of either dietary acid load's or protein's impact on bone, the combined assessment of both nutritional influences is necessary.

Growth from birth to adulthood and bone phenotype in early old age: a British birth cohort study

There is growing evidence that early growth influences bone mass in later life but most studies are limited to birth weight and/or early infant growth and dual-energy X-ray absorptiometry (DXA) measurements. In a British birth cohort study with prospective measures of lifetime height and weight, we investigated the growth trajectory in relation to bone in males (M) and females (F) at 60 to 64 years old. Outcomes were DXA measures of hip and spine areal bone density (aBMD) (n = 1658) and pQCT measures of distal and diaphyseal radius cross-sectional area (CSA), strength, and volumetric bone density (vBMD) (n = 1350 of the 1658). Regression models examined percentage change in bone parameters with standardized measures of birth weight, height, and weight. A series of conditional growth models were fitted for height and weight gain (using intervals: birth-2, 2-4, 4-7, 7-15, 15-20, 20-36, and 36-64 years) and height gain (using intervals: 2-4, 4-7, 7-15, and 15-36 years). Birth weight was positively related to bone CSA (M: 1.4%; 95% confidence interval [CI], 0.3%-2.5%; F: 1.3%; 95% CI, 0.3%-2.4% per 1 SD increase in birth weight for diaphyseal CSA) and strength (M: 1.8%; 95% CI, 0.3-3.4; F: 2.0%; 95% CI, 0.5-3.5). No positive associations were found with trabecular, total, or cortical vBMD. One SD change in prepubertal and postpubertal height and weight velocities were associated with between 2% and 5% greater bone CSA and strength. Height gain in later years was negatively associated with trabecular vBMD. Weight gain velocity during the adult years was positively associated with up to 4% greater trabecular and total BMD, and 4% greater aBMD at hip and spine. In a cohort born in the early post-war period, higher birth weight, gaining weight and height faster than others, particularly through the prepubertal and postpubertal periods, was positively related to bone strength, mostly through greater bone CSA, at 60 to 64 years.

Birth weight and adult bone metabolism are unrelated: results from birth weight-discordant monozygotic twins

Low birth weight (BW) has been associated with poor bone health in adulthood. The aim of this study was to investigate the association between BW and bone mass and metabolism in adult BW-discordant monozygotic (MZ) twins. A total of 153 BW-extremely discordant MZ twin pairs were recruited from the Danish Twin Registry. Serum vitamin D (25-hydroxyvitamin D [25OHD]) and bone turnover markers (BTMs) amino-terminal propeptide of type I procollagen (P1NP), pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (1CTP), and cross-linked C-telopeptide (CTX) were quantified. Femoral neck (FN), total hip (TH), lumbar spine (LS), and whole-body (WB) bone mineral density (BMD) (ie, FN-BMD, TH-BMD, LS-BMD, and WB-BMD, respectively) were measured using dual-energy X-ray absorptiometry (DXA). Twins were studied as single individuals using regression analyses with or without adjustment for height, weight, age, sex, and intrapair correlation. Within-pair differences were assessed using Student's t test and fixed-regression models. BW was not associated with BTMs, LS-BMD, TH-BMD, FN-BMD, or WB-BMD, but BW was associated with WB-BMC, and WB-Area after adjustments. Compared to the co-twin, twins with the highest BW were heavier and taller in adulthood (mean differences ± SD): 3.0 ± 10.5 kg; 1.6 ± 2.6 cm; both p < 0.001). Within-pair analyses showed that LS-BMD, TH-BMD, and FN-BMD tended to be higher in twins with highest BW (for all: mean difference 0.01 ± 0.1 g/cm(2) ; p = 0.08, 0.05, and 0.10, respectively). No difference was observed after adjustment for adult body size. Intrapair differences in BW were not associated with differences in any of the biochemical parameters or BMD. Small differences between twins in BMD were explained by dissimilarities in body size. These results suggest that BW and adult bone metabolism are unrelated.

Life-course evidence of birth weight effects on bone mass: systematic review and meta-analysis

A systematic review of the literature was performed in July 2011. Original papers based on longitudinal studies measuring spine, femoral neck, or total body bone mass by DXA were included (n = 17). Birth weight was positively associated with bone mass among children. The association was unclear among adolescents and weak among adults. This study aims to evaluate the association between birth weight and bone mass in future ages through a systematic review of literature and meta-analysis. A systematic review of the literature was performed in July 2011 in Medline, Web of Science and LILACS bases using key terms: ("birth size" OR "birth weight" OR birthweight OR prematurity OR premature OR "gestational age") AND (osteoporosis OR "bone mass" OR "bone density" OR "bone mineral density" OR "bone mineral content" OR "bone area") AND (longitudinal OR cohort). Original papers based on longitudinal studies measuring lumbar spine, femoral neck or total body bone mass by dual-emission X-ray absorptiometry (DXA) were included. A meta-analysis was performed using birth weight and bone mass density and/or content as continuous variables and adjusted for current height and/or weight. A total of 218 articles were retrieved from which 17 were selected and grouped into three categories according to age: studies with children; with adolescents and young adults, and studies with adults (older than 25). Five papers were included in the meta-analysis. Positive association between birth weight and bone mass was clear among children, unclear among adolescents, and weak among adults. The effect on bone mass content was stronger than those on body mass density regardless of age. Birth weight influences positively bone health in later life. Preventive health policies dealing with early-life modifiable risk factors, as birth weight, should be encouraged to attain an optimal peak bone mass as an strategy to decrease osteoporosis in the elderly.

Influence of pre- and peri-natal nutrition on skeletal acquisition and maintenance

Early life nutrition has substantial influences on postnatal health, with both under- and overnutrition linked with permanent metabolic changes that alter reproductive and immune function and significantly increase metabolic disease risk in offspring. Since perinatal nutrition depends in part on maternal metabolic condition, maternal diet during gestation and lactation is a risk factor for adult metabolic disease. Such developmental responses may be adaptive, but might also result from constraints on, or pathological changes to, normal physiology. The rising prevalence of both obesity and osteoporosis, and the identification of links among bone, fat, brain, and gut, suggest that obesity and osteoporosis may be related, and moreover that their roots may lie in early life. Here we focus on evidence for how maternal diet during gestation and lactation affects metabolism and skeletal acquisition in humans and in animal models. We consider the effects of overall caloric restriction, and macronutrient imbalances including high fat, high sucrose, and low protein, compared to normal diet. We then discuss potential mechanisms underlying the skeletal responses, including perinatal developmental programming via disruption of the perinatal leptin surge and/or epigenetic changes, to highlight unanswered questions and identify the most critical areas for future research.

Insights into the programming of bone development from the Avon Longitudinal Study of Parents and Children (ALSPAC)

We examined associations between proxy measures of in utero nutrition and total body bone mineral content (BMC), bone area (BA), and bone mineral density (BMD) assessed at age 9.9 y in the Avon Longitudinal Study of Parents and Children (ALSPAC). There were positive relations between birth weight and BMC, BA, and BMD. These associations were explained by the co-association of birth weight with body size in later childhood. In height- and weight-adjusted analyses, an inverse association was observed between birth weight and BMD at age 9.9 y, which suggests that birth weight had a negative influence on bone mass after relations with bone and body size were taken into account. In analyses of associations between bone mass at age 9 y and background ultraviolet B exposure during the third trimester of pregnancy (a proxy measure for maternal vitamin D status), maternal ultraviolet B exposure was positively related to BMC, BA, and BMD. After adjustment for height, these associations were only partially attenuated, which suggests that maternal ultraviolet B exposure affected skeletal size and mass independently of longitudinal growth, possibly by the increase of periosteal expansion. There was a positive relation between maternal folate intake and BMD of the spine subregion independent of body size. Although a co-association with folate intake in childhood could explain this relation, the maternal methylenetetrahydrofolate reductase (MTHFR) genotype affected spine BMD independently of the child MTHFR genotype, which suggests that maternal folate status has an independent effect on bone development of offspring. Together, these results confirm that there is a relation between bone development in childhood and several proxy measures for nutritional status in utero.

Are early growth and nutrition related to bone health in adolescence? The Copenhagen Cohort Study of infant nutrition and growth

BACKGROUND

It is generally accepted that peak bone mass affects later fracture risk in the elderly. The extent to which early nutrition and growth can program later bone health has been examined in only a few studies. In the Copenhagen Cohort Study we showed that breastfed infants had significantly higher serum (s)-osteocalcin concentration than did formula-fed infants.

OBJECTIVE

We investigated whether early nutrition and early growth are associated with later bone mass in adolescence.

DESIGN

Participants were examined at birth; at ages 2, 6, and 9 mo (n = 143); and at age 17 y (n = 109) with anthropometric and s-osteocalcin measures and whole-body dual-energy X-ray absorptiometry (DXA) scanning (age 17 y only). Total body (T) and lumbar spine (LS) DXA values were used.

RESULTS

The duration of exclusive breastfeeding was positively correlated with the sex-adjusted LS bone mineral content (BMC), LS bone area (BA), and LS bone mineral density (BMD) (all P < 0.03) and with size-adjusted LS-BMC (P = 0.075) at 17 y of age. s-Osteocalcin at 6 mo was positively correlated with sex-adjusted LS-BMC and LS-BMD (both P < 0.04) and with size-adjusted LS-BMC (P = 0.047) at 17 y of age. Weight and length at 9 mo and increase in weight and length during the first 9 mo of life were positively correlated with sex-adjusted T-BMC and T-BA at age 17 y (all P < 0.04).

CONCLUSIONS

Early body size and growth in infancy are related to bone mass in late adolescence. Furthermore, the duration of exclusive breastfeeding and the markers of bone turnover at 6 mo seem to be positively related to LS bone mass at age 17 y.

Birth weight a negative determinant of whole body bone mineral apparent density in a group of adolescent boys

The aim of this study was to explore the relation between birth weight and bone mass in a group of adolescent boys. This study included 44 adolescent (aged 14-20yr) boys. Anthropometric characteristics (height and weight) were measured and birth weights were obtained from the obstetric records. Body composition was assessed by dual-energy X-ray absorptiometry (DXA). Bone mineral content (BMC) and bone mineral density (BMD) of the whole body (WB) and the lumbar spine (L2-L4) were also assessed by DXA. Calculations of the bone mineral apparent density (BMAD) were completed for the WB and at the lumbar spine (L2-L4). The expressions WB BMC/height and WB BMD/height were calculated to adjust for WB bone size. Birth weight was positively correlated to body weight (r=0.37; p<0.05), body mass index (r=0.38; p<0.01), body fat percentage (r=0.44; p<0.01), and negatively associated with WB BMAD (r=-0.46; p<0.01). In conclusion, this study suggests that birth weight is a positive determinant of body weight, body mass index, and body fat percent but a negative determinant of WB BMAD in adolescent boys.