REUSED: A deep neural network method for rapid whole-brain high-resolution myelin water fraction mapping from extremely under-sampled MRI

Changes in myelination are a cardinal feature of brain development and the pathophysiology of several central nervous system diseases, including multiple sclerosis and dementias. Advanced magnetic resonance imaging (MRI) methods have been developed to probe myelin content through the measurement of myelin water fraction (MWF). However, the prolonged data acquisition and post-processing times of current MWF mapping methods pose substantial hurdles to their clinical implementation. Recently, fast steady-state MRI sequences have been implemented to produce high-spatial resolution whole-brain MWF mapping within ∼20 min. Despite the subsequent significant advances in the inversion algorithm to derive MWF maps from steady-state MRI, the high-dimensional nature of such inversion does not permit further reduction of the acquisition time by data under-sampling. In this work, we present an unprecedented reduction in the computation (∼30 s) and the acquisition time (∼7 min) required for whole-brain high-resolution MWF mapping through a new Neural Network (NN)-based approach, named NN-Relaxometry of Extremely Under-SamplEd Data (NN-REUSED). Our analyses demonstrate virtually similar accuracy and precision in derived MWF values using NN-REUSED compared to results derived from the fully sampled reference method. The reduction in the acquisition and computation times represents a breakthrough toward clinically practical MWF mapping.

C-NODDI: a constrained NODDI model for axonal density and orientation determinations in cerebral white matter

Purpose

Neurite orientation dispersion and density imaging (NODDI) provides measures of neurite density and dispersion through computation of the neurite density index (NDI) and the orientation dispersion index (ODI). However, NODDI overestimates the cerebrospinal fluid water fraction in white matter (WM) and provides physiologically unrealistic high NDI values. Furthermore, derived NDI values are echo-time (TE)-dependent. In this work, we propose a modification of NODDI, named constrained NODDI (C-NODDI), for NDI and ODI mapping in WM.

Methods

Using NODDI and C-NODDI, we investigated age-related alterations in WM in a cohort of 58 cognitively unimpaired adults. Further, NDI values derived using NODDI or C-NODDI were correlated with the neurofilament light chain (NfL) concentration levels, a plasma biomarker of axonal degeneration. Finally, we investigated the TE dependence of NODDI or C-NODDI derived NDI and ODI.

Results

ODI derived values using both approaches were virtually identical, exhibiting constant trends with age. Further, our results indicated a quadratic relationship between NDI and age suggesting that axonal maturation continues until middle age followed by a decrease. This quadratic association was notably significant in several WM regions using C-NODDI, while limited to a few regions using NODDI. Further, C-NODDI-NDI values exhibited a stronger correlation with NfL concentration levels as compared to NODDI-NDI, with lower NDI values corresponding to higher levels of NfL. Finally, we confirmed the previous finding that NDI estimation using NODDI was dependent on TE, while NDI derived values using C-NODDI exhibited lower sensitivity to TE in WM.

Conclusion

C-NODDI provides a complementary method to NODDI for determination of NDI in white matter.

Lower Myelin Content Is Associated With Lower Gait Speed in Cognitively Unimpaired Adults

Mounting evidence indicates that abnormal gait speed predicts the progression of neurodegenerative diseases, including Alzheimer's disease. Understanding the relationship between white matter integrity, especially myelination, and motor function is crucial to the diagnosis and treatment of neurodegenerative diseases. We recruited 118 cognitively unimpaired adults across an extended age range of 22-94 years to examine associations between rapid or usual gait speeds and cerebral myelin content. Using our advanced multicomponent magnetic resonance relaxometry method, we measured myelin water fraction (MWF), a direct measure of myelin content, as well as longitudinal and transverse relaxation rates (R1 and R2), sensitive but nonspecific magnetic resonance imaging measures of myelin content. After adjusting for covariates and excluding 22 data sets due to cognitive impairments or artifacts, our results indicate that participants with higher rapid gait speed exhibited higher MWF, R1, and R2 values, that is, higher myelin content. These associations were statistically significant within several white matter brain regions, particularly the frontal and parietal lobes, splenium, anterior corona radiata, and superior fronto-occipital and longitudinal fasciculus. In contrast, we did not find any significant associations between usual gait speed and MWF, R1, or R2, which suggests that rapid gait speed may be a more sensitive marker of demyelination than usual gait speed. These findings advance our understanding on the implication of myelination in gait impairment among cognitively unimpaired adults, providing further evidence of the interconnection between white matter integrity and motor function.

Lower myelin content is associated with more rapid cognitive decline among cognitively unimpaired individuals

INTRODUCTION

The influence of myelination on longitudinal changes in cognitive performance remains unclear.

METHODS

For each participant (N = 123), longitudinal cognitive scores were calculated. Myelin content was probed using myelin water fraction (MWF) or longitudinal relaxation rate (R1 ); both are MRI measures sensitive to myelin, with MWF being specific.

RESULTS

Lower MWF was associated with steeper declines in executive function (p < .02 in all regions) and lower R1 was associated with steeper declines in verbal fluency (p < .03 in all regions). Additionally, lower R1 was associated with steeper declines in executive function (p < .02 in all regions) and memory (p < .04 in occipital and cerebral white matter) but did not survive Bonferroni correction.

DISCUSSION

We demonstrate significant relationships between myelin content and the rates of change in cognitive performance among cognitively normal individuals. These findings highlight the importance of myelin in cognitive functioning and suggest MWF and R1 as imaging biomarkers to predict cognitive changes.

Adult lifespan maturation and degeneration patterns in gray and white matter: A mean apparent propagator (MAP) MRI study

The relationship between brain microstructure and aging has been the subject of intense study, with diffusion MRI perhaps the most effective modality for elucidating these associations. Here, we used the mean apparent propagator (MAP)-MRI framework, which is suitable to characterize complex microstructure, to investigate age-related cerebral differences in a cohort of cognitively unimpaired participants and compared the results to those derived using diffusion tensor imaging. We studied MAP-MRI metrics, among them the non-Gaussianity (NG) and propagator anisotropy (PA), and established an opposing pattern in white matter of higher NG alongside lower PA among older adults, likely indicative of axonal degradation. In gray matter, however, these two indices were consistent with one another, and exhibited regional pattern heterogeneity compared to other microstructural parameters, which could indicate fewer neuronal projections across cortical layers along with an increased glial concentration. In addition, we report regional variations in the magnitude of age-related microstructural differences consistent with the posterior-anterior shift in aging paradigm. These results encourage further investigations in cognitive impairments and neurodegeneration.

Evidence of An Association Between Cerebral Blood Flow and Microstructural Integrity in Normative Aging Using a Holistic MRI Approach

BACKGROUND

Cerebral tissue integrity decline and cerebral blood flow (CBF) alteration are major aspects of motor and cognitive dysfunctions and neurodegeneration. However, little is known about the association between blood flow and brain microstructural integrity, especially in normal aging.

PURPOSE

To assess the association between CBF and cerebral microstructural integrity.

STUDY TYPE

Cross sectional.

POPULATION

A total of 94 cognitively unimpaired adults (mean age 50.7 years, age range between 22 and 88 years, 56 Men).

FIELD STRENGTH/SEQUENCE

A 3 T; pseudo-continuous arterial spin labeling (pCASL), diffusion tensor imaging (DTI), Bayesian Monte Carlo analysis of multicomponent driven equilibrium steady-state observation of T₁ and T₂ (BMC-mcDESPOT).

ASSESSMENT

Lobar associations between CBF derived from pCASL, and longitudinal relaxation rate (R₁ ), transverse relaxation rate (R₂ ) and myelin water fraction (MWF) derived from BMC-mcDESPOT, or radial diffusivity (RD), axial diffusivity (AxD), mean diffusivity (MD) and fractional anisotropy (FA) derived from DTI were assessed.

STATISTICAL TESTS

Multiple linear regression models were used using the mean region of interest (ROI) values for MWF, R₁ , R₂ , FA, MD, RD, or AxD as the dependent variable and CBF, age, age² , and sex as the independent variables. A two-sided P value of <0.05 defined statistical significance.

RESULTS

R₁ , R₂ , MWF, FA, MD, RD, and AxD parameters were associated with CBF in most of the cerebral regions evaluated. Specifically, higher CBF values were significantly associated with higher FA, MWF, R₁ and R₂ , or lower MD, RD and AxD values.

DATA CONCLUSION

These findings suggest that cerebral tissue microstructure may be impacted by global brain perfusion, adding further evidence to the intimate relationship between cerebral blood supply and cerebral tissue integrity.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 4.

Association of Cerebral Blood Flow With Longitudinal Changes in Cerebral Microstructural Integrity in the Coronary Artery Risk Development in Young Adults (CARDIA) Study

IMPORTANCE

Decreased cerebral tissue integrity and cerebral blood flow (CBF) are features of neurodegenerative diseases. Brain tissue maintenance is an energy-demanding process, making it particularly sensitive to hypoperfusion. However, little is known about the association between blood flow and brain microstructural integrity, including in normative aging.

OBJECTIVE

To assess associations between CBF and changes in cerebral tissue integrity in white matter and gray matter brain regions.

DESIGN, SETTING, AND PARTICIPANTS

In this longitudinal cohort study, magnetic resonance imaging was performed on 732 healthy adults from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective longitudinal study (baseline age of 18-30 years) that examined participants up to 8 times during 30 years (1985-1986 to 2015-2016). Cerebral blood flow was measured at baseline (year 25 of the CARDIA study), and changes in diffusion tensor indices of fractional anisotropy (FA) and mean diffusivity (MD), measures of microstructural tissue integrity, were measured at both baseline and after approximately 5 years of follow-up (year 30). Analyses were conducted from November 5, 2020, to January 29, 2022.

MAIN OUTCOMES AND MEASURES

Automated algorithms and linear mixed-effects statistical models were used to evaluate the associations between CBF at baseline and changes in FA or MD.

RESULTS

After exclusion of participants with missing or low-quality data, 654 at baseline (342 women; mean [SD] age, 50.3 [3.5] years) and 433 at follow-up (230 women; mean [SD] age, 55.1 [3.5] years) were scanned for CBF or FA and MD imaging. In the baseline cohort, 247 participants were Black (37.8%) and 394 were White (60.2%); in the follow-up cohort, 156 were Black (36.0%) and 277 were White (64.0%). Cross-sectionally, FA and MD were associated with CBF in most regions evaluated, with lower CBF values associated with lower FA or higher MD values, including the frontal white matter lobes (for CBF and MD: mean [SE] β = -1.4 [0.5] × 10-6; for CBF and FA: mean [SE] β = 2.9 [1.0] × 10-4) and the parietal white matter lobes (for CBF and MD: mean [SE] β = -2.4 [0.6] × 10-6; for CBF and FA: mean [SE] β = 4.4 [1.1] × 10-4). Lower CBF values at baseline were also significantly associated with steeper regional decreases in FA or increases in MD in most brain regions investigated, including the frontal (for CBF and MD: mean [SE] β = -1.1 [0.6] × 10-6; for CBF and FA: mean [SE] β = 2.9 [1.0] × 10-4) and parietal lobes (for CBF and MD: mean [SE] β = -1.5 [0.7] × 10-6; for CBF and FA: mean [SE] β = 4.4 [1.1] × 10-4).

CONCLUSIONS AND RELEVANCE

Results of this longitudinal cohort study of the association between CBF and diffusion tensor imaging metrics suggest that blood flow may be significantly associated with brain tissue microstructure. This work may lay the foundation for investigations to clarify the nature of early brain damage in neurodegeneration. Such studies may lead to new neuroimaging biomarkers of brain microstructure and function for disease progression.

Insights into human cerebral white matter maturation and degeneration across the adult lifespan

White matter (WM) microstructural properties change across the adult lifespan and with neuronal diseases. Understanding microstructural changes due to aging is paramount to distinguish them from neuropathological changes. Conducted on a large cohort of 147 cognitively unimpaired subjects, spanning a wide age range of 21 to 94 years, our study evaluated sex- and age-related differences in WM microstructure. Specifically, we used diffusion tensor imaging (DTI) magnetic resonance imaging (MRI) indices, sensitive measures of myelin and axonal density in WM, and myelin water fraction (MWF), a measure of the fraction of the signal of water trapped within the myelin sheets, to probe these differences. Furthermore, we examined regional correlations between MWF and DTI indices to evaluate whether the DTI metrics provide information complementary to MWF. While sexual dimorphism was, overall, nonsignificant, we observed region-dependent differences in MWF, that is, myelin content, and axonal density with age and found that both exhibit nonlinear, but distinct, associations with age. Furthermore, DTI indices were moderately correlated with MWF, indicating their good sensitivity to myelin content as well as to other constituents of WM tissue such as axonal density. The microstructural differences captured by our MRI metrics, along with their weak to moderate associations with MWF, strongly indicate the potential value of combining these outcome measures in a multiparametric approach. Furthermore, our results support the last-in-first-out and the gain-predicts-loss hypotheses of WM maturation and degeneration. Indeed, our results indicate that the posterior WM regions are spared from neurodegeneration as compared to anterior regions, while WM myelination follows a temporally symmetric time course across the adult life span.

Differential associations between apolipoprotein E alleles and cerebral myelin content in normative aging

Mounting evidence indicates that myelin breakdown may represent an early phenomenon in neurodegeneration, including Alzheimer's disease (AD). Understanding the factors influencing myelin synthesis and breakdown will be essential for the development and evaluation of therapeutic interventions. In this work, we assessed associations between genetic variance in apolipoprotein E (APOE) and cerebral myelin content. Quantitative magnetic resonance imaging (qMRI) was performed on a cohort of 92 cognitively unimpaired adults ranging in age from 24 to 94 years. We measured whole-brain myelin water fraction (MWF), a direct measure of myelin content, as well as longitudinal and transverse relaxation rates (R₁ and R₂), sensitive measures of myelin content, in carriers of the APOE ε4 or APOE ε2 alleles and individuals with the ε33 genotype. Automated brain mapping algorithms and statistical models were used to evaluate the relationships between MWF or relaxation rates and APOE isoforms, accounting for confounding variables including age, sex, and race, in several cerebral structures. Our results indicate that carriers of APOE ε2 exhibited significantly higher myelin content, that is, higher MWF, R₁ or R₂ values, in most brain regions investigated as compared to noncarriers, while ε4 carriers exhibited trends toward lower myelin content compared to noncarriers. Finally, all qMRI metrics exhibited quadratic, inverted U-shape, associations with age; attributed to the development of myelination from young to middle age followed by progressive loss of myelin afterwards. Sex and race effects on myelination were, overall, nonsignificant. These findings suggest that individual genetic background may influence cerebral myelin maintenance. Although preliminary, this work lays the foundation for further investigations to clarify the relationship between APOE genotype and myelination, which may suggest potential targets in treatment or prevention of AD.

Cerebral aggregate g-ratio mapping using magnetic resonance relaxometry and diffusion tensor imaging to investigate sex and age-related differences in white matter microstructure

Axonal demyelination is a cardinal feature of aging and age-related diseases. The g-ratio, mathematically defined as the inner-to-outer diameter of a myelinated axon, is used as a structural index of optimal axonal myelination and has been shown to represent a sensitive imaging biomarker of microstructural integrity. Several magnetic resonance imaging (MRI) methods for whole-brain mapping of aggregate g-ratio have been introduced. Computation of the aggerate g-ratio requires estimates of the myelin volume fraction (MVF) and the axonal volume fraction (AVF). While accurate determinations of MVF and AVF can be obtained through multicomponent relaxometry or diffusion analyses, respectively, these methods require lengthy acquisition times making their implementation challenging in a clinical context. Therefore, any attempt to overcome this drawback is needed. Expanding on our previous work, we introduced a new MRI method for whole-brain mapping of aggregate g-ratio. This new approach is based on the use of a single-shell diffusion for AVF determination, reducing the acquisition time by approximately ~10 min from our recently introduced approach, while offering the possibility to investigate g-ratio differences in previous studies with existing data for MVF mapping and single-shell diffusion data for AVF mapping. Our comparison analysis indicates that our newly derived aggregate g-ratio values were similar to those derived from our previous method, which requires a longer acquisition time. Further, in agreement with our previous observations, we found quadratic U-shaped relationships between aggregate g-ratio and age in this much larger study cohort. However, our results show that sexual dimorphism in g-ratio was not significant in any brain region investigated.

Characterization of Age-Related Differences in the Human Choroid Plexus Volume, Microstructural Integrity, and Blood Perfusion Using Multiparameter Magnetic Resonance Imaging

The choroid plexus (CP) is an important cerebral structure involved in cerebrospinal fluid production and transport of solutes into the brain. Recent studies have uncovered the involvement of the CP in neurological disorders such as Alzheimer's disease and multiple sclerosis. However, our understanding of human age-related microstructural and functional changes in the CP with aging and neuropathology is limited. In this cross-sectional study, we investigated age and sex differences in the CP structure and function using advanced quantitative magnetic resonance imaging methodology in a large cohort (n = 155) of cognitively unimpaired individuals over a wide age range between 21 and 94 years. Our analysis included volumetric measurements, relaxometry measures (T 1 and T 2), diffusion tensor imaging (DTI) measures of fractional anisotropy (FA) and mean diffusivity (MD), as well as measures of cerebral blood flow (CBF). Our results revealed that CP volume was increasing with advancing age. We conjecture that this novel observation is likely attributed to alterations in the CP microstructure or function as well as to ventriculomegaly. Indeed, we also found that CBF was lower with advanced age, while, consistent with previous studies, T 1, T 2 and MD were higher, and FA was lower with advanced age. We attribute these functional and microstructural differences to a deteriorated CP structural integrity with aging. Furthermore, our relaxometry and DTI measures were found to be associated with differences in blood perfusion revealing lower microstructural integrity with lower CBF. Finally, in agreement with literature, sex-related differences in MD and CBF were statistically significant. This work lays the foundation for ongoing investigation of the involvement of CP in neurodegeneration.

Investigation of the association between cerebral iron content and myelin content in normative aging using quantitative magnetic resonance neuroimaging

Myelin loss and iron accumulation are cardinal features of aging and various neurodegenerative diseases. Oligodendrocytes incorporate iron as a metabolic substrate for myelin synthesis and maintenance. An emerging hypothesis in Alzheimer’s disease research suggests that myelin breakdown releases substantial stores of iron that may accumulate, leading to further myelin breakdown and neurodegeneration. We assessed associations between iron content and myelin content in critical brain regions using quantitative magnetic resonance imaging (MRI) on a cohort of cognitively unimpaired adults ranging in age from 21 to 94 years. We measured whole-brain myelin water fraction (MWF), a surrogate of myelin content, using multicomponent relaxometry, and whole-brain iron content using susceptibility weighted imaging in all individuals. MWF was negatively associated with iron content in most brain regions evaluated indicating that lower myelin content corresponds to higher iron content. Moreover, iron content was significantly higher with advanced age in most structures, with men exhibiting a trend towards higher iron content as compared to women. Finally, relationship between MWF and age, in all brain regions investigated, suggests that brain myelination continues until middle age, followed by degeneration at older ages. This work establishes a foundation for further investigations of the etiology and sequelae of myelin breakdown and iron accumulation in neurodegeneration and may lead to new imaging markers for disease progression and treatment.

Mutant p53: a novel target for the treatment of patients with triple-negative breast cancer?

The identification and validation of a targeted therapy for patients with triple-negative breast cancer (TNBC) is currently one of the most urgent needs in breast cancer therapeutics. One of the key reasons for the failure to develop a new therapy for this subgroup of breast cancer patients has been the difficulty in identifying a highly prevalent, targetable molecular alteration in these tumors. Recently however, the p53 gene was found to be mutated in approximately 80% of basal/TNBC, raising the possibility that targeting the mutant p53 protein product might be a new approach for the treatment of this form of breast cancer. In this study, we investigated the anti-cancer activity of PRIMA-1 and PRIMA-1^MET (APR-246), two compounds which were previously reported to reactivate mutant p53 and convert it to a form with wild-type (WT) properties. Using a panel of 18 breast cancer cell lines and 2 immortalized breast cell lines, inhibition of proliferation by PRIMA-1 and PRIMA-1^MET was found to be cell-line dependent, but independent of cell line molecular subtype. Although response was independent of molecular subtype, p53 mutated cell lines were significantly more sensitive to PRIMA-1^MET than p53 WT cells (p = 0.029). Furthermore, response (measured as IC₅₀ value) correlated significantly with p53 protein level as measured by ELISA (p = 0.0089, r=-0.57, n = 19). In addition to inhibiting cell proliferation, PRIMA-1^MET induced apoptosis and inhibited migration in a p53 mutant-dependent manner. Based on our data, we conclude that targeting mutant p53 with PRIMA-1^MET is a potential new approach for treating p53-mutated breast cancer, including the subgroup with triple-negative (TN) disease.

Parental physical and lifestyle factors and their association with newborn body composition

OBJECTIVE

To investigate the parental physical and lifestyle determinants of newborn body composition.

DESIGN

Prospective cohort study.

SETTING

Cork University Maternity Hospital, a tertiary referral hospital in Cork, Ireland.

POPULATION

All babies were recruited as part of a prospective birth cohort, Babies After

SCOPE

Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE). These babies were recruited from women who had participated in the Screening of Pregnancy Endpoints (SCOPE) study Ireland, a prospective, multicentre cohort study

METHODS

Multivariate linear regression was used to analyse the effect of a range of maternal and paternal physical and lifestyle features on neonatal body fat percentage (BF%).

MAIN OUTCOME MEASURES

Neonatal BF%. Neonatal adiposity was assessed within 48 hours of birth using air displacement plethysmography (PEAPOD(®) ).

RESULTS

In all, 1243 infants were enrolled in the study. Increasing maternal body mass index (adjusted mean difference 0.09; 0.04, 0.15) and waist height ratio (adjusted mean difference 6.59; 0.27, 12.92) were significantly associated with increased neonatal BF%. In contrast, maternal smoking was associated with reduced neonatal BF% compared with non smokers (adjusted mean difference -0.55; -1.07, -0.03). Infant sex significantly altered neonatal BF%, with female infants having higher neonatal BF% compared with male infants (adjusted mean difference 1.98; 1.54, 2.53). No association was observed between paternal body mass index (BMI), paternal age or paternal smoking and neonatal BF%.

CONCLUSIONS

Maternal smoking, BMI, waist height ratio and infant sex were associated with altered BF%.

TWEETABLE ABSTRACT

Maternal smoking, BMI, waist height ratio and infant sex are associated with altered neonatal body fat percentage.

Recommended dietary intakes for vitamin D: Where do they come from, what do they achieve and how can we meet them?

There is substantial evidence that the prevalence of vitamin D deficiency is high across Europe, particularly, but not exclusively, among those resident at Northerly latitudes. This has significant implications for human health throughout the lifecycle and impacts upon healthy growth and development and successful ageing for current and possibly future generations. In recent years, there have been several important reports from North America and Europe in relation to dietary reference values (DRVs) for vitamin D. These may be of enormous value from a public health perspective in terms of preventing vitamin D deficiency and promoting adequate vitamin D status in the population. In this concise review, we provide a brief summary of current DRVs for vitamin D, their background and their application to vitamin D deficiency prevention. The review also provides some brief guidance with respect to applying the DRVs in a clinical nutrition setting. In addition, the review illustrates how current dietary intakes of most populations, young and adult, are well short of the newly established DRVs. Accordingly, the review highlights potential food-based or dietary strategies for increasing the distribution of vitamin D intake in the population with the aim of preventing vitamin D deficiency. Finally, despite the explosion in scientific research in vitamin D and health, there are many fundamental gaps in the field of vitamin D from the public health perspective. The impact of these knowledge gaps on current DRVs for vitamin D is highlighted, as are some future developments that may help address these gaps.

Intimate partner violence during pregnancy: victim or perpetrator? Does it make a difference?

OBJECTIVES

To differentiate between forms of intimate partner violence (IPV) (victim only, perpetrator only, or participating in reciprocal violence) and examine risk profiles and pregnancy outcomes.

DESIGN

Prospective.

SETTING

Washington, DC, July 2001 to October 2003.

SAMPLE

A total of 1044 high-risk African-American pregnant women who participated in a randomised controlled trial to address IPV, depression, smoking and environmental tobacco smoke exposure.

METHODS

Multivariable linear and logistic regression.

MAIN OUTCOME MEASURES

Low and very low birthweight, preterm and very preterm birth.

RESULTS

Five percent of women were victims only, 12% were perpetrators only, 27% participated in reciprocal violence and 55% reported no IPV. Women reporting reciprocal violence in the past year were more likely to drink, use illicit drugs and experience environmental tobacco smoke exposure and were less likely to be very happy about their pregnancies. Women reporting any type of IPV were more likely to be depressed than those reporting no IPV. Women experiencing reciprocal violence reported the highest levels of depression. Women who were victims of IPV were more likely to give birth prematurely and deliver low-birthweight and very-low-birthweight infants.

CONCLUSIONS

We conclude that women were at highest risk for pregnancy risk factors when they participated in reciprocal violence and so might be at higher risk for long-term consequences, but women who were victims of IPV were more likely to show proximal negative outcomes like preterm birth and low birthweight infants. Different types of interventions may be needed for these two forms of IPV.

Gestational diabetes, pre-pregnancy obesity and pregnancy weight gain in relation to excess fetal growth: variations by race/ethnicity

AIMS/HYPOTHESIS

The escalating rate of childhood obesity is a public health concern worldwide, with children in certain ethnic groups being disproportionately affected. Our objective was to examine the joint effects of pre-pregnancy adiposity, pregnancy weight gain and gestational diabetes (GDM) in relation to excess fetal growth and to identify susceptible races or ethnic populations.

METHODS

The risk for delivery of a large-for-gestational-age (LGA) infant, specific to race and fetal sex, was evaluated in 105,985 pregnancies in the Consortium on Safe Labor from 2002-2008. Generalised estimating equations were used to estimate the risk for delivery of LGA infants. Joint effects were employed to evaluate the interplay of three risk factors. Models were stratified by racial group considering one, two or three factors (i.e. pre-pregnancy adiposity, pregnancy weight gain and GDM, with 0 factors as the reference group).

RESULTS

Greater pre-pregnancy adiposity, pregnancy weight gain and GDM were independently associated with increased risk of giving birth to an LGA infant across all races (except GDM among non-Hispanic whites), in both underweight and normal-weight women. Among non-Hispanic white, non-Hispanic black and Hispanic women, the three-factor joint effect was associated with substantially increased odds of LGA (OR [95% CI] 11.27 [8.40, 15.11], 7.09 [4.81, 10.45] and 10.19 [6.84, 15.19], respectively). However, for Asian women the joint effect of all three factors (OR [95% CI] 5.14 [2.11, 12.50]) was approximately the same as any of the two factors.

CONCLUSIONS/INTERPRETATION

GDM, pre-pregnancy obesity and excessive pregnancy weight gain were jointly associated with elevated risk of giving birth to an LGA infant and the effects varied by race. This suggests that those involved in public health efforts aimed at preventing LGA deliveries should consider variations in racial groups when devising effective strategies.

Proceedings of the Rank Forum on Vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of 'optimal' concentration of serum 25(OH)D needs to define 'optimal' with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

Vitamin D status and parathyroid hormone relationship in adolescents and its association with bone health parameters: analysis of the Northern Ireland Young Heart's Project

In girls, a plateau in parathyroid hormone (PTH) was observed at a 25-hydroxyvitamin D (25(OH)D) concentration of approximately 60 nmol/l. In boys, there was no plateau in PTH concentrations as 25(OH)D concentration increased. A 25(OH)D threshold of 60 nmol/l appears to have implications for bone health outcomes in both girls and boys.

INTRODUCTION

Our objective was to investigate if there is a threshold 25(OH)D concentration where a plateau in PTH concentration is evident and to examine the impact of this relationship on bone mineral density (BMD) and bone turnover in a representative sample of adolescents.

METHODS

We conducted a cross-sectional analysis among 1,015 Northern Irish adolescents aged 12 and 15 years. Serum 25(OH)D, PTH, osteocalcin, type 1 collagen cross-linked C-telopeptide (CTx), and BMD of the nondominant forearm and heel were measured. Nonlinear regression analysis was used to model the association between 25(OH)D and PTH.

RESULTS

In girls, a plateau in PTH was observed at a 25(OH)D concentration of approximately 60 nmol/l (PTH = 47.146 + 370.314 x exp((-0.092 x 25(OH)D))) while no plateau in PTH was observed in boys (PTH = 42.144 + 56.366 x exp((-0.022 x 25(OH)D))). Subjects with 25(OH)D levels <60 nmol/l had significantly higher osteocalcin concentrations (P < 0.05) compared with those who had >or=60 nmol/l, while no significant (P > 0.05) differences were noted for CTx concentrations. In girls only, nondominant forearm BMD but not heel BMD was significantly higher (P = 0.046) in those with 25(OH)D concentrations >or= 60 nmol/l.

CONCLUSIONS

Serum 25(OH)D levels above 60 nmol/l in Northern Irish adolescent girls prevent an increase in serum PTH levels and maintaining 25(OH)D >60 nmol/l in both girls and boys may lead to improved bone health outcomes.

Prevalence of suboptimal vitamin D status during pregnancy

Low maternal vitamin D status has been associated with reduced intrauterine long bone growth and shorter gestation, decreased birth weight, as well as reduced childhood bone-mineral accrual. Despite data from other countries indicating low maternal vitamin D status is common during pregnancy, there is a dearth of information about vitamin D status during pregnancy in the Irish female population. Therefore, we prospectively assessed vitamin D nutritive status and the prevalence of suboptimal vitamin D status in a cohort of Irish pregnant women. The mean (SD) daily intake of vitamin D by the group of pregnant women was 3.6 (1.9) microg/day. None of the women achieved the recommended daily vitamin D intake value for Irish pregnant women (10 microg/day). Taking all three trimesters collectively, 14.3-23.7% and 34.3-52.6% of Irish women had vitamin D deficiency (serum 25 (OH) D <25 nmol/l) and insufficiency (serum 25 (OH) D 25-50 nmol/l), respectively during pregnancy. Both the levels of serum 25 (OH) D and the prevalence of vitamin D deficiency/adequacy were dramatically influenced by season, with status being lowest during the extended winter period and best during the extended summer period. These findings show that inadequate vitamin D status is common in Irish pregnant women.

Beneficial effects of long-chain n-3 fatty acids included in an energy-restricted diet on insulin resistance in overweight and obese European young adults

AIMS/HYPOTHESIS

Epidemiological research indicates that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) improve insulin resistance. The aim of this study was to investigate the effects of seafood consumption on insulin resistance in overweight participants during energy restriction.

METHODS

In this 8 week dietary intervention, 324 participants (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) were randomised by computer to one of four energy-restricted diets (-30E%) of identical macronutrient composition but different LC n-3 PUFA content: control (n = 80; no seafood; single-blinded); lean fish (n = 80; 150 g cod, three times/week); fatty fish (n = 84; 150 g salmon, three times/week); (4) fish oil (n = 80; daily docosahexaenoic/eicosapentaenoic acid capsules, no other seafood; single-blinded). Fasting glucose, insulin, adiponectin, plasma triacylglycerol and fatty acids in erythrocyte membrane were measured at baseline and endpoint. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Linear models with fixed effects and covariates were used to investigate the effects of seafood consumption on fasting insulin and HOMA-IR at endpoint in comparison with the control group.

RESULTS

Of the participants, 278 (86%) completed the intervention. Fish oil intake was a significant predictor of fasting insulin and insulin resistance after 8 weeks, and this finding remained significant even after including weight loss, triacylglycerol reduction, increased LC n-3 PUFA in membranes or adiponectin changes as covariates in the statistical analysis. Weight loss was also a significant predictor of improvements.

CONCLUSIONS/INTERPRETATION

LC n-3 PUFA consumption during energy reduction exerts positive effects on insulin resistance in young overweight individuals, independently from changes in body weight, triacylglycerol, erythrocyte membrane or adiponectin.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00315770.

Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content

OBJECTIVE

To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults.

DESIGN

Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood); (2) lean fish (3 x 150 g portions of cod/week); (3) fatty fish (3 x 150 g portions of salmon/week); (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups, were single-blinded.

SUBJECTS

A total of 324 men and women aged 20-40 years, BMI 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland.

MEASUREMENTS

Anthropometric data were collected at baseline, midpoint and endpoint. Confounding factors were accounted for, with linear models, for repeated measures with two-way interactions. The most important interactions for weight loss were (diet x energy intake), (gender x diet) and (gender x initial-weight).

RESULTS

An average man in the study (95 kg at baseline receiving 1600 kcal/day) was estimated to lose 3.55 kg (95% CI, 3.14-3.97) (1); 4.35 kg (95% CI, 3.94-4.75) (2); 4.50 kg (95% CI, 4.13-4.87) (3) and 4.96 kg (95% CI, 4.53-5.40) on diet (4) in 4 weeks, from baseline to midpoint. The weight-loss from midpoint to endpoint was 0.45 (0.41-0.49) times the observed weight loss from baseline to midpoint. The diets did not differ in their effect on weight loss in women. Changes in measures of body composition were in line with changes in body weight.

CONCLUSION

In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet resulted in approximately 1 kg more weight loss after 4 weeks, than did a similar diet without seafood or supplement of marine origin. The addition of seafood to a nutritionally balanced energy-restricted diet may boost weight loss.

An examination of the influence of eating location on the diets of Irish children

OBJECTIVES

To examine the influence of eating location on the quality of the diets of Irish children and to compare intakes at home with intakes at other people's homes and intakes outside the home, and to compare intakes at various locations outside the home.

DESIGN

Food intake was measured using a 7-day weighed diary in 594 children from the Republic of Ireland (aged 5-12 years). Details of where the food was prepared or obtained were also recorded.

RESULTS

Eighty-nine per cent of all eating occasions occurred at home; < 6% occurred at both other people's homes and outside the home (takeaway, restaurant, shop, other). The percentage of food energy from fat was above the recommended 35% at other people's homes and outside the home, specifically at takeaways and restaurants. Fibre and micronutrient intakes (per 10 MJ) were significantly higher at home than at the other locations (P < 0.05). Within the 'out' locations, fibre and micronutrient intakes were generally higher at restaurants and lower at shops. High consumers of foods outside the home had a statistically significant, but relatively small decline in nutrient intakes compared with non- or low consumers. Chips and processed potatoes, meat products, savouries, sugars and confectionery, and savoury snacks made the greatest contribution to foods consumed outside the home.

CONCLUSIONS

The main focus of nutrition policies to improve the diets of Irish children should be the home environment rather than the food service sector. However, guidelines could call for better food choices outside the home to improve nutrient intakes.

Associations between daily food intake and excess adiposity in Irish adults: towards the development of food-based dietary guidelines for reducing the prevalence of overweight and obesity

BACKGROUND

The prevalence of obesity has nearly doubled in Ireland since 1990 and over half of the population has a large waist circumference (WC). No food-based, dietary guidelines exist in Ireland for a reduction in the prevalence of body fat or obesity.

OBJECTIVE

To examine the association between daily food intake and categories of body mass index and WC for the development of dietary guidelines to combat obesity.

DESIGN

Cross-sectional study of a random representative sample of 1379 adults aged 18-64 years from Northern Ireland and the Republic of Ireland.

MEASUREMENTS

Weight, height and WC were measured according to standard procedures. Diet was assessed using a 7-day food diary from which 28 food groups were generated and entered into logistic regression analysis.

RESULTS

Higher mean daily consumption of most of the 28 food groups was associated with an increased likelihood of being classified as obese or at waist action level 2, compared to normal weight and normal WC. The strongest associations were found for savoury snacks, butter and full fat spreads. Contrary to popular opinion, not one individual food group but rather a combination of many foods was associated with excess adiposity.

CONCLUSIONS

Body mass index and WC in adults are strongly influenced by the amount of food consumed. Public health policies for a reduction in body fat and obesity may be more effective if the emphasis is placed on a reduction of food and beverages consumed as opposed to the traditional dietary recommendations for macronutrients.

The importance of composite foods for estimates of vegetable and fruit intakes

Objective:

To evaluate the contribution of composite foods to vegetable and fruit intakes in Irish adults and to compliance with dietary guidelines for vegetable and fruit intake.

Design:

Data were analysed from the North/South Ireland Food Consumption Survey of 18–64-year-old adults (n= 1379; 662 men, 717 women), which used a 7-day food diary to estimate food intake.

Results:

The mean intake of vegetables (excluding potatoes) was 140g day−1(men 149g day−1; women 132g day−1), of fruit was 136 g day−1(men 133g day−1; women 140 g day−1) and of potatoes was 227 g day−1(men 296g day−1; women 163 g day−1). The mean daily intakes of vegetables, fruit and potatoes from composite foods were 37 g (26%), 6 g (5%) and 17 g (7%), respectively. The mean intake of vegetables from composite foods was unrelated to age or gender, but increased with increasing social class and level of education attained. The proportions of men and women meeting the recommendation for ≥400g day−1(5 servings of 80 g per day) of vegetables and fruit were 21% (15% excluding composite foods) and 19% (12% excluding composite foods), respectively. Compliance with the dietary recommendation decreased with decreasing levels of educational attainment and social class.

Conclusion:

Intakes of vegetables and fruit are low compared with current dietary recommendations, particularly in those of lower levels of educational attainment and social class. Composite foods are an important source of vegetables (less importantly of fruit) and should be included when estimating vegetable intakes. Failure to do so may result in bias in estimates of intake and of compliance with dietary guidelines for population groups, as well as misclassification of individuals by level of intake.

Prevalence of overweight and obesity in Irish school children, using four different definitions

OBJECTIVE

To determine the prevalence of overweight and obesity in Irish children using four different weight-for-height methods and to examine secular trends from previous national data.

DESIGN

A cross-sectional survey. Weight and height were measured according to standard procedures and used to determine the prevalence of overweight and obesity using four weight-for-height methods of assessment, actual relative weight, the Centers for Disease Control and Prevention body mass index (BMI) for age charts for boys and girls, the BMI reference curves for the UK 1990 and the International Obesity Task Force age- and sex-specific BMI cutoffs.

SETTING

The survey was carried out between 2003 and 2004 in the Republic of Ireland.

SUBJECTS

Random representative sample of 596 children aged 5-12 years.

RESULTS

The prevalence of overweight and obesity in Irish children is high, but varies considerably with each method. The prevalence of obesity in boys ranged from 4.1 to 11.2 % and in girls from 9.3 to 16.3%. Between 1990 and 2005, depending on the method used, there was a two-to-fourfold increase in obesity in children aged 8-12 years.

CONCLUSION

It is evident given the variation displayed in the prevalence of obesity when using the different methods, that there is a discernible need for a single definition to identify the obese child in Ireland. The findings show a high prevalence of overweight and obesity in Irish school children and the increase in the prevalence of obesity over the last 15 years highlights this growing public health issue.

Vitamin D intake and status in Irish elderly women and adolescent girls

AIM

To assess vitamin D status during summer and winter in Irish girls and elderly women, and to estimate vitamin D intake in these two age-groups.

METHODS

Ambulatory free-living, elderly Irish women (aged 70-76 years; n = 43) and girls (aged 11-13 years; n = 17) were recruited. Fasting serums were collected during August/ September 2002 and February/March 2003 and analysed for 25 (OH) D by HPLC.

RESULTS

Mean daily intakes of vitamin D were 4.6 microg and 2.1 microg in elderly women and girls, respectively. Serum 25 (OH) D was significantly lower (P<0.001) during winter than summer in both age-groups. Eight (20%) and one (during late summer) and sixteen (37.2%) and eight (47%) (during late winter) of the elderly women and girls, respectively, had inadequate vitamin D status (serum 25 (OH) D <40 nmol/l).

CONCLUSION

Inadequate vitamin D status during winter time is quite common in elderly women and adolescent girls in Ireland.

Prevalence of suboptimal vitamin D status in young, adult and elderly Irish subjects

With the exception of the elderly, there is a dearth of information about the vitamin D status of Irish subjects. Therefore, we assessed the prevalence of suboptimal vitamin D status in a number of age-groups within the Irish population (including females aged, 11-13 years, 23-50 years, 51-69 years, and 70-75 years; and males, aged 20-64 years) during late-winter and late-summer. In females, depending on the age-group studied, between 4 and 19% and between 34 and 85% had an inadequate serum 25 (OH) D level (<50 nmol/l) during late-summer and late-winter, respectively. During late-summer, there was a marked absence of severe and moderate vitamin D deficiency in all subjects, while, 7% of men and, depending on the age-group studied, between 4 and 19% of females had mild vitamin D deficiency. During late-winter, none of the subjects had severe vitamin D deficiency. While none of the men had moderate vitamin D deficiency, 33% of men had mild vitamin D deficiency. In females, depending on the age-group studied, between 32 to 55% of females had mild vitamin D deficiency, and between 2 to 30% of females had moderate vitamin D deficiency, during late-winter. These findings show that inadequate vitamin D status is quite common in healthy Irish subjects, especially and notably so in young girls and more elderly women.

Psychosocial difficulties, deprivation and cancer: three questionnaire studies involving 609 cancer patients

The aim of the study is to investigate associations between deprivation and self-reported social difficulties and psychological distress in cancer patients. A total of 304 men and 305 women (age range 18-88 years) with a range of cancer diagnoses and living in a socially diverse region (Carstairs and Morris index) completed the Hospital Anxiety and Depression Scale and the Social Difficulties Inventory. Univariate analyses of variance revealed statistically significant differences in reported social difficulties between groups (F (67, 576)=2.4, P<0.0001) with stage of disease (F (5, 576)=7.6, P<0.0001), age (F (2, 576)=4.8, P=0.009) and to a lesser extent deprivation (F (1, 576)=4.0, P=0.048) making significant contributions. Significantly more social difficulties were reported by less affluent patients with locally recurrent disease or 'survivors'. No other interactions were found. Significant differences in levels of reported psychological distress were found between groups (F (67, 575)=1.723, P=0.001) for stage of disease, sex and deprivation but no interactions observed. In conclusion, deprivation is associated with reported psychological distress and, to a lesser extent, social difficulties. Patients at particular risk cannot be identified with confidence by socio-demographic and clinical means supporting the recommendation from National Institute for Clinical Excellence for provision of psychosocial assessment for individual cancer patients.

Development and evaluation of an instrument to assess social difficulties in routine oncology practice

PURPOSE

To develop and preliminarily evaluate a Social Difficulties Inventory (SDI) for use in oncology practice.

METHODS

Item generation from patients (n = 96), staff (n = 49) and the literature. Questions constructed and pre-tested (n = 42) resulting in a 22-item questionnaire. Psychometric evaluation (n = 271) assessed frequency of endorsement, factor structure, summated scales and construct validity followed by randomisation to criterion validity or test-retest arms.

RESULTS

Items met preset frequency of endorsement criteria. Factor analysis revealed a four-factor structure, three clearly definable, (1) Physical ability, (2) Providing for the family and (3) Contact with others, explaining 45.8% variance. Summated scales developed from these demonstrated good reliability (Cronbach's alpha > 0.7) and were used to test and confirmed construct validity. Several comparators from the Life Events and Difficulties Schedule (LEDS) and Cancer Rehabilitation Evaluation System Short Form (CARES-SF) tested criterion validity and majority agreements were moderate to good. Test-retest reliability was good with most kappa values > 0.6. One item was eliminated resulting in a 21-item questionnaire.

CONCLUSION

The SDI is relevant and easy to understand. Initial psychometric evaluation was encouraging. Ongoing work to evaluate the clinical meaning and utility of the instrument and to examine the relationships between SDI scores and clinical outcomes will provide guidance about its usefulness as an assessment tool in routine oncology practice.

Seasonality of vitamin D status and bone turnover in patients with Crohn's disease

BACKGROUND

While winter-time vitamin D deficiency has been well-documented in Crohn's disease patients, less is known about vitamin D status during summertime and whether a seasonal variation exists in bone turnover.

AIMS

To compare vitamin D status and bone turnover markers in Crohn's disease patients with age- and sex-matched controls during late-summer and late-winter.

SUBJECTS

Crohn's disease patients (n = 44; mean age 36.9 years, currently in remission) and matched controls (n = 44) were recruited from Cork University Hospital and Cork City area, respectively.

METHODS

Bloods were analysed for 25-hydroxyvitamin D, parathyroid hormone, bone-specific alkaline phosphatase, osteocalcin and urine analysed for N-telopeptides of type 1 collagen.

RESULTS

Serum 25-hydroxyvitamin D concentrations were significantly (P < 0.003) lower in Crohn's disease patients than in control subjects during both seasons. In Crohn's disease patients, serum 25-hydroxyvitamin D concentrations were lower (P < 0.0001) whereas serum parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase and urinary N-telopeptides of type 1 collagen levels were higher (P < 0.001) during late-winter than late-summer.

CONCLUSION

There were notable seasonal variations in vitamin D status and bone turnover markers in Crohn's disease patients. The impact of winter decline in vitamin D status and increase in bone turnover on long-term risk of osteopenia/osteoporosis in Crohn's disease patients is unclear.

Teenage girls and elderly women living in northern Europe have low winter vitamin D status

OBJECTIVE

To determine the vitamin D status (serum 25-hydroxyvitamin D; S-25OHD) in adolescent girls and elderly community-dwelling women living in four countries of northern Europe and to explain differences in S-25OHD concentrations between and within the countries.

DESIGN

A cross-sectional observational study conducted in a standardised way during February-March. S-25OHD was analysed by high-performance liquid chromatography. Vitamin D and calcium intake was calculated using a standardised food composition database.

SETTING

Denmark, Finland, Ireland, and Poland.

SUBJECTS

A total of 199 girls (mean (s.d.) age 12.6 (0.5) y) and 221 women (mean (s.d.) age 71.8 (1.4) y).

RESULTS

The median (inter quartiles) concentration of S-25OHD was 29.4 (20.3, 38.3) nmol/l for the girls and 40.7 (28.0, 54.2) nmol/l for the women. S-25OHD below 25 nmol/l was found in 37% of the girls and 17% of the women, and S-25OHD below 50 nmol/l was found in 92% of the girls and 37% of the women. Positive significant determinants for S-25OHD in girls were use of vitamin D supplements, and in women sun habits, dietary vitamin D intake, use of vitamin D and calcium supplements. Body mass index and smoking were negative determinants in women. For women predictors could explain the differences between countries (P(country) = 0.09, R(2) = 0.39), but for girls the difference remained significant even after including predictors (P(country) = 0.03, R(2) = 0.15).

CONCLUSION

Vitamin D status is low in northern Europe during winter. More than one-third of the adolescent girls have vitamin D status below 25 nmol/l and almost all are below 50 nmol/l. Two-thirds of the elderly community-dwelling women have vitamin D status below 50 nmol/l. Use of vitamin D supplements is a significant positive determinant for S-25OHD for both girls and women (P = 0.001).

SPONSORSHIP

The European Fifth Framework Programme (Contract No. QLK1-CT-2000-00623).