Association between maternal blood lipids during pregnancy and offspring growth trajectories in a predominantly macrosomic cohort: findings from the ROLO longitudinal birth cohort study

The purpose of this study is to examine associations between maternal lipid profiles in pregnancy and offspring growth trajectories in a largely macrosomic cohort. This is a secondary analysis of the ROLO birth cohort (n = 293), which took place in the National Maternity Hospital, Dublin, Ireland. Infants were mostly macrosomic, with 55% having a birthweight > 4 kg. Maternal mean age was 32.4 years (SD 3.9 years), mean BMI was 26.1 kg/m2 (SD 4.4 kg/m2) and 48% of children born were males. Total cholesterol, high density lipoprotein cholesterol (HDL-cholesterol), low density lipoprotein cholesterol (LDL-cholesterol) and triglycerides were measured from fasting blood samples of mothers at 14 and 28 week gestation. The change in maternal lipid levels from early to late pregnancy was also examined. Offspring abdominal circumference and weight were measured at 20- and 34-week gestation, birth, 6 months, 2 years and 5 years postnatal. Linear spline multilevel models examined associations between maternal blood lipid profiles and offspring growth. We found some weak, significant associations between maternal blood lipids and trajectories of offspring growth. Significant findings were close to the null, providing limited evidence. For instance, 1 mmol/L increase in maternal triglycerides was associated with faster infant weight growth from 20- to 34-week gestation (0.01 kg/week, 95% CI - 0.02, - 0.001) and slower abdominal circumference from 2 to 5 years (0.01 cm/week, 95% CI - 0.02, - 0.001). These findings do not provide evidence of a clinically meaningful effect.    Conclusion: These findings raise questions about the efficacy of interventions targeting maternal blood lipid profiles in pregnancies at risk of macrosomia. New studies on this topic are needed. What is Known: • Maternal fat accumulation during early pregnancy may potentially support fetal growth in the third trimester by providing a reserve of lipids that are broken down and transferred to the infant across the placental barrier. • There are limited studies exploring the impact of maternal lipid profiles on infant and child health using growth trajectories spanning prenatal to postnatal life. What is New: • Maternal blood lipid profiles were not associated with offspring growth trajectories of weight and abdominal circumference during pregnancy up to 5 years of age in a largely macrosomic cohort, as significant findings were close to the null, providing limited evidence for a clinically meaningful relationship. • Strengths of this work include the use of infant growth trajectories that span prenatal to postnatal life and inclusion of analyses of the change of maternal lipid levels from early to late pregnancy and their associations with offspring growth trajectories from 20-week gestation to 5 years of age.

Assessment of serum total 25-hydroxyvitamin D assays for Vitamin D External Quality Assessment Scheme (DEQAS) materials distributed at ambient and frozen conditions

The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at -40 °C prior to distribution and the participants are instructed to store the samples frozen at -20 °C or lower after receipt; however, the samples are shipped to participants at ambient conditions (i.e., no temperature control). To address the question of whether shipment at ambient conditions is sufficient for reliable performance of various 25(OH)D assays, the equivalence of DEQAS human serum samples shipped under frozen and ambient conditions was assessed. As part of a Vitamin D Standardization Program (VDSP) commutability study, two sets of the same nine DEQAS samples were shipped to participants at ambient temperature and frozen on dry ice. Twenty-eight laboratories participated in this study and provided 34 sets of results for the measurement of 25(OH)D using 20 ligand binding assays and 14 liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Equivalence of the assay response for the frozen versus ambient DEQAS samples for each assay was evaluated using multi-level modeling, paired t-tests including a false discovery rate (FDR) approach, and ordinary least squares linear regression analysis of frozen versus ambient results. Using the paired t-test and confirmed by FDR testing, differences in the results for the ambient and frozen samples were found to be statistically significant at p < 0.05 for four assays (DiaSorin, DIAsource, Siemens, and SNIBE prototype). For all 14 LC-MS/MS assays, the differences in the results for the ambient- and frozen-shipped samples were not found to be significant at p < 0.05 indicating that these analytes were stable during shipment at ambient conditions. Even though assay results have been shown to vary considerably among different 25(OH)D assays in other studies, the results of this study also indicate that sample handling/transport conditions may influence 25(OH)D assay response for several assays.

Central vein sign: A diagnostic biomarker in multiple sclerosis (CAVS-MS) study protocol for a prospective multicenter trial

The specificity and implementation of current MRI-based diagnostic criteria for multiple sclerosis (MS) are imperfect. Approximately 1 in 5 of individuals diagnosed with MS are eventually determined not to have the disease, with overreliance on MRI findings a major cause of MS misdiagnosis. The central vein sign (CVS), a proposed MRI biomarker for MS lesions, has been extensively studied in numerous cross sectional studies and may increase diagnostic specificity for MS. CVS has desirable analytical, measurement, and scalability properties. "Central Vein Sign: A Diagnostic Biomarker in Multiple Sclerosis (CAVS-MS)" is an NIH-supported, 2-year, prospective, international, multicenter study conducted by the North American Imaging in MS Cooperative (NAIMS) to evaluate CVS as a diagnostic biomarker for immediate translation into clinical care. Study objectives include determining the concordance of CVS and McDonald Criteria to diagnose MS, the sensitivity of CVS to detect MS in those with typical presentations, and the specificity of CVS among those with atypical presentations. The study will recruit a total of 400 participants (200 with typical and 200 with atypical presentations) across 11 sites. T2*-weighted, high-isotropic-resolution, segmented echo-planar MRI will be acquired at baseline and 24 months on 3-tesla scanners, and FLAIR* images (combination of FLAIR and T2*) will be generated for evaluating CVS. Data will be processed on a cloud-based platform that contains clinical and CVS rating modules. Imaging quality control will be conducted by automated methods and neuroradiologist review. CVS will be determined by Select6* and Select3* lesion methods following published criteria at each site and by central readers, including neurologists and neuroradiologists. Automated CVS detection and algorithms for incorporation of CVS into McDonald Criteria will be tested. Diagnosis will be adjudicated by three neurologists who served on the 2017 International Panel on the Diagnosis of MS. The CAVS-MS study aims to definitively establish CVS as a diagnostic biomarker that can be applied broadly to individuals presenting for evaluation of the diagnosis of MS.

Assessment of serum total 25-hydroxyvitamin D assay commutability of Standard Reference Materials and College of American Pathologists Accuracy-Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) materials: Vitamin D Standardization Program (VDSP) Commutability Study 2

An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum total 25-hydroxyvitamin D [25(OH)D] using ligand binding assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A set of 50 single-donor serum samples were assigned target values for 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] using reference measurement procedures (RMPs). SRM and PT/EQA samples evaluated included SRM 972a (four levels), SRM 2973, six College of American Pathologists (CAP) Accuracy-Based Vitamin D (ABVD) samples, and nine Vitamin D External Quality Assessment Scheme (DEQAS) samples. Results were received from 28 different laboratories using 20 ligand binding assays and 14 LC-MS/MS methods. Using the test assay results for total serum 25(OH)D (i.e., the sum of 25(OH)D2 and 25(OH)D3) determined for the single-donor samples and the RMP target values, the linear regression and 95% prediction intervals (PIs) were calculated. Using a subset of 42 samples that had concentrations of 25(OH)D2 below 30 nmol/L, one or more of the SRM and PT/EQA samples with high concentrations of 25(OH)D2 were deemed non-commutable using 5 of 11 unique ligand binding assays. SRM 972a (level 4), which has high exogenous concentration of 3-epi-25(OH)D3, was deemed non-commutable for 50% of the LC-MS/MS assays.

The effects of acute hyponatraemia on bone turnover in patients with subarachnoid haemorrhage: A preliminary report

CONTEXT

Animal data and cross-sectional human studies have established that chronic hyponatraemia predisposes to osteoporosis; the effects of acute hyponatraemia on bone turnover have not been determined. Our objective was to test the hypothesis that acute hyponatraemia leads to dynamic effects on bone turnover.

DESIGN

A prospective observational pilot study.

METHODS

Bone turnover markers [C-terminal crosslinking telopeptide of type 1 collagen (CTX-1), N-propeptide of type 1 collagen (P1NP) and osteocalcin] were measured prospectively over one week in 22 eunatraemic patients with subarachnoid haemorrhage. Patients treated with glucocorticoids were excluded.

RESULTS

Eight patients developed acute hyponatraemia, median nadir plasma sodium concentration 131 mmol/L (IQR 128-132), and 14 remained eunatraemic, nadir plasma sodium concentration 136 mmol/L (IQR 133-137). Significant main effects of hyponatraemia were found for P1NP (p = .02) and P1NP:CTX-1 ratio (p = .02), both fell in patients with acute hyponatraemia, with significant interaction between hyponatraemia and time from baseline for P1NP (p = .02). Significant main effects of time from baseline (p < .001) but not hyponatraemia (p = .07) were found for osteocalcin. For CTX-1, significant main effects of time from baseline (p = .001) but not hyponatraemia (p = .65) were found. There was a positive correlation between change in P1NP:CTX-1 ratio and nadir plasma sodium concentration, r = +.43, p = .04. Median serum cortisol (measured on days 1, 3 and 7) was higher in the hyponatraemia group than in those who remained eunatraemic, 545 nmol/L (IQR 373-778) versus 444 nmol/L (IQR 379-542) p = .03.

CONCLUSION

These data suggest that acute mild hyponatraemia is associated with a reduction in bone formation activity.

SUN-352 The Effects of Acute Hyponatremia on Bone Remodeling Markers in Patients with Subarachnoid Hemorrhage

Animal data and cross-sectional human studies have established that chronic hyponatremia predisposes to osteoporosis; the effects of acute hyponatremia on bone remodeling are unknown. Serum markers of bone remodeling (total procollagen type 1 amino-terminal propeptide (P1NP), bone specific alkaline phosphatase (bone ALP), N-mid-osteocalcin (OCI) and C-terminal teleopeptides of type I collagen (CTX-1)) were assessed in a cohort of patients admitted with subarachnoid hemorrhage (SAH), who were prospectively studied over seven days. The ratio of P1NP:CTX-1 was calculated to report a bone formation index.

Twenty-two patients (13 women), median (IQR) age 53 (47, 62) years were recruited. Patients who developed post-SAH ACTH deficiency and those treated with glucocorticoids, or continuous enteral feeding were excluded. All patients were eunatremic on initial assessment. Eight patients developed acute hyponatremia, median nadir plasma sodium concentration (pNa) 131 (128, 132) mmol/L, and 14 remained eunatremic, nadir pNa 136 (133, 137) mmol/L. The groups were matched for age, 25-hydroxy Vitamin D, PTH, WFSS and Fischer scores. Serum cortisol concentration was greater in the hyponatremic group, 571 (504, 671) nmol/L, than the eunatremic group, 449 (400, 501) nmol/L, p=0.008. Bone remodeling markers and bone formation index (P1NP:CTX-1 ratio) were similar in the two groups at baseline.

There was a significant rise in CTX-1 in both hyponatremic patients, +0.15 (0.09, 0.37) μg/l, p = 0.009, and patients who remained eunatremic, +0.11 (-0.02, 0.23) μg/l, p = 0.04, with no significant difference between the groups. There was, however, a significant fall in P1NP:CTX-1 ratio in patients with acute hyponatremia, p = 0.02, but no significant change in eunatraemic patients, with significant between group difference, p = 0.02.

Changes in P1NP and OCI correlated positively with nadir pNa; r = 0.43, p = 0.04 and r = 0.61, p = 0.001 respectively. In addition, there was a positive correlation between change in P1NP:CTX-1 ratio and nadir pNa, r = 0.43, p = 0.04. There was no correlation between change in OCI or CTX-1 and nadir pNa. Serum cortisol was strongly negatively correlated with change in P1NP (r = -0.64, p = 0.001) but not with change in other bone remodeling markers.

Acute hyponatremia following SAH is associated with a fall in bone formation index; physiological hypercortisolemia may contribute to this. Further analysis with larger numbers will help us determine whether hyponatremia is an independent risk factor.

Vitamin D status and fertility outcomes during winter among couples undergoing in vitro fertilization/intracytoplasmic sperm injection

OBJECTIVE

To assess the vitamin D status of men and women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI), and to investigate associations between vitamin D status and fertility variables.

METHODS

A cross-sectional prospective study was undertaken of men and women attending a fertility clinic in Ireland for IVF/ICSI between January and March 2014. Vitamin D status was determined by measurement of serum 25-hydroxyvitamin D (25(OH)D). Questionnaires examined knowledge and practices concerning vitamin D. Fertility variables and pregnancy outcomes were assessed in relation to vitamin D status.

RESULTS

Overall, 73 men and 64 women provided blood samples. Among men, no correlation was found between 25(OH)D and total motility (ρ=0.069, P=0.562), progressive motility (ρ=0.066, P=0.576), count (ρ=0.001, P=0.996), or morphology (ρ=-0.034, P=0.774) of sperm. Additionally, there was no association between 25(OH)D and ongoing pregnancy rates (P=0.158). There was no difference in 25(OH)D between men with and without male factor subfertility issues (P=0.856). Among women, there was no significant correlation between 25(OH)D and anti-Müllerian hormone (P=0.629) or number of collected (P=0.198) and fertilized oocytes (P=0.136). There was no difference in 25(OH)D between women with and without ongoing pregnancy (P=0.222).

CONCLUSION

No correlation was found between fertility variables or pregnancy outcomes and male or female vitamin D status.

Striking difference of periarticular bone density change in early psoriatic arthritis and rheumatoid arthritis following anti-rheumatic treatment as measured by digital X-ray radiogrammetry

OBJECTIVES

To examine changes in hand BMD as measured by digital X-ray radiogrammetry (DXR-BMD) in early PsA compared with RA patients prior to and 3 and 12 months after introducing an antirheumatic treatment. Further, to identify predictors for hand bone loss at the time of disease presentation.

METHODS

Recent-onset, active, treatment-naïve patients were recruited. Clinical assessment, hand X-rays and DXR were obtained at 0, 3 and 12 months. Mean DXR-BMD for both hands and changes in DXR-BMD (mg/cm(2)/month) were compared between the two groups. We compared baseline disease characteristics of patients with normal hand DXR-BMD with those with bone loss. Logistic regression analyses were performed to identify predictors of hand BMD loss.

RESULTS

A total of 64 patients were included. Hand DXR-BMD decreased in RA throughout the study (P = 0.043). Changes in periarticular bone density over 12 months differed between PsA and RA (P = 0.001). Hand bone loss at 3 months was associated with elevated BMI [odds ratio (OR) = 3.59, P = 0.041] and heavier alcohol intake (OR = 1.13, P = 0.035). Diagnosis of RA (OR = 57.48, P = 0.008), heavier alcohol intake (OR = 1.27, P = 0.012) and higher swollen joint count (SJC28) (OR = 1.5, P = 0.036) were independent predictors for hand bone loss in the first year.

CONCLUSION

Following treatment, we found ongoing hand bone loss in RA and unchanged periarticular bone density in PsA, supporting the hypothesis that different pathomechanisms are involved in hand bone remodelling in PsA. Presence of RA, heavier alcohol intake and higher SJC were identified as independent predictors for hand bone loss over 1 year.

Inadequate vitamin D levels are associated with culture positive sepsis and poor outcomes in paediatric intensive care

AIM

This study aimed to assess vitamin D status, and its determinants, in paediatric patients with suspected sepsis who were admitted to a paediatric intensive care unit (PICU). We also investigated the association between vitamin D status and clinical outcomes.

METHODS

Serum 25-hydroxy vitamin D (25OHD) and clinical determinants were prospectively assessed in children with suspected sepsis (<12 years old) admitted to the PICU. The relationship between 25OHD and clinical outcomes was evaluated. Vitamin D status was also assessed in control children of a similar age.

RESULTS

We enrolled 120 children with suspected sepsis admitted to the PICU and 30 paediatric controls. 25OHD was <50 nmol/L in 59% of the children admitted to the PICU and 25OHD was lower than in the controls (47 ± 29 vs 66 ± 26 nmol/L, p < 0.001). After adjusting for potential confounders, 25OHD was strongly associated with culture positive sepsis (p < 0.001), the paediatric index of mortality (p = 0.026) and the duration of mechanical ventilation (p = 0.008). There was a negative correlation between 25OHD and C-reactive protein (CRP): each 0.1% decrease in 25OHD increased CRP (p = 0.04).

CONCLUSION

Children admitted to the PICU with suspected sepsis had lower 25OHD than controls and inadequate 25OHD status was associated with confirmed sepsis and poor outcomes.

Association between vitamin D status and physical function in the severely obese

CONTEXT

Mortality is 85% higher in severely obese subjects (body mass index [BMI] > 40 kg/m(2)) than in subjects with a healthy BMI; poor physical function may be contributory. Hypovitaminosis D is common in obese subjects and is associated with physical dysfunction in the elderly.

OBJECTIVE

We determined the relationship between vitamin D status and physical function in severely obese subjects.

DESIGN, SETTING, AND PATIENTS

We conducted a clinic-based, cross-sectional study of severely obese subjects. Participants were stratified into three groups according to the Institute of Medicine (IOM) vitamin D status categorization.

MAIN OUTCOME MEASURES

We compared levels of self-reported activity and times taken to walk 500 m and to ascend and descend a 17-cm step 50 times.

RESULTS

We recruited 252 subjects (age, 43.7 ± 11.2 y; BMI, 50.7 ± 9.7 kg/m(2)); 25-hydroxyvitamin D (25OHD) concentrations were less than 30 nmol/L in 109 participants. Participants with a 25OHD > 50 nmol/L, compared to those with a 25OHD < 30 nmol/L, had the highest activity levels (3.1 ± 3.4 h/wk versus 1.5 ± 2.5 h/wk; P = .015) and the shortest 500-m walk times (6.2 ± 1.1 min versus 7.4 ± 1.5 min; P = .003). Serum 25OHD concentrations had a weakly positive association with activity level (r = 0.19; P = .008) and a moderately negative association with 500-m walk time (r = -0.343; P < .001).

CONCLUSIONS

Vitamin D status had a significant relationship with physical activity and physical function in this cohort of severely obese subjects. Low activity levels are likely to perpetuate the problem of hypovitaminosis D due to less time spent outdoors. Studies exploring the effects of vitamin D supplementation in this population are warranted.

Hungry bone syndrome and normalisation of renal phosphorus threshold after total parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia: a case report

INTRODUCTION

This is the first report of which the authors are aware to describe this c.2166delinsGG mutation in X-linked hypophosphataemia and to describe normalisation of renal threshold for phosphate excretion after parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia.

CASE PRESENTATION

We present the case of a 34-year-old Caucasian woman with X-linked hypophosphataemia. She developed tertiary hyperparathyroidism with markedly high bone turnover requiring total parathyroidectomy and had prolonged requirement for intravenous calcium infusion after surgery. She had a novel mutation in her phosphate-regulating gene with homologies to endopeptidases on the X-chromosome and had an unusual degree of dependence on phosphate supplementation. Prior to operative intervention she had a trial of cinacalcet that improved bone turnover markers when used in isolation but which led to a paradoxical rise in parathyroid hormone levels when given with phosphate supplementation. After correction of hungry bone syndrome, the renal phosphorus threshold normalised as a manifestation of hypoparathyroid state despite marked elevation in level of fibroblast growth factor 23.

CONCLUSIONS

This case illustrates the risk of tertiary hyperparathyroidism as a complication of treatment for hypophosphataemia; it highlights the morbidity associated with hungry bone syndrome and provides novel insight into renal handling of phosphorus.

Pregnancy in dark winters: implications for fetal bone growth?

OBJECTIVE

To prospectively examine the prevalence of hypovitaminosis D in pregnancy and to correlate maternal and fetal vitamin D to fetal anthropometry.

DESIGN

A prospective cohort study.

SETTING

Tertiary referral maternity hospital.

PATIENT(S)

Sixty pregnant women.

INTERVENTION(S)

Serum 25-hydroxyvitamin D (25OHD) was measured in early pregnancy, at 28 weeks, and in cord blood at delivery.

MAIN OUTCOME MEASURE(S)

The prevalence of hypovitaminosis D and the relationship between fetal growth and serum 25OHD concentrations.

RESULT(S)

Two subgroups were analyzed to examine results in the context of seasonal variation in 25OHD: a winter and a summer cohort. Fetal anthropometry was assessed at 20 and 34 weeks, and at delivery the neonatal anthropometry was recorded. There was a high prevalence of hypovitaminosis D ranging from 33% to 97%, with a marked seasonal variation. Fetal 25OHD concentrations correlated with all biometry at 20 weeks. In the winter cohort, a correlation was found between early pregnancy 25OHD and femur length at 20 weeks, and between 28-week 25OHD and femur length at 34 weeks. Infant length was shorter in those with early pregnancy 25OHD less than the median (52.1 vs. 53.6 cm).

CONCLUSION(S)

The high prevalence of maternal hypovitaminosis D during winter months in northern latitudes may have detrimental effects on fetal skeletal growth.

The relationship between maternal and fetal vitamin D, insulin resistance, and fetal growth

Evidence for a role of vitamin D in maintaining normal glucose homeostasis is inconclusive. We sought to clarify the relationship between maternal and fetal insulin resistance and vitamin D status. This is a prospective cohort study of 60 caucasian pregnant women. Concentrations of 25-hydroxyvitamin D (25-OHD), glucose, insulin, and leptin were measured in early pregnancy and at 28 weeks. Ultrasound at 34 weeks assessed fetal anthropometry including abdominal wall width, a marker of fetal adiposity. At delivery birth weight was recorded and fetal 25-OHD, glucose, C-peptide, and leptin measured in cord blood. Insulin resistance was calculated using the Homeostasis Model Assessment (HOMA) equation. We found that those with lower 25-OHD in early pregnancy had higher HOMA indices at 28 weeks, (r = -.32, P = .02). No significant relationship existed between maternal or fetal leptin and 25-OHD, or between maternal or fetal 25-OHD and fetal anthropometry or birth weight. The incidence of vitamin D deficiency was high at each time point (15%-45%). These findings lend support to routine antenatal supplementation with vitamin D in at risk populations.