Multi-ethnic Population-based Cohort Study Research Articles

The impact of recommending iron supplements to women with depleted iron stores in early pregnancy on use of supplements, and factors associated with changes in iron status from early pregnancy to postpartum in a multi-ethnic population-based cohort

BackgroundWe aimed to evaluate the impact of recommending supplementation to pregnant women with serum ferritin (SF) < 20 µg/L in early pregnancy on use of supplements, and to explore which factors were associated with changes in iron status by different iron indicators to 14 weeks postpartum.MethodsA multi-ethnic population-based cohort study of 573 pregnant women examined at mean gestational week (GW) 15 (enrolment), at mean GW 28 and at the postpartum visit (mean 14 weeks after delivery). Women with SF < 20 µg/L at enrolment were recommended 30-50 mg iron supplementation and supplement use was assessed at all visits. Change of SF, soluble transferrin receptor and total body iron from enrolment to postpartum were calculated by subtracting the concentrations at the postpartum visit from that at enrolment. Linear and logistic regression analyses were performed to assess associations between use of supplements in GW 28 and changes in iron status and postpartum iron deficiency/anaemia. Change of iron status was categorized into ‘steady low’, ‘improvement’, ‘deterioration’, and ‘steady high’ based on SF status at enrolment and postpartum. Multinomial logistic regression analyses were performed to identify factors associated with change of iron status.ResultsAt enrolment, 44% had SF < 20 µg/L. Among these women (78% non-Western European origin), use of supplements increased from 25% (enrolment) to 65% (GW 28). Use of supplements in GW 28 was associated with improved iron levels by all three indicators (p < 0.05) and with haemoglobin concentration (p < 0.001) from enrolment to postpartum, and with lower odds of postpartum iron deficiency by SF and TBI (p < 0.05). Factors positively associated with ‘steady low’ were: use of supplements, postpartum haemorrhage, an unhealthy dietary pattern and South Asian ethnicity (p ≤ 0.01 for all); with ‘deterioration’: postpartum haemorrhage, an unhealthy dietary pattern, primiparity and no use of supplements (p < 0.01 for all), and with ‘improvement’: use of supplements, multiparity and South Asian ethnicity (p < 0.03 for all).ConclusionsBoth supplement use and iron status improved from enrolment to the postpartum visit among women recommended supplementation. Dietary pattern, use of supplements, ethnicity, parity and postpartum haemorrhage were identified as factors associated with change in iron status.

Association of Number of Live Births With Electrocardiographic and Cardiac Structural Changes.

Background Pregnancy is a major life event unique to women and leads to significant hemodynamic, hormonal, and metabolic changes. The purpose of this study was to use the DHS (Dallas Heart Study), a multiethnic population-based cohort study of Dallas county adults, to evaluate the association between number of live births and cardiac magnetic resonance imaging and ECG parameters later in life. Methods and Results Women were included if they had data on self-reported live births and ECG or cardiac magnetic resonance imaging measurements. The 3014 women were stratified by number of live births: 0, 1, 2, 3, 4, and ≥5. Higher number of live births was associated with larger left ventricular (LV) end-diastolic volume (β, 1.31±0.41; P<0.01), LV end-systolic volume (β, 0.83±0.24; P<0.01), and LV mass (β, 1.13±0.49; P=0.02) and lower LV ejection fraction (β, -0.004±0.0014; P<0.01). Increasing parity was associated with longer PR intervals (β, 1.07±0.38; P<0.01). Subgroup analysis by race demonstrated that the association between number of live births and magnetic resonance imaging parameters (LV end-diastolic volume, LV end-systolic volume, and LV ejection fraction) only remained significant in Black women (P value for interaction <0.05). Conclusions Increasing number of live births was associated with electrocardiographic and cardiac structural changes in a multiethnic population. When stratified by race and ethnicity, magnetic resonance imaging structural changes only remained significant in Black participants. Whether these changes are pathologic and increase the risk of heart failure or arrhythmias in multiparous women warrants further investigation.

ASSOCIATION BETWEEN THE REFLECTION MAGNITUDE AND BLOOD-PRESSURE IN A MULTI-ETHNIC COHORT: THE HELIUS STUDY

Objective: The reflection magnitude (RM), the ratio of the amplitudes of the backward and forward central arterial pressure waves, has been shown to be predictive for future cardiovascular events, but the association between blood pressure (BP) and RM remains unknown. We aimed to assess the association between RM, BP and hypertension in a large multi-ethnic population-based cohort study. Design and method: We assessed RM in 10 195 individuals of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan origin aged between 18–70 years (54.2% female) participating in the HEalthy Life in an Urban Setting (HELIUS) study. To determine RM, central arterial pressure and flow were reconstructed from non-invasive finger BP measurements using a generalized transfer function and Windkessel model, whereafter wave separation was performed (Fig 1, panel A &amp; B). Hypertension was defined based on office-BP and use of BP lowering medication. Associations between RM and systolic- and diastolic BP, hypertension, and hypertension mediated end-organ damage were assessed using regression models with correction for age, height, ethnicity and an interaction term for sex. Results: Mean RM was 62.5% (SD 8.0) in men and 63.8% (SD 8.1) in women. For every 10 mmHg increase in systolic BP, RM increased linearly by 1.35 (95% CI 1.23–1.46) from 120 mmHg onwards, while for every 10 mmHg increase in diastolic BP above 80 mmHg RM increased by 1.99 (95% CI 1.61 – 2.38) (Fig 1, panel C &amp; D). RM was 2.40 (95% CI 2.04–2.76) higher in hypertensive men and 3.82 (95% CI 3.46–4.19) higher in hypertensive women compared to normotensive men and women. RM was 1.64 (95% CI 1.09–2.20) and 0.94 (95% CI 0.37–1.52) higher in hypertensive men and women with ECG-based left ventricular hypertrophy or increased albuminuria compared to hypertensive men and women without hypertensive organ damage. Following correction for height ethnic and sex differences in RM were attenuated, however the relation with BP did not change. Conclusions: Hypertension is associated with a higher RM in men and women of different ethnic origins, and may, in part, explain disparities in hypertension associated cardiovascular risk.

Incidence and progression of diabetic retinopathy in a multi-ethnic US cohort: the Multi-Ethnic Study of Atherosclerosis

AimTo provide contemporary longitudinal data on the incidence and progression of diabetic retinopathy (DR) in a multi-ethnic population of whites, African Americans, Chinese and Hispanics in the United States.MethodsA prospective,...

Associations Between Child Maltreatment, Autonomic Regulation, and Adverse Cardiovascular Outcome in an Urban Population: The HELIUS Study.

IntroductionA mounting body of literature emphasizes the potential negative effects of adverse childhood experiences (ACEs) on both mental and physical health throughout life, including an increased risk for developing cardiovascular disease (CVD). Since CVD is one of the leading causes of mortality and morbidity worldwide, it is of great importance to advance our understanding of the effects of on CVD. This holds both for the actual incidence and for intermediate biological pathways that may convey CVD risk, such as imbalance in autonomic nervous system regulation, resulting in a chronically heightened sympathetic activity and lowered reactivity. In a large urban, multi-ethnic population-based cohort study we investigated whether there is an association between child maltreatment, CVD incidence and autonomic regulation.MethodsWithin the Health in an Urban Setting (HELIUS) study, a large, multi-ethnic population cohort study including n = 22,165 Amsterdam residents, we used logistic regression analyses to investigate the association between the number of self-reported types of child maltreatment (range 0–4), and self-reported adverse cardiovascular outcome (aCVO). Self-reported child maltreatment included emotional neglect, emotional abuse, physical abuse, and sexual abuse. Furthermore, in a subsample (n = 10,260), mean age 44.3, we investigated associations between child maltreatment, autonomic regulation, and aCVO using linear regression analyses. Both baroreflex sensitivity (BRS) and heart rate variability (HRV) were assessed as non-invasive indices of autonomic regulation.ResultsThe number of endorsed child maltreatment types was significantly associated with a higher aCVO risk. The association remained significant after adjustment for demographic, socioeconomic, health-behavioral, and psychological covariates (p = 0.011, odds ratio: 1.078, confidence interval: 1.018–1.142). The cumulative exposure to child maltreatment was negatively associated with BRS and HRV, but the association was no longer significant after correction for socioeconomic and demographic covariates.ConclusionIn a large, multi-ethnic urban-population cohort study we observed a positive association between number of endorsed child maltreatment types and self-reported aCVO but not autonomic regulation, over and above the effect of relevant demographic, health, and psychological factors. Future studies should examine the potential role of the dynamics of autonomic dysregulation as potential underlying biological pathways in the association between ACEs and CVD, as this could eventually facilitate the development of preventive and therapeutic strategies for CVD.

Differences in Chlamydia trachomatis seroprevalence between ethnic groups cannot be fully explained by socioeconomic status, sexual healthcare seeking behavior or sexual risk behavior: a cross-sectional analysis in the HEalthy LIfe in an Urban Setting (HELIUS) study

BackgroundIn the Netherlands, there are strong disparities in Chlamydia trachomatis (CT) prevalence between ethnic groups. The current study aims to identify whether socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior may explain differences in CT seroprevalence between ethnic groups.MethodsWe used 2011–2014 baseline data of the HELIUS (HEalthy LIfe in an Urban Setting) study, a multi-ethnic population-based cohort study in Amsterdam, the Netherlands, including participants from Dutch, African Surinamese, South-Asian Surinamese, Ghanaian, Moroccan and Turkish origin. For this analysis, we selected sexually active, heterosexual participants aged 18–34 years old. CT seroprevalence was determined using a multiplex serology assay. The CT seroprevalence ratios between different ethnicities are calculated and adjusted for potential indicators of socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior.ResultsThe study population consisted of 2001 individuals (52.8% female) with a median age of 28 years (IQR 24–31). CT seropositivity differed by ethnicities and ranged from 71.6% (African Surinamese), and 67.9% (Ghanaian) to 31.1% (Turkish). The CT seroprevalence ratio of African Surinamese was 1.72 (95% CI 1.43–2.06) and 1.52 (95% CI 1.16–1.99) of Ghanaian as compared to the Dutch reference group, after adjustment for socioeconomic status, sexual risk behavior and sexual healthcare seeking behavior.ConclusionsIndicators of socioeconomic status, sexual risk behavior, and sexual health seeking behavior could not explain the higher CT seroprevalence among African Surinamese and Ghanaian residents of Amsterdam.

25-hydroxyvitamin D concentrations during fetal life and bone health in children aged 6 years: a population-based prospective cohort study

25-hydroxyvitamin D (25[OH]D) concentrations during fetal life might have long-lasting effects on skeletal development, but results from previous studies are inconsistent. We investigated the associations of maternal and fetal 25(OH)D concentrations with childhood bone health. In a prospective multiethnic population-based cohort study, embedded within the Generation R Study (Rotterdam, Netherlands), pregnant women living in the study area with an expected delivery date between April 1, 2002, and Jan 1, 2006, were eligible for participation in the study at our research centre in the Erasmus MC-Sophia Children's Hospital. We measured maternal 25(OH)D concentrations during mid-pregnancy (at a median of 20·4 weeks gestation [IQR 19·9-21·1]) and fetal 25(OH)D concentrations at birth (at a median of 40·1 weeks gestation [39·3-41·0]). We measured total-body bone mineral density, bone mineral content (BMC), area-adjusted BMC, and bone area using dual-energy X-ray absorptiometry (DXA) in offspring at 6 years of age. We examined associations using multivariable linear regression models, adjusted for several sociodemographic and lifestyle variables, and for child's height. We enrolled 9901 mother-and-child pairs and obtained both mid-pregnancy maternal 25(OH)D concentrations and offspring DXA scans at age 6 years in 4815 pairs. Severe maternal 25(OH)D deficiency (<25 nmol/L) during mid-pregnancy was associated with higher offspring BMC (4·71 g, 95% CI 1·09 to 8·33; p=0·011) and larger bone area (7·54 cm2, 2·99 to 12·11; p=0·001) at age 6 years, compared with maternal 25(OH)D sufficiency (≥50 nmol/L) during mid-pregnancy. However, in a subgroup of children with available data on 25(OH)D concentrations at 6 years (n=3034), such associations for BMC (4·67 g, -0·05 to 9·39; p=0·052) and bone area (5·25 cm2, -0·41 to 10·91; p=0·069) were no longer significant after adjustment for the child's own 25(OH)D concentrations. No associations were seen between maternal 25(OH)D concentrations in mid-pregnancy and offspring bone mineral density (1·07 mg/cm2, -1·84 to 3·99; p=0·47) or area-adjusted BMC (-1·58 g, -4·72 to 1·61; p=0·32), and the association with skeletal parameters at 6 years did not differ by maternal BMI, maternal calcium intake, child sex, or weight status. Similar associations were seen with fetal 25(OH)D concentrations at birth. We found inverse associations between 25(OH)D concentrations during fetal life with BMC and bone area in childhood, but these associations were no longer significant after adjustment for childhood 25(OH)D status. Our data suggest that 25(OH)D concentrations during childhood might be more relevant for bone outcomes than than 25(OH)D concentrations during fetal life. Erasmus University Medical Center, Organization for Health Research and Development (ZonMw), Organization for Scientific Research (NWO), the Ministry of Health, Welfare and Sport.

Cardiovascular Disease Burden: Evolving Knowledge of Risk Factors in Myocardial Infarction and Stroke through Population-Based Research and Perspectives in Global Prevention.

Current knowledge and research perspectives on the top ranking causes of mortality worldwide, i.e., ischemic heart disease and cerebrovascular diseases have developed rapidly. In fact, until recently, the evidence describing the incidence of acute myocardial infarction, the underlying risk factors, and the clinical outcomes of those who have this acute ischemic coronary event has largely been based on studies conducted in developed countries, with limited data for women and usually of low-ethnic diversity. Recent reports by the WHO have provided striking public health information, i.e., the global burden of cardiovascular mortality for the next decades is expected to predominantly occur among developing countries. Therefore, multiethnic population-based research including prospective cohorts and, when appropriate, case–control studies, is warranted. These studies should be specifically designed to ascertain key public health measures, such as geographic variations in non-communicable diseases, diagnosis of traditional and potential newly discovered risk factors, causes of death and disability, and gaps for improvement in healthcare prevention (both primary and secondary) and specific treatments. As an example, a multinational, multiethnic population-based cohort study is the Prospective Urban and Rural Epidemiology study, which is the largest global initiative of nearly 200,000 adults aged 35–70 years, looking at environmental, societal, and biological influences on obesity and chronic health conditions, such as ischemic heart disease, stroke, and cancer among urban and rural communities in low-, middle-, and high-income countries, with national, community, household, and individual-level data. Implementation of population-based strategies is crucial to optimizing limited health system resources while improving care and cardiovascular morbidity and mortality.

Ethnic Disparities in General and Abdominal Adiposity at School Age: A Multiethnic Population-Based Cohort Study in The Netherlands

Background/Aims: Ethnic differences in obesity prevalence have been reported. We examined ethnic differences in general and abdominal fat distribution in school-age children and the influence of parental prepregnancy, pregnancy, and childhood factors on these differences. Methods: We performed a multiethnic population-based prospective cohort study among 5,244 children with information about prepregnancy factors, pregnancy, and childhood factors. At the age of 6 years, the BMI, total fat mass, android/gynoid fat mass ratio, and preperitoneal fat mass were assessed via dual-energy X-ray absorptiometry and abdominal ultrasound. Results: The overweight and obesity prevalences among Dutch children were 10.0 and 2.1%, respectively. Higher prevalences were observed among Cape Verdean (21.0 and 10.3%), Dutch Antillean (18.4 and 13.8%), Moroccan (20.6 and 7.7%), Surinamese-Creole (13.4 and 7.7%), Surinamese-Hindustani (12.3 and 6.2%), and Turkish (23.8 and 12.0%) children. In the models adjusted for age and sex only, Moroccan, Surinamese-Hindustani, and Turkish children had a higher total fat mass than Dutch children, whereas Surinamese-Creole children had a lower total fat mass. Compared to Dutch children, the android/gynoid fat mass ratio was higher in Moroccan, Surinamese-Hindustani, and Turkish children, whereas the preperitoneal fat mass was higher among Dutch Antillean, Moroccan, Surinamese-Hindustani, and Turkish children (all p < 0.05). Prepregnancy factors explained up to 73% of these differences. In addition to prepregnancy factors, pregnancy factors explained up to 34% of the differences. Childhood factors did not significantly explain these associations. Conclusions: All ethnic minority groups had higher risks of overweight and obesity than Dutch children. Moroccan, Surinamese-Hindustani, and Turkish children also had an adverse body fat profile. Prepregnancy and pregnancy might be critical periods for preventive strategies focused on the reduction of ethnic disparities in childhood adiposity.

Plasma adiponectin to predict incident cancer in a large multiethnic population-based cohort study.

1560 Background: Previous retrospective studies have suggested an inverse relationship between cancer and markers of insulin resistance, including adiponectin. Whether circulating levels of adiponectin are associated with future cancer incidence has not been well demonstrated. As such, we examined the association of adiponectin on the risk of future cancer development in a large population based cohort study. Methods: The Dallas Heart Study (DHS) is a multiethnic population based study of 3,531 Dallas County residents with an intentional oversampling of minorities which are underrepresented in other population studies. Incident and prevalent cancer cases were identified in the DHS by the Texas Cancer Registry. Cases were defined as ‘incident’ if they were diagnosed 24 months after enrollment into DHS. Fasting blood samples were obtained from DHS participants between 2000 and 2002, and used for biomarker analysis. Univariate and multivariate analysis was performed to test the association of incident cancer and adiponectin after adjusting for age, diabetes status, gender, ethnicity and body mass index (BMI). Results: Of 3,531 individuals, 150 incident cancer cases were diagnosed. The study population comprised 55.8% females, 51.5% were black and 39.6% had a BMI above 30 kg/m2. Mean adiponectin was 8.12 μg/ml in incident cancer group and 7.46 μg/ml in non-cancer group (p=0.129). In multivariable analysis, adiponectin was not an independent predictor of cancer incidence after adjusting for age, diabetes status, gender, ethnicity and BMI (p=0.167) Conclusions: Previous population based studies have demonstrated conflicting results on the association of markers insulin resistance, including adiponectin, and cancer incidence. In this study of a predominant ethnic minority population, an association between adiponectin and cancer incidence was not seen. Further prospective studies are needed to understand the association between markers of insulin resistance and risk of future cancer risk.

Fetal head circumference, operative delivery, and fetal outcomes: a multi-ethnic population-based cohort study.

BackgroundOperative delivery procedures, such as primary cesarean section, vacuum-assisted, and forceps-assisted vaginal delivery increase maternal and fetal morbidity, and the cost of care. We evaluated whether large fetal head circumference (FHC) independently increases risk of such interventions, as well as fetal distress or low Apgar score, in anatomically normal infants.MethodsWe conducted a population-based retrospective cohort study using Washington State birth certificate data. We included singleton, term infants born to nulliparous mothers from 2003–2009. We compared mode of delivery and fetal outcomes in 10,750 large-FHC (37-41 cm) infants relative to 10,750 average-FHC (34 cm) infants, frequency matched by birth-year.ResultsLarge-FHC infants were nearly twice as likely to be delivered by primary cesarean section as average-FHC infants (unadjusted relative risk [RR] 1.84, 95% confidence interval [CI]: 1.77, 1.92). The RR for primary cesarean section associated with large-FHC was largest for mothers aged 19 years or less (RR 2.28; 95% CI: 1.99, 2.61), and smallest for mothers aged 35 years or greater (RR 1.51; 95% CI: 1.37, 1.66) [test of homogeneity, p < 0.001]. Large-FHC infants were at increased risk of vacuum-assisted vaginal delivery (RR 1.55; 95% CI: 1.43, 1.69), and forceps-assisted vaginal delivery (RR 1.61; 95% CI: 1.32, 1.97). There was no difference in risk of fetal distress (RR 0.97; 95% CI: 0.89, 1.07) for large-FHC versus average-FHC infants. Risk estimates were unaffected by adjustment for potential confounders.ConclusionsNulliparous mothers of large-FHC infants are at increased risk of primary cesarean section, vacuum-assisted and forceps-assisted vaginal delivery relative to mothers of average-FHC infants. Maternal age modifies the association between FHC and primary cesarean section.

Metabolic changes in urine during and after pregnancy in a large, multiethnic population-based cohort study of gestational diabetes.

This study aims to identify novel markers for gestational diabetes (GDM) in the biochemical profile of maternal urine using NMR metabolomics. It also catalogs the general effects of pregnancy and delivery on the urine profile. Urine samples were collected at three time points (visit V1: gestational week 8–20; V2: week 28±2; V3∶10–16 weeks post partum) from participants in the STORK Groruddalen program, a prospective, multiethnic cohort study of 823 healthy, pregnant women in Oslo, Norway, and analyzed using 1H-NMR spectroscopy. Metabolites were identified and quantified where possible. PCA, PLS-DA and univariate statistics were applied and found substantial differences between the time points, dominated by a steady increase of urinary lactose concentrations, and an increase during pregnancy and subsequent dramatic reduction of several unidentified NMR signals between 0.5 and 1.1 ppm. Multivariate methods could not reliably identify GDM cases based on the WHO or graded criteria based on IADPSG definitions, indicating that the pattern of urinary metabolites above micromolar concentrations is not influenced strongly and consistently enough by the disease. However, univariate analysis suggests elevated mean citrate concentrations with increasing hyperglycemia. Multivariate classification with respect to ethnic background produced weak but statistically significant models. These results suggest that although NMR-based metabolomics can monitor changes in the urinary excretion profile of pregnant women, it may not be a prudent choice for the study of GDM.

P2-293 HELIUS: the design of a large multi-ethnic population-based cohort study

IntroductionAs a result of immigration, European societies are becoming increasingly ethnically diverse. In health (care) studies, however, ethnic minorities are usually excluded. There is now a growing awareness that it...