Bone marker status in mothers and their newborns in Iran

High maternal osteocalcin levels during pregnancy is associated with low birth weight infants: A nested case-control study in China

BACKGROUND

Low birth weight infants (LBW) are at risk of chronic diseases in later life due to the disorder of energy metabolism during pregnancy. Osteocalcin (OC) has been identified as a hormone that regulate energy metabolism. However, few studies have researched on the associations between maternal serum OC levels and low birth weight infants.

OBJECTIONS

To examine the associations between maternal serum OC concentrations and LBW.

METHODS

This was a nested case-control study involving a total of 230 pregnant women delivering LBW and 382 control pregnant women (matched for infant gender, gestational age at blood draw, region of Maternity and Child Healthcare Hospital and maternal age in 1: (1-2) ratio). One serum sample was collected from each pregnant woman at 5-35 weeks' gestation. Pregnant women were divided into 3 groups (1st, 2nd and 3rd trimester group). There were 60 and 142 and 28 pregnant women delivering LBW in the first, second and third trimester, respectively. Similarly, there were 101 and 233 and 48 controls in the first, second and third trimester, respectively. Maternal serum OC and 25(OH)D concentrations were categorized into low and high levels, the low level used as reference in analyses. Binary logistic regression model was used to compute odd radio (ORs) for LBW according to levels of maternal serum OC and 25(OH)D.

RESULTS

Compared with the subjects in low level in first trimester, LBW was two times as likely to occur among pregnancy women with high serum OC concentrations (OR = 2.04, 95%CI:1.05-3.96). After adjusted for confounding factors, a significant positive relationship still existed (adjusted ORs = 2.29, 95%CI: 1.11-4.72). In second trimester, women in high level of serum OC had nearly 1.6 times the risk of delivering LBW infants as those in the low level (OR = 1.55, 95%CI: 1.01-2.37). After adjusted for confounding factors, the ORs increased (ORs = 1.59, 95%CI:1.03-2.45). No significant associations were found between maternal serum OC levels and LBW in third trimester. In addition, there were no associations between maternal 25(OH)D concentrations and LBW during pregnancy.

CONCLUSION

High maternal serum OC levels in the first or the second trimester during pregnancy may be associated with the risk of LBW.

Impact of vitamin D supplementation on markers of bone mineral metabolism in term infants

25-Hydroxyvitamin D (25OHD) may influence bone turnover. We compared the dynamics of bone markers in 30 infants on vitamin D supplementation (≅550 IU/day) with different degrees of hypovitaminosis D (25OHD <11 ng/ml - deficiency vs. ≥ 11 <20 ng/ml - insufficiency). Baseline and follow-up (after 10 weeks), 25OHD, 1,25-dihydroxyvitamin D (1,25(OH)(2)D), alkaline phosphatase (ALP), PTH, osteocalcin (OC), N-terminal propeptide of type I procollagen (PINP), C-terminal telopeptide of type I collagen (CTX), and amino-terminal propeptide of C-type natriuretic peptide (NT-proCNP) were measured. None of the newborns had craniotabes, hypocalcemia or hyperparathyroidism. The median (Q1;Q3) 25OHD increased from a baseline of 8.45 (7;11.9) ng/ml to 54.6 (34.7;67.3) ng/ml (p<0.001). The baseline 25OHD negatively correlated with total increment of 25OHD (r=-0.54; p=0.002). There were changes in ALP (241 vs. 331 IU; p<0.001), 1,25(OH)(2)D (48 vs. 95.5 pg/ml, p<0.001), OC (88.8 vs. 159.1 ng/ml, p<0.001), PINP (3886 vs. 2409 ng/ml; p<0.001), CTX (1.6 vs. 1.1 ng/ml; p<0.001), and NT-proCNP (75.1 vs. 35.1 pmol/l; p<0.001). Vitamin D deficient infants at baseline, compared to the insufficient group, revealed significantly higher percentage changes for 25OHD (745% vs. 167%, p<0.0001), OC (113% vs. 40%, p<0.05) and 1,25(OH)(2)D (95% vs. 58%, p<0.05).

CONCLUSIONS

Vitamin D supplements had little to no impact on markers of bone turnover in term infants in the first few months of life, with the exception of osteocalcin. Ten weeks of cholecalciferol supplementation at a dose of 550 IU/day led to a marked increase of 25OHD concentration. The magnitude of 25OHD increment was inversely related to vitamin D status at baseline. Irrespective of the severity of vitamin D deficiency, a secondary hyperparathyroidism with elevated iPTH, ALP, phosphaturia or hypophosphatemia was not observed in the studied neonates.

The influence of folic acid supplementation on maternal and fetal bone turnover

The aim of our study was to investigate the relationship between maternal and fetal bone turnover markers and folic acid supplementation during pregnancy. In an observational study performed in Tehran University of Medical Sciences related hospitals, 113 healthy pregnant women with gestational age between 8 and 12 weeks and aged between 15 and 42 years were recruited and followed until delivery time. The participants were divided into two groups; women who took 1 mg of folic acid daily supplement from the beginning of the pregnancy until the end of the second trimester entered into group I and women who choose to continue their daily intake of folic acid until the delivery time entered into group II. The two groups were matched based on the maternal anthropometric data, energy, calcium and vitamin D intake. Following the delivery, venous blood samples were collected from mothers and umbilical cords of the neonates. Maternal and fetal serum concentrations of 25-hydroxy vitamin D3, PTH, osteocalcin (OC), crosslaps and maternal serum level of homocysteine, folate, soluble receptor activator of NF-kappaB ligand (sRANKL), osteoprotegerin (OPG), calcium, and phosphate were measured. Measured birth outcome parameters included weight, length, head circumference, appearance, and respiration. With regard to maternal assessment, the serum levels of OC and OPG and folate were significantly higher in group II compared to group I, while the serum levels of RANKL and homocysteine were significantly higher in group I. We did not find significant differences in serum levels of 25-OH vitamin D, PTH, crosslaps, calcium, or phosphate between the two groups. The neonates from mothers recruited in group II had higher (but not significantly) serum level of OC. We observed that the neonates born from mothers in group II had overall better birth outcome parameters and apgar scores compare to the neonates born from mothers in group I. Our results show that daily supplementation of folic acid during pregnancy could have a positive impact on the bone turnover markers in mothers and their newborns. This may suggest that both pregnant mothers and their fetuses could benefit from positive effects of folic acid taken during the whole period of pregnancy.

Health effects from long-range transported contaminants in Arctic top predators: An integrated review based on studies of polar bears and relevant model species

The aim of this review is to provide a thorough overview of the health effects from the complexed biomagnified mixture of long-range transported industrial organochlorines (OCs), polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs) and mercury (Hg) on polar bear (Ursus maritimus) health. Multiple scientific studies of polar bears indicate negative relationships between exposure to these contaminants and health parameters; however, these are all of a correlative nature and do not represent true cause-and-effects. Therefore, information from controlled studies of farmed Norwegian Arctic foxes (Vulpes lagopus) and housed East and West Greenland sledge dogs (Canis familiaris) were included as supportive weight of evidence in the clarification of contaminant exposure and health effects in polar bears. The review showed that hormone and vitamin concentrations, liver, kidney and thyroid gland morphology as well as reproductive and immune systems of polar bears are likely to be influenced by contaminant exposure. Furthermore, exclusively based on polar bear contaminant studies, bone density reduction and neurochemical disruption and DNA hypomethylation of the brain stem seemed to occur. The range of tissue concentration, at which these alterations were observed in polar bears, were ca. 1-70,000 ng/g lw for OCs (blood plasma concentrations of some PCB metabolites even higher), ca. 1-1000 ng/g lw for PBDEs and for PFCs and Hg 114-3052 ng/g ww and 0.1-50 microg/g ww, respectively. Similar concentrations were found in farmed foxes and housed sledge dogs while the lack of dose response designs did not allow an estimation of threshold levels for oral exposure and accumulated tissue concentrations. Nor was it possible to pinpoint a specific group of contaminants being more important than others nor analyze their interactions. For East Greenland polar bears the corresponding daily SigmaOC and SigmaPBDE oral exposure was estimated to be 35 and 0.34 microg/kg body weight, respectively. Furthermore, PFC concentrations, at which population effect levels could occur, are likely to be reached around year 2012 for the East Greenland polar bear subpopulation if current increasing temporal trends continue. Such proposed reproductive population effects were supported by physiological based pharmacokinetic (PBPK) modelling of critical body residues (CBR) with risk quotients >or=1 for SigmaPCB, dieldrin, SigmaPFC and SigmaOHC (organohalogen contaminant). The estimated daily TEQ for East Greenland polar bears and East Greenland sledge dogs were 32-281-folds above WHO SigmaTEQ guidelines for humans. Compared to human tolerable daily intake (TDI), these were exceeded for PCBs, dieldrin, chlordanes and SigmaHCH in East Greenland polar bears. Comparisons like these should be done with caution, but together with the CBR modelling and T-score estimations, these were the only available tools for polar bear risk evaluation. In conclusion, polar bears seem to be susceptible to contaminant induced stress that may have an overall sub-clinical impact on their health and population status via impacts on their immune and reproductive systems.

Comparison of the Bone Turn-over Markers in Patients with Multiple Sclerosis and Healthy Control Subjects

One of the major concerns for patients with multiple sclerosis (MS) is developing osteoporosis, especially when corticosteroid treatment is used. The aim of the present study is to compare the bone turnover markers in patients with multiple sclerosis and healthy control subjects. A total of 176 subjects were enrolled in this case-control. Ninety-one MS patients with mean age of 35.26 ± 8.76 yrs were randomly selected from the Committee on Multiple Sclerosis Registry. The control group was composed of 85 healthy subjects who were recruited from the Iranian Multicenter Osteoporosis Study (IMOS). Fasting serum levels of parathyroid hormone (PTH), 25 (OH) D3, osteocalcin and cross laps were measured in two groups. Hip and spine BMD were measured using DXA. Our findings showed significant differences in hip BMD and its T-score and Z-score values between MS patients and the control group. Osteoporosis prevalence at hip area of the MS patients was almost 5 times higher than the control group [OR=4.66, (95% CI 0.97 to 22.27), RR=4.29, (95% CI 0.95 to l9.32), p value=0.03]. No significant difference was found in BMD L2-L4, BMD T-score and BMD Z-score of lumbar area between two groups. The PTH and cross laps serum concentrations in MS patients were significantly higher than the control group. We did not find significant difference in serum osteocalcin level between the two groups. We concluded that in our study the serum levels of bone resorbtion markers in MS patients were significantly higher than the healthy control group. This may explain, at least in part, the elevated susceptibility of MS patients for developing osteoporosis.

Prenatal nutrition: a critical window of opportunity for mother and child

The prenatal period encompasses a critical window for future health and functioning of mother and child. Attention previously focused on undernutrition risk (i.e., in developing countries and famine conditions) shifted to mismatch between prenatal 'programming' by undernutrition and postnatal overconsumption (i.e., low birthweight vs rapid postnatal growth), now to overconsumption/overweight throughout the reproductive cycle and short- and long-term health risks, including obesity, diabetes, dyslipidemia and cardiovascular disease. Moreover, overconsumption/overweight do not guarantee adequacy of critical nutrients (i.e., against birth defects or for brain development). Multinutrient supplementation - including zinc, iodine, choline and long-chain polyunsaturated fatty acids, especially n-3 - may have advantages over single-nutrient supplements, for example, iron or folate. Future nutritional care for healthy in utero programming may necessitate individual assessment and follow-up, including preconception nutritional preparation, appropriate weight gain, metabolic balance and food-based regimens enhanced by key nutrient fortification and/or supplementation, warranting further research into nutritional optimization of pregnancy outcomes.

Does the nutrition profile of vitamins, fatty acids and microelements counteract the negative impact from organohalogen pollutants on bone mineral density in Greenland sledge dogs (Canis familiaris)?

There is a great need for understanding the impact from dietary OHCs (organohalogen compounds) on bone mineral composition - and thereby osteoporosis - in especially arctic wildlife such as polar bears (Ursus maritimus) as well as humans. For that purpose, we measured BMD (bone mineral density) by DXA scanning (g/cm(-2)) in 15 age and weight normalized sledge dog (Canis familiaris) bitches and their 26 pups divided into a control group (n=26) given 50-200 g/day clean pork (Suis scrofa) fat and a treated group (n=15) given 50-200 g/day OHC polluted minke whale (Balaenoptera acutorostrata) blubber as main lipid sources. The results showed that BMD increased significantly with age (linear regression: p<0.0001, r(2)=0.83, n=41) while no sex difference was found in the F-generation (two-way ANOVA: all p>0.3). No differences in BMD(femur) or BMD(vertebrae) between exposed and control individuals in the bitch generation were found (linear mixed effect model: both p>0.38). Likewise, no difference between exposed and control subadults and juveniles in the F-generation was found (two-way ANOVA: all p>0.33). Correlation analyses between BMD(femur), BMD(vertebrae) and groups of OHCs, respectively, did not show any statistically significant relationships nor a clear or decreasing trend (Pearson's: p: 0.07-0.78; r: -0.2-0.59; n: 10-18). As the groups were similar regarding genetics, age and sex are the only factors that can explain this observation. Either the pollutants did not have an impact on BMD using the present time frame and OHC concentrations (threshold levels not reached), or the difference in food composition (mainly vitamins and n3 fatty acids) conceal the potential OHC impact on BMD. Such information is important when evaluating the positive and negative health consequences from eating polluted marine species.