DNA methylation risk score for type 2 diabetes is associated with gestational diabetes.

BACKGROUND: Gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM) share many pathophysiological factors including genetics, but whether epigenetic marks are shared is unknown. We aimed to test whether a DNA methylation risk score (MRS) for T2DM was associated with GDM across ancestry and GDM criteria. METHODS: In two independent pregnancy cohorts, EPIPREG (n = 480) and EPIDG (n = 32), DNA methylation in peripheral blood leukocytes was measured at a gestational age of 28 ± 2. We constructed an MRS in EPIPREG and EPIDG based on CpG hits from a published epigenome-wide association study (EWAS) of T2DM. RESULTS: With mixed models logistic regression of EPIPREG and EPIDG, MRS for T2DM was associated with GDM: odd ratio (OR)[95% CI]: 1.3 [1.1-1.8], P = 0.002 for the unadjusted model, and 1.4 [1.1-1.7], P = 0.00014 for a model adjusted by age, pre-pregnant BMI, family history of diabetes and smoking status. Also, we found 6 CpGs through a meta-analysis (cg14020176, cg22650271, cg14870271, cg27243685, cg06378491, cg25130381) associated with GDM, and some of their methylation quantitative loci (mQTLs) were related to T2DM and GDM. CONCLUSION: For the first time, we show that DNA methylation marks for T2DM are also associated with GDM, suggesting shared epigenetic mechanisms between GDM and T2DM.

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.

BACKGROUND: We 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. METHODS: A 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. RESULTS: At 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). CONCLUSIONS: Both 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.

Lipid and lipoprotein concentrations during pregnancy and associations with ethnicity.

BACKGROUND: To describe ethnic differences in concentrations of lipids and lipoproteins, and their changes, during pregnancy to postpartum. METHODS: This was a population-based cohort study conducted in primary antenatal care in Norway. The participants (n = 806) were healthy, pregnant women, 59% were ethnic minorities. Outcomes were triglycerides, total cholesterol, HDL- and LDL-cholesterol, analysed from fasting blood samples drawn at gestational age (weeks) 15, 28 and 14 weeks postpartum. We performed linear regression models and linear mixed models to explore the total effect of ethnicity on the outcomes, adjusting for gestational age /week postpartum, maternal age and education. The analyses are corrected for multiple testing using the Bonferroni correction. RESULTS: At gestational age 15, triglyceride concentrations were lower in women of African origin (1.03 mmol/mol (95% CI: 0.90, 1.16)) and higher in women of South Asian (primarily Pakistan and Sri Lanka) origin (1.42 mmol/mol (1.35, 1.49)) and East Asian (primarily Vietnam, Philippines and Thailand) origin (1.58 mmol/mol (1.43, 1.73)) compared with Western Europeans (1.26 mmol/mol (1.20, 1.32)). Women of Asian and African origin had a smaller increase in triglycerides, LDL- and total cholesterol from gestational age 15 to 28. At gestational age 28, LDL-cholesterol levels were lowest among East Asians (3.03 mmol/mol (2.72, 3.34)) compared with Western Europeans (3.62 mmol/mol (3.50, 3.74)). Triglycerides and HDL-cholesterol were lower postpartum than at gestational age 15 in all groups, but the concentration of LDL-cholesterol was higher, except in Africans. South and East Asian women had lower HDL-cholesterol and higher triglycerides postpartum, while African women had lower triglycerides than Western Europeans. CONCLUSION: We found significant differences in the concentrations of lipids and lipoproteins and their changes during pregnancy and the early postpartum period related to ethnic origin.

Are there subgroups of chronic fatigue syndrome? An exploratory cluster analysis of biological markers.

BACKGROUND: Chronic fatigue syndrome (CFS) is defined according to subjective symptoms only, and several conflicting case definition exist. Previous research has discovered certain biological alterations. The aim of the present study was to explore possible subgroups based on biological markers within a widely defined cohort of adolescent CFS patients and investigate to what extent eventual subgroups are associated with other variables. METHODS: The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL) has previously performed detailed investigation of immunological, autonomic, neuroendocrine, cognitive and sensory processing functions in an adolescent group of CFS patients recruited according to wide diagnostic criteria. In the present study, hierarchical cluster analyses (Ward's method) were performed using representative variables from all these domains. Associations between clusters and constitutional factors (including candidate genetic markers), diagnostic criteria, subjective symptoms and prognosis were explored by standard statistical methods. RESULTS: A total of 116 patients (26.7% males, mean age 15.4 years) were included. The final cluster analyses revealed six clusters labelled pain tolerant & good cognitions, restored HPA dynamics, orthostatic intolerance, low-grade inflammation, pain intolerant & poor cognitions, and high vagal (parasympathetic) activity, respectively. There was substantial overlap between clusters. The pain intolerant & poor cognitions-cluster was associated with low functional abilities and quality of life, and adherence to the Canada 2003 diagnostic criteria for CFS. No other statistically significant cluster associations were discovered. CONCLUSION: Within a widely defined cohort of adolescent CFS patients, clusters could be delineated, but no distinct subgroups could be identified. Associations between clusters and constitutional factors, subjective symptoms and prognosis were scarce. These results question the clinical usefulness of searching for CFS subgroups, as well as the validity of the most "narrow" CFS diagnostic criteria. TRIAL REGISTRATION: Clinical Trials NCT01040429.

Identifying women with gestational diabetes based on maternal characteristics: an analysis of four Norwegian prospective studies.

BACKGROUND: There is still no worldwide agreement on the best diagnostic thresholds to define gestational diabetes (GDM) or the optimal approach for identifying women with GDM. Should all pregnant women perform an oral glucose tolerance test (OGTT) or can easily available maternal characteristics, such as age, BMI and ethnicity, indicate which women to test? The aim of this study was to assess the prevalence of GDM by three diagnostic criteria and the predictive accuracy of commonly used risk factors. METHODS: We merged data from four Norwegian cohorts (2002-2013), encompassing 2981 women with complete results from a universally offered OGTT. Prevalences were estimated based on the following diagnostic criteria: 1999WHO (fasting plasma glucose (FPG) ≥7.0 or 2-h glucose ≥7.8 mmol/L), 2013WHO (FPG ≥5.1 or 2-h glucose ≥8.5 mmol/L), and 2017Norwegian (FPG ≥5.3 or 2-h glucose ≥9 mmol/L). Multiple logistic regression models examined associations between GDM and maternal factors. We applied the 2013WHO and 2017Norwegian criteria to evaluate the performance of different thresholds of age and BMI. RESULTS: The prevalence of GDM was 10.7, 16.9 and 10.3%, applying the 1999WHO, 2013WHO, and the 2017Norwegian criteria, respectively, but was higher for women with non-European background when compared to European women (14.5 vs 10.2%, 37.7 vs 13.8% and 27.0 vs 7.8%). While advancing age and elevated BMI increased the risk of GDM, no risk factors, isolated or in combination, could identify more than 80% of women with GDM by the latter two diagnostic criteria, unless at least 70-80% of women were offered an OGTT. Using the 2017Norwegian criteria, the combination "age≥25 years or BMI≥25 kg/m2" achieved the highest sensitivity (96.5%) with an OGTT required for 93% of European women. The predictive accuracy of risk factors for identifying GDM was even lower for non-European women. CONCLUSIONS: The prevalence of GDM was similar using the 1999WHO and 2017Norwegian criteria, but substantially higher with the 2013WHO criteria, in particular for ethnic non-European women. Using clinical risk factors such as age and BMI is a poor pre-diagnostic screening method, as this approach failed to identify a substantial proportion of women with GDM unless at least 70-80% were tested.

Body mass index trajectories up to preschool age in a multi-ethnic population; relations with maternal gestational diabetes, BMI and gestational weight gain.

AIM: Independent effects of gestational diabetes (GDM), maternal prepregnant obesity and gestational weight gain on offspring BMI and obesity are scarcely documented. We examined associations between GDM and children's BMI trajectories from birth to 4-5 years age, and effects of prepregnant obesity and gestational weight gain not mediated through GDM. METHODS: We included 734 children from a population-based, multi-ethnic cohort of women and their offspring followed from early pregnancy. All women were screened for GDM. Using linear mixed models, we explored associations between maternal factors and children's BMI development through seven serial measurements. RESULTS: At birth and age 4-5 years, BMI of children exposed to GDM was similar to those not exposed. However, they had slower BMI growth (B = -0.1 BMI units/month (95% CI: -0.17, -0.04)) during first 6 months, and faster BMI growth from 6 months to 4-5 years. Maternal prepregnant obesity was associated with higher child BMI at birth, and thereafter persistently higher BMI. High gestational weight gain was associated with faster BMI growth from 6 months to 4-5 years. CONCLUSION: Effects of maternal GDM, prepregnant obesity, and gestational weight gain on children's BMI and BMI trajectories from birth to preschool age differed in relation to effect size, timing and direction.

Blood-based epigenetic estimators of chronological age in human adults using DNA methylation data from the Illumina MethylationEPIC array.

BACKGROUND: Epigenetic clocks have been recognized for their precise prediction of chronological age, age-related diseases, and all-cause mortality. Existing epigenetic clocks are based on CpGs from the Illumina HumanMethylation450 BeadChip (450 K) which has now been replaced by the latest platform, Illumina MethylationEPIC BeadChip (EPIC). Thus, it remains unclear to what extent EPIC contributes to increased precision and accuracy in the prediction of chronological age. RESULTS: We developed three blood-based epigenetic clocks for human adults using EPIC-based DNA methylation (DNAm) data from the Norwegian Mother, Father and Child Cohort Study (MoBa) and the Gene Expression Omnibus (GEO) public repository: 1) an Adult Blood-based EPIC Clock (ABEC) trained on DNAm data from MoBa (n = 1592, age-span: 19 to 59 years), 2) an extended ABEC (eABEC) trained on DNAm data from MoBa and GEO (n = 2227, age-span: 18 to 88 years), and 3) a common ABEC (cABEC) trained on the same training set as eABEC but restricted to CpGs common to 450 K and EPIC. Our clocks showed high precision (Pearson correlation between chronological and epigenetic age (r) > 0.94) in independent cohorts, including GSE111165 (n = 15), GSE115278 (n = 108), GSE132203 (n = 795), and the Epigenetics in Pregnancy (EPIPREG) study of the STORK Groruddalen Cohort (n = 470). This high precision is unlikely due to the use of EPIC, but rather due to the large sample size of the training set. CONCLUSIONS: Our ABECs predicted adults' chronological age precisely in independent cohorts. As EPIC is now the dominant platform for measuring DNAm, these clocks will be useful in further predictions of chronological age, age-related diseases, and mortality.

Childhood Fat and Lean Mass: Differing Relations to Vascular Structure and Function at Age 8 to 9 Years

Objective- Childhood body mass index (BMI) has been related to vascular structure and function. However, little is known about the differing contributions of fat and lean mass to this relationship. Our objectives were to relate the fat and lean mass (bone excluded) components of BMI (fat mass index and lean mass index; mass [kg]/height [m]2) to vascular measures in prepubertal children. Approach and Results- In the UK Southampton Women's Survey mother-offspring cohort, 983 children had dual x-ray absorptiometry and vascular measurements at 8 to 9 years. Using linear regression analyses, we found that most vascular measures were related to BMI, but fat and lean mass contributed differently. Systolic blood pressure was positively associated with both fat mass index (ß=0.91 [95% CI, 0.52-1.30] mm Hg) and lean mass index (ß=2.16 [95% CI, 1.47-2.85] mm Hg), whereas pulse rate was positively associated with fat mass index (ß=0.93 [95% CI, 0.48-1.38] b/min) but negatively associated with lean mass index (ß=-1.79 [95% CI, -2.59 to -0.99] b/min). The positive relation between BMI and carotid intima-media thickness was mainly due to a positive association with lean mass index (ß=0.013 [95% CI, 0.008-0.019] mm). Carotid-femoral pulse wave velocity, but not carotid-radial pulse wave velocity, was positively associated with fat mass index (ß=0.06 [95% CI, 0.03-0.09] m/s). For systolic blood pressure, carotid-femoral pulse wave velocity and reactive hyperemia significant interactions indicated that the association with fat mass depended on the amount of lean mass. Conclusions- In prepubertal children, differences in vascular structure and function in relation to BMI probably represent combinations of adverse effects of fat mass, adaptive effects of body size, and relatively protective effects of lean mass.

Effects of applying universal fetal growth standards in a Scandinavian multi-ethnic population.

INTRODUCTION: The question of whether universal growth charts can be used in multi-ethnic settings is of general interest. The Intergrowth-21st fetal growth and newborn size standards are suggested to represent optimal fetal growth regardless of country origin. Our aim was to examine whether women fulfilling the strict Intergrowth-21st inclusion criteria were healthier, showed less ethnic differences in fetal growth and newborn size, and less adverse perinatal outcomes. MATERIAL AND METHODS: Data were drawn from a population-based multi-ethnic cohort of 823 presumably healthy pregnant women in Oslo, Norway. We assessed differences in fetal and neonatal gestational age specific z-scores and compared maternal health parameters, pregnancy and birth complications between pregnancies fulfilling and not fulfilling the Intergrowth-21st criteria. RESULTS: Only 21% of pregnancies enrolled in our cohort fulfilled the Intergrowth-21st criteria. Fetal growth deviated substantially from the new standards, in particular for ethnic Europeans. Ethnic differences persisted in pregnancies fulfilling the criteria. In South Asian fetuses, estimated fetal weight was -0.60 SD (95% confidence interval -1.00, -0.20) lower at 24 gestational weeks, and birthweight was -0.62 SD (-0.95, -0.29) lower, compared with ethnic Europeans. Corresponding numbers for Middle-East/North Africans were -0.13 (-0.62, 0.36) and -0.60 (-1.00, -0.20). Maternal health indicators and birth complications were similar in women fulfilling and not fulfilling the criteria, but the relation depended on ethnic origin. CONCLUSIONS: In an urban multi-ethnic Norwegian population, applying an extensive list of criteria to define "healthy" pregnancies excludes the majority of women but does not cancel ethnic differences in fetal growth.

Contrasting patterns of overweight and thinness among preschool children of different ethnic groups in Norway, and relations with maternal and early life factors.

BACKGROUND: Childhood obesity is a worldwide health challenge and risk factor for adult life obesity, which predisposes to development of type 2 diabetes and cardiovascular diseases. However, also thinness in early life has been related to these diseases, especially if followed by fat gain. In European countries, susceptibility to cardio-metabolic diseases varies considerably between ethnic groups. We investigated ethnic differences in overweight and thinness in a multi-ethnic, population-based cohort of preschool children in Norway, and associations with maternal and early postnatal factors. METHODS: Participants were children aged 4-5 years (n = 570) drawn from the population-based STORK Groruddalen cohort of healthy women and offspring followed from early pregnancy. Ethnic groups were: European (n = 298), South Asian (n = 154), and Middle East/North African (n = 118). Children's growth data were provided from routine visits at local Child Health Clinics. Weight status was defined by the International Obesity Task Force. Using multinomial logistic regression analysis, we explored ethnic differences in overweight and thinness, and associations with maternal-, pre, - and postnatal factors. RESULTS: Children of Middle East/North African origin had higher prevalence of overweight (22.0%) compared to European (12.8%) children, and in adjusted logistic regression analysis almost the double risk (OR 1.98; 95%CI: 1.08-3.63). Prevalence was lower in children of South Asian origin (5.2%). Children with South Asian background had higher prevalence of thinness (26.0%) compared to ethnic Europeans (10.4%), and the double risk (OR 2.20; 95%CI: 1.25-3.87) in adjusted models. Applying newly suggested BMI adjustments in South Asian children, taking into account their relatively increased adiposity, markedly increased the prevalence of overweight, and decreased the prevalence of thinness in this subgroup. Birthweight and maternal prepregnant overweight were strongly, positively associated with overweight, and inversely associated with thinness. Lower maternal age was associated with overweight only. CONCLUSIONS: In a multi-ethnic cohort we found strikingly different patterns of overweight and thinness among children of different ethnic groups at age 4-5 years, and a strong association between maternal BMI and their children's weight status. More knowledge is needed on what characterizes and what promotes healthy growth patterns in multi-ethnic populations.

Recent gestational diabetes was associated with mothers stopping predominant breastfeeding earlier in a multi-ethnic population.

AIM: It has previously been shown that breastfeeding may reduce the risk of type 2 diabetes in mothers with recent gestational diabetes mellitus (GDM). This study compared the cessation of predominant breastfeeding in mothers with and without recent GDM in a multi-ethnic population. METHODS: From May 2008 to May 2010, healthy pregnant women attending antenatal care provided by community health services in Eastern Oslo, Norway were recruited. We included 616 women-58% non-Western-and interviewed and examined them at a mean of 15 and 28 weeks of gestation and 14 weeks' postpartum. Cox regression models examined the association between GDM, as assessed by the 2013 World Health Organization criteria, and breastfeeding cessation. RESULTS: Overall, 190 of the 616 (31%) mothers had GDM and they ended predominant breastfeeding earlier than mothers without GDM, with an adjusted hazard ratio (aHR) of 1.33 and 95% confidence interval (95% CI) of 1.01-1.77. Mothers of South Asian origin ended predominant breastfeeding earlier than Western European mothers in the adjusted analysis (aHR 1.53, 95% CI: 1.04-2.25), but Middle Eastern mothers did not. CONCLUSION: Recent gestational diabetes was associated with earlier cessation of predominant breastfeeding in Western European and non-Western women.

Vitamin D levels during pregnancy and associations with birth weight and body composition of the newborn: a longitudinal multiethnic population-based study.

We investigated associations between serum 25-hydroxyvitamin D (25(OH)D) in pregnancy and birth weight and other neonatal anthropometric measures. The present study was a population-based, multiethnic cohort study of 719 pregnant women (59 % ethnic minorities) in Oslo, Norway, delivering a singleton neonate at term and with birth weight measurements. In a representative sample, anthropometric measurements were taken. Maternal 25(OH)D was measured at gestational weeks 15 and 28. Women with 25(OH)D <37 nmol/l were recommended vitamin D3 supplementation. Separate linear regression analyses were performed to model the associations between 25(OH)D and each of the outcomes: birth weight, crown-heel length, head circumference, abdominal circumference, sum of skinfolds, mid-upper arm circumference and ponderal index. In early pregnancy, 51 % of the women were vitamin D deficient (25(OH)D<50 nmol/l). In univariate analyses and in models adjusting for maternal age, parity, education, prepregnancy BMI, season, gestational age and neonate sex, maternal 25(OH)D was significantly associated with birth weight, head circumference, abdominal circumference and ponderal index (P<0·05 for all), when used as a continuous variable and categorised (consistently low, consistently high, increasing and decreasing level). However, after adjusting for ethnicity, 25(OH)D was no longer associated with any of the outcomes. Sex-specific associations for abdominal circumference and sum of skinfolds were found (P for interaction<0·05). In conclusion, in a multiethnic cohort of pregnant women with high prevalence of vitamin D deficiency, we found no independent relation between maternal vitamin D levels and any of the neonatal anthropometric measures, and the strong association between ethnicity and neonatal outcomes was not affected by maternal vitamin D status.

Ethnic differences in folic acid supplement use in a population-based cohort of pregnant women in Norway.

BACKGROUND: Peri-conceptional use of folic acid supplements is recommended to prevent neural tube defects. Correct supplement use seems to be less common among ethnic minorities. We examined ethnic differences in folic acid supplement use before and during pregnancy and possible effect modification by education or planning of pregnancy. METHODS: The participants were 811 healthy pregnant women from a population-based cohort study in Oslo, Norway in 2008-2010. Ethnicity was categorized to five groups (European, Middle Eastern, South Asian, East Asian, African). Data on folic acid supplement use were obtained from hospital records and remaining data by a questionnaire. Logistic regression analyses were adjusted for age, parity, planning of pregnancy, education and Norwegian language skills. RESULTS: Before pregnancy, 30.1% of European women and 7.1 to 13.6% of women in the other ethnic groups used folic acid supplements (p < 0.001). The adjusted odds ratio (OR) for supplement use was 0.55 (95% confidence interval 0.31; 0.96) for South Asian and 0.42 (95% confidence interval 0.19; 0.94) for Middle Eastern women compared with European women. During pregnancy, supplement use was most common in European women (65.7%) and least common in Middle Eastern (29.4%) and African women (29.0%) (p < 0.001). Compared with European women, all other ethnic groups had lower adjusted odds (OR 0.30 to 0.50, p < 0.05 for all) for supplement use among women with high school or less education, but not among more educated women. Planning of pregnancy did not modify the association between ethnicity and supplement use. CONCLUSIONS: Few women used folic acid supplements before pregnancy. Educational level modified the association between ethnicity and supplement use during pregnancy. Public health campaigns should focus on increasing awareness especially in ethnic minority groups with low educational level.

Objectively recorded physical activity in pregnancy and postpartum in a multi-ethnic cohort: association with access to recreational areas in the neighbourhood.

BACKGROUND: Physical activity may reduce the risk of adverse pregnancy outcomes; however, compared to non-pregnant women, a lower proportion of pregnant women meet the physical activity guidelines. Our objectives were to explore overall changes and ethnic differences in objectively recorded moderate-to-vigorous intensity physical activity (MVPA) during pregnancy and postpartum and to investigate the associations with objective and perceived access to recreational areas. METHODS: We analysed 1,467 person-observations from 709 women in a multi-ethnic population-based cohort, with MVPA data recorded with the SenseWear™ Pro(3) Armband in early pregnancy (mean gestational week (GW) 15), mid-pregnancy (mean GW 28) and postpartum (mean postpartum week 14). MVPA was limited to bouts ≥10 min. Women were nested within 56 neighbourhoods defined by postal code area. We derived neighbourhood-level objective access to recreational areas (good vs limited) by geographic information systems. We collected information about perceived access (high vs low perception) to recreational areas in early pregnancy. We treated ethnicity, objective and perceived access as explanatory variables in separate models based on linear mixed effects regression analyses. RESULTS: Overall, MVPA dropped between early and mid-pregnancy, followed by an increase postpartum. Western women performed more MVPA than women in other ethnic groups across time points, but the differences increased postpartum. Women residing in neighbourhoods with good objective access to recreational areas accumulated on average nine additional MVPA minutes/day (p < 0.01) compared with women in neighbourhoods with limited access. Women with perceptions of high access to recreational areas accumulated on average five additional MVPA minutes/day (p < 0.01) compared with women with perceptions of low access. After mutual adjustments, perceived and objective access to recreational areas remained significantly associated with MVPA. The association between MVPA and access to recreational areas did not differ by time point, ethnic group or socio-economic position. CONCLUSIONS: In all ethnic groups, we observed a decline in MVPA between early and mid-pregnancy. However, at both time points during pregnancy, and especially three months postpartum, Western women were more physically active than ethnic minority women. In all ethnic groups, and at all three time points, both objective and perceived access to recreational areas were positively associated with MVPA levels.

Vitamin D deficiency and supplementation in pregnancy in a multiethnic population-based cohort.

BACKGROUND: To investigate ethnic differences in vitamin D levels during pregnancy, assess risk factors for vitamin D deficiency and explore the effect of vitamin D supplementation in women with deficiency in early pregnancy. METHODS: This is a population-based, multiethnic cohort study of pregnant women attending Child Health Clinics for antenatal care in Oslo, Norway. Serum-25-hydroxyvitamin D [25(OH)D] was measured in 748 pregnant women (59% ethnic minorities) at gestational weeks (GW) 15 (SD:3.6) and 28 (1.4). Women with 25(OH)D <37 nmol/L at GW 15 were for ethical reasons recommended vitamin D3 supplementation. Main outcome measure was 25(OH)D, and linear regression models were performed. RESULTS: Severe deficiency (25(OH)D <25 nmol/L) was found at GW 15 in 45% of women from South Asia, 40% from the Middle East and 26% from Sub-Saharan Africa, compared to 2.5% in women from East Asia and 1.3% of women from Western Europe. Women from South Asia, the Middle East and Sub-Saharan Africa had mean values that were -28 (95 % CI:-33, -23), -24 (-29, -18) and -20 (-27, -13) nmol/L lower than in Western women, respectively. Ethnicity, education, season and intake of vitamin D were independently associated with 25(OH)D. At GW 28, the mean 25(OH)D had increased from 23 (SD:7.8) to 47 (27) nmol/L (p < 0.01) in women who were recommended vitamin D supplementation, with small or no change in women with sufficient vitamin D levels at baseline. CONCLUSIONS: Vitamin D deficiency was prevalent among South Asian, Middle Eastern and African women. The serum levels of 25(OH)D increased significantly from GW 15 to 28 in vitamin D deficient women who received a recommendation for supplementation. This recommendation of vitamin D supplementation increased vitamin D levels in deficient women.

Ethnic Differences in Gestational Weight Gain: A Population-Based Cohort Study in Norway.

Objectives To explore ethnic differences in gestational weight gain (GWG). Methods This was a population-based cohort study conducted in primary care child health clinics in Groruddalen, Oslo, Norway. Participants were healthy pregnant women (n = 632) categorised to six ethnic groups (43 % were Western European women, the reference group). Body weight was measured at 15 and 28 weeks' gestation on average. Data on pre-pregnancy weight and total GWG until delivery were self-reported. The main method of analysis was linear regression adjusting for age, weeks' gestation, pre-pregnancy body mass index, education and severe nausea. Results No ethnic differences were observed in GWG by 15 weeks' gestation. By 28 weeks' gestation, Eastern European women had gained 2.71 kg (95 % confidence interval, CI 1.10-4.33) and Middle Eastern women 1.32 kg (95 % CI 0.14-2.50) more weight on average than the Western European women in the fully adjusted model. Among Eastern European women, the total adjusted GWG was 3.47 kg (95 % CI 1.33-5.61) above the reference group. Other ethnic groups (South Asian, East Asian and African) did not differ from the reference group. When including non-smokers (n = 522) only, observed between-group differences increased and Middle Eastern women gained more weight than the reference group by all time points. Conclusions Eastern European and Middle Eastern women had higher GWG on average than Western European women, especially among the non-smokers. Although prevention of excessive GWG is important for all pregnant women, these ethnic groups might need special attention during pregnancy.

Effects of early pregnancy BMI, mid-gestational weight gain, glucose and lipid levels in pregnancy on offspring's birth weight and subcutaneous fat: a population-based cohort study.

BACKGROUND: Maternal glucose and lipid levels are associated with neonatal anthropometry of the offspring, also independently of maternal body mass index (BMI). Gestational weight gain, however, is often not accounted for. The objective was to explore whether the effects of maternal glucose and lipid levels on offspring's birth weight and subcutaneous fat were independent of early pregnancy BMI and mid-gestational weight gain. METHODS: In a population-based, multi-ethnic, prospective cohort of 699 women and their offspring, maternal anthropometrics were collected in gestational week 15 and 28. Maternal fasting plasma lipids, fasting and 2-hour glucose post 75 g glucose load, were collected in gestational week 28. Maternal risk factors were standardized using z-scores. Outcomes were neonatal birth weight and sum of skinfolds in four different regions. RESULTS: Mean (standard deviation) birth weight was 3491 ± 498 g and mean sum of skinfolds was 18.2 ± 3.9 mm. Maternal fasting glucose and HDL-cholesterol were predictors of birth weight, and fasting and 2-hour glucose were predictors of neonatal sum of skinfolds, independently of weight gain as well as early pregnancy BMI, gestational week at inclusion, maternal age, parity, smoking status, ethnic origin, gestational age and offspring's sex. However, weight gain was the strongest independent predictor of both birth weight and neonatal sum of skinfolds, with a 0.21 kg/week increased weight gain giving a 110.7 (95% confidence interval 76.6-144.9) g heavier neonate, and with 0.72 (0.38-1.06) mm larger sum of skinfolds. The effect size of mother's early pregnancy BMI on birth weight was higher in non-Europeans than in Europeans. CONCLUSIONS: Maternal fasting glucose and HDL-cholesterol were predictors of offspring's birth weight, and fasting and 2-hour glucose were predictors of neonatal sum of skinfolds, independently of weight gain. Mid-gestational weight gain was a stronger predictor of both birth weight and neonatal sum of skinfolds than early pregnancy BMI, maternal glucose and lipid levels.

A prospective cohort study of depression in pregnancy, prevalence and risk factors in a multi-ethnic population.

BACKGROUND: Depression in pregnancy increases the risk of complications for mother and child. Few studies are done in ethnic minorities. We wanted to identify the prevalence of depression in pregnancy and associations with ethnicity and other risk factors. METHOD: Population-based, prospective cohort of 749 pregnant women (59% ethnic minorities) attending primary antenatal care during early pregnancy in Oslo between 2008 and 2010. Questionnaires covering demographics, health problems and psychosocial factors were collected through interviews. Depression in pregnancy was defined as a sum score ≥ 10 by the Edinburgh Postnatal Depression Scale (EPDS) at gestational week 28. RESULTS: The crude prevalence of depression was; Western Europeans: 8.6% (95% CI: 5.45-11.75), Middle Easterners: 19.5% (12.19-26.81), South Asians: 17.5% (12.08-22.92), and other groups: 11.3% (6.09-16.51). Median EPDS score was 6 in Middle Easterners and 3 in all other groups. Middle Easterners (OR = 2.81; 95% CI (1.29-6.15)) and South Asians (2.72 (1.35-5.48)) had significantly higher risk for depression than other minorities and Western Europeans in logistic regression models. When adjusting for socioeconomic position and family structure, the ORs were reduced by 16-18% (OR = 2.44 (1.07-5.57) and 2.25 (1.07-4.72). Other significant risk factors were the number of recent adverse life events, self-reported history of depression and poor subjective health three months before conception. CONCLUSION: The prevalence of depression in pregnancy was higher in ethnic minorities from the Middle East and South Asia. The increased risk persisted after adjustment for risk factors.

Maternal life course socio-economic position and offspring body composition at birth in a multi-ethnic population.

BACKGROUND: Size and body composition at birth may affect long-term health. Mean birthweight and body composition differ between ethnic groups living in Europe. We wanted to explore if this relates to differences in socio-economic conditions in country of origin and over the maternal life course. METHODS: This is a population-based cohort study of healthy pregnant women living in Oslo, Norway. Data on maternal early life and present socio-economic position (SEP) were collected in early gestation, and SEP scores were extracted through two separate principal components analyses. The associations between maternal present SEP and four different offspring anthropometric measures at birth were assessed separately, stratified by maternal early life SEP (dichotomised score) and Human Development Index (HDI, a country-level socio-economic indicator) in the country of origin [high HDI (Reference), n = 287 and low HDI, n = 250]. RESULTS: A strong positive association between maternal present SEP and offspring birthweight was observed if maternal early life SEP was high, but not if maternal early life SEP was low (P < 0.001 for the interaction term). This interactional effect was observed in both HDI groups. Maternal life course SEP affected offspring birthweight mainly through an effect on length and sum of skin folds. Offspring of mothers with origin from low HDI countries had smaller abdominal circumference, possibly indicating less fat-free mass, regardless of maternal life course SEP. CONCLUSION: Our results suggest that there are transgenerational effects of maternal past socio-economic conditions on offspring size and body composition at birth that modify the associations with present socio-economic factors.

Urine NMR metabolomics analysis of breastfeeding biomarkers during and after pregnancy in a large prospective cohort study.

BACKGROUND: Modern metabolomic profiling has not yet been applied to human breastfeeding research. A common reason for breastfeeding cessation is perceived insufficient milk production. We investigated broad biochemical profiles in maternal urine collected during and after pregnancy to identify biomarkers related to reduced reported breastfeeding. METHODS: Fasting urine was collected at three consultations (visit V1: gestational week 8-20; V2: week 28 ± 2; V3: 10-16 weeks postpartum) in the STORK Groruddalen program, a prospective, multiethnic cohort study of gestational diabetes involving healthy, pregnant women in Oslo, Norway, and analyzed using NMR spectroscopy. Breastfeeding at V3 was recorded in three categories: Exclusively breastfeeding (n = 326), partially breastfeeding (n = 156) and formula feeding (n = 67). RESULTS: Five metabolites were relevant to breastfeeding. Lactose was detected at V1 and increased to 0.1 mM/mM creatinine at V2. Postpartum excretion at V3 was significantly higher in exclusively breastfeeding women than partially or non-breastfeeding (median = 0.29, 0.23 and 0.04 mM/mM creatine, respectively; ANOVA p-value = 2e-70). Glycine excretion at V3 (0.12, 0.10 and 0.06, respectively; p = 2e-5) and at V2 were associated with breastfeeding (0.34, 0.33 and 0.26, respectively; p = 4e-5). Creatine and two unidentified substances also correlated with breastfeeding. NMR metabolomics found no other metabolites differing between categories during pregnancy (V1, V2), and did not predict individual breastfeeding postpartum (V3). CONCLUSION: Decreased glycine excretion at V2 may indicate difficulties meeting the metabolic demands of the growing fetus, but urine profiles contained otherwise little indication of early adaptations during pregnancy towards reduced biological potential to breastfeed.