Serum Zinc Concentrations by Inflammation Status, Time of Day, and Fasting Status for Estimating Zinc Deficiency in 6-59-Mo-Old Children: Results from the Brazilian National Survey on Child Nutrition (ENANI-2019).

BACKGROUND: Serum zinc concentration (SZC) is considered the best biomarker of zinc status in population-level evaluations. However, zinc deficiency (ZD) estimations can be biased if they do not consider blood collection timing, inflammation, and fasting status. OBJECTIVES: The objectives of this study were to determine SZC without and with adjustment for inflammation, according to blood collection timing and fasting status, estimate ZD prevalence, and evaluate the associated factors with ZD in a representative sample of Brazilian children aged <5 y. METHODS: Population-based study with 7597 children aged 6-59 mo surveyed by the Brazilian National Survey on Child Nutrition. SZC was adjusted for inflammation using the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia regression correction approach, with high-sensitive C-reactive protein, assessed according to blood collection timing (morning/afternoon) and fasting status (<8 and ≥8 h). SZC <65 µg/dL (morning collection) or SZC <57 µg/dL (afternoon collection) were classified as ZD. The analysis between associated factors and ZD used the adjusted prevalence ratio (PR). RESULTS: After adjusting for inflammation, SZC was higher in all percentiles and varied according to collection timing and fasting status. Children who had blood collected in the morning without fasting or in the afternoon had lower SZC than those assessed in the morning with fasting. The differences in adjusted SZC according to the timing of collection and fasting status were greater in the higher percentiles of the distribution, with the greatest absolute difference observed when comparing the 95th percentile of morning fasting compared with nonfasting (20.3 µg/dL). The prevalence of ZD estimated without and with adjusting SZC for inflammation was 17.8% and 13.8%, respectively. The occurrence of diarrhea, fever, or respiratory symptoms in the 15 d before blood collection was associated with a higher prevalence of ZD (PR: 1.42; 95% confidence interval: 1.04, 1.94). CONCLUSIONS: Adjusting SZC for inflammation and considering fasting status is important to avoid overestimating the prevalence of ZD.

Prevalence and predictors of vitamin D insufficiency in Brazilian children under 5 years of age: Brazilian National Survey on Child Nutrition (ENANI-2019).

To analyse the association of socio-demographic and health factors with vitamin D insufficiency and 25-hydroxyvitamin D (25(OH)D) concentration in Brazilian children aged 6-59 months. Data from 8145 children from the Brazilian National Survey on Child Nutrition (ENANI-2019) were analysed. The serum concentration of 25(OHD)D was measured using a chemiluminescent immunoassay. The prevalence of vitamin D insufficiency (25(OH)D < 50 nmol/l) and 95 % CI was calculated. Logistic and linear regression models were used to identify the variables associated with vitamin D insufficiency and serum 25(OH)D concentrations, respectively. The mean 25(OH)D concentration was 98·6 ± 36·0 nmol/l, and 4·3 % of the children presented vitamin D insufficiency. Children aged 6-23 months (OR = 2·23; 95 % CI 1·52, 3·26); belonging to Southeast (OR = 5·55; 95 % CI 2·34, 13·17) and South (OR = 4·57; 95 % CI 1·77, 11·84) regions; the second tertile of the National Wealth Score (OR = 2·14; 95 % CI 1·16, 3·91) and winter (OR = 5·82; 95 % CI 2·67, 12·71) and spring (OR = 4·84; 95 % CI 2·17, 10·80) seasons of blood collection were associated with a higher chance of vitamin D insufficiency. Female sex (ß = -5·66, 95 % CI - 7·81, -3·51), urban location (ß = -14·19, 95 % CI -21·0, -7·22) and no vitamin D supplement use (ß = -6·01, 95 % CI -9·64, -2·39) were inversely associated with serum 25(OH)D concentration. The age of children and the Brazilian geographical region of household location were the main predictors of vitamin D insufficiency. In Brazil, vitamin D insufficiency among children aged 6-59 months is low and is not a relevant public health problem.

Identifying biologically implausible values in big longitudinal data: an example applied to child growth data from the Brazilian food and nutrition surveillance system.

BACKGROUND: Several strategies for identifying biologically implausible values in longitudinal anthropometric data have recently been proposed, but the suitability of these strategies for large population datasets needs to be better understood. This study evaluated the impact of removing population outliers and the additional value of identifying and removing longitudinal outliers on the trajectories of length/height and weight and on the prevalence of child growth indicators in a large longitudinal dataset of child growth data. METHODS: Length/height and weight measurements of children aged 0 to 59 months from the Brazilian Food and Nutrition Surveillance System were analyzed. Population outliers were identified using z-scores from the World Health Organization (WHO) growth charts. After identifying and removing population outliers, residuals from linear mixed-effects models were used to flag longitudinal outliers. The following cutoffs for residuals were tested to flag those: -3/+3, -4/+4, -5/+5, -6/+6. The selected child growth indicators included length/height-for-age z-scores and weight-for-age z-scores, classified according to the WHO charts. RESULTS: The dataset included 50,154,738 records from 10,775,496 children. Boys and girls had 5.74% and 5.31% of length/height and 5.19% and 4.74% of weight values flagged as population outliers, respectively. After removing those, the percentage of longitudinal outliers varied from 0.02% (<-6/>+6) to 1.47% (<-3/>+3) for length/height and from 0.07 to 1.44% for weight in boys. In girls, the percentage of longitudinal outliers varied from 0.01 to 1.50% for length/height and from 0.08 to 1.45% for weight. The initial removal of population outliers played the most substantial role in the growth trajectories as it was the first step in the cleaning process, while the additional removal of longitudinal outliers had lower influence on those, regardless of the cutoff adopted. The prevalence of the selected indicators were also affected by both population and longitudinal (to a lesser extent) outliers. CONCLUSIONS: Although both population and longitudinal outliers can detect biologically implausible values in child growth data, removing population outliers seemed more relevant in this large administrative dataset, especially in calculating summary statistics. However, both types of outliers need to be identified and removed for the proper evaluation of trajectories.

Risk factors for inadequate and excessive gestational weight gain in 25 low- and middle-income countries: An individual-level participant meta-analysis.

BACKGROUND: Many women experience suboptimal gestational weight gain (GWG) in low- and middle-income countries (LMICs), but our understanding of risk factors associated with GWG in these settings is limited. We investigated the relationships between demographic, anthropometric, lifestyle, and clinical factors and GWG in prospectively collected data from LMICs. METHODS AND FINDINGS: We conducted an individual participant-level meta-analysis of risk factors for GWG outcomes among 138,286 pregnant women with singleton pregnancies in 55 studies (27 randomized controlled trials and 28 prospective cohorts from 25 LMICs). Data sources were identified through PubMed, Embase, and Web of Science searches for articles published from January 2000 to March 2019. Titles and abstracts of articles identified in all databases were independently screened by 2 team members according to the following eligibility criteria: following inclusion criteria: (1) GWG data collection took place in an LMIC; (2) the study was a prospective cohort or randomized trial; (3) study participants were pregnant; and (4) the study was not conducted exclusively among human immunodeficiency virus (HIV)-infected women or women with other health conditions that could limit the generalizability of the results. The Institute of Medicine (IOM) body mass index (BMI)-specific guidelines were used to determine the adequacy of GWG, which we calculated as the ratio of the total observed weight gain over the mean recommended weight gain. Study outcomes included severely inadequate GWG (percent adequacy of GWG <70), inadequate GWG (percent adequacy of GWG <90, inclusive of severely inadequate), and excessive GWG (percent adequacy of GWG >125). Multivariable estimates from each study were pooled using fixed-effects meta-analysis. Study-specific regression models for each risk factor included all other demographic risk factors measured in a particular study as potential confounders, as well as BMI, maternal height, pre-pregnancy smoking, and chronic hypertension. Risk factors occurring during pregnancy were further adjusted for receipt of study intervention (if any) and 3-month calendar period. The INTERGROWTH-21st standard was used to define high and low GWG among normal weight women in a sensitivity analysis. The prevalence of inadequate GWG was 54%, while the prevalence of excessive weight gain was 22%. In multivariable models, factors that were associated with a higher risk of inadequate GWG included short maternal stature (<145 cm), tobacco smoking, and HIV infection. A mid-upper arm circumference (MUAC) of ≥28.1 cm was associated with the largest increase in risk for excessive GWG (risk ratio (RR) 3.02, 95% confidence interval (CI) [2.86, 3.19]). The estimated pooled difference in absolute risk between those with MUAC of ≥28.1 cm compared to those with a MUAC of 24 to 28.09 cm was 5.8% (95% CI 3.1% to 8.4%). Higher levels of education and age <20 years were also associated with an increased risk of excessive GWG. Results using the INTERGROWTH-21st standard among normal weight women were similar but attenuated compared to the results using the IOM guidelines among normal weight women. Limitations of the study's methodology include differences in the availability of risk factors and potential confounders measured in each individual dataset; not all risk factors or potential confounders of interest were available across datasets and data on potential confounders collected across studies. CONCLUSIONS: Inadequate GWG is a significant public health concern in LMICs. We identified diverse nutritional, behavioral, and clinical risk factors for inadequate GWG, highlighting the need for integrated approaches to optimizing GWG in LMICs. The prevalence of excessive GWG suggests that attention to the emerging burden of excessive GWG in LMICs is also warranted.

High Serum Folate Concentration, Vitamin B12 Deficiency, and Anthropometric Nutritional Status in Brazilian Children Aged 6-59 Months: Data from the Brazilian National Survey of Child Nutrition.

BACKGROUND: Vitamin B12 and folate are key nutrients that help children reach their full potential in growth and development; however, little is known about the status of these vitamins in Brazilian children. OBJECTIVES: To describe the serum concentrations of vitamin B12 and folate, to investigate the association between high folate concentration (HFC) and vitamin B12 deficiency, and to evaluate the association between vitamin B12 and stunting/underweight in Brazilian children aged 6-59 mo. METHODS: Data from 7417 children aged 6-59 mo collected during the Brazilian National Survey on Child Nutrition were used. Serum concentrations of vitamin B12 of <150 pmol/L and folate of <10 nmol/L were classified as deficient, and folate concentrations of >45.3 nmol/L were classified as HFC. Children with length/height-for-age z-score of less than -2 were considered stunted, and those with weight-for-age z-score of less than -2 were underweight. Logistic regression models were performed. RESULTS: In Brazil, 14.2% (95% CI: 12.2, 16.1) of children aged 6-59 mo had vitamin B12 deficiency, 1.1% (95% CI: 0.5, 1.6) had folate deficiency, and 36.9% (95% CI: 33.4, 40.3) had HFC. Vitamin B12 deficiency was higher in children from the northern region of Brazil (28.5%), between 6 and 24 mo (25.3%), whose mothers had lower formal education (0-7 y; 18.7%). Children with HFC had 62% lower odds (OR: 0.38; 95% CI: 0.27, 0.54) of vitamin B12 deficiency than those with normal/deficient folate. Children with vitamin B12 deficiency and normal/deficient folate had higher odds of stunting (OR: 1.58; 95% CI: 1.02, 2.43) than children without vitamin B12 deficiency and normal/deficient folate. CONCLUSIONS: Vitamin B12 deficiency is a public health problem among Brazilian children aged <2 y with vulnerable socioeconomic status. HFC was inversely associated with vitamin B12 deficiency, and lower odds of stunting were observed in children with HFC and vitamin B12 deficiency than in those with vitamin B12 deficiency and normal/deficient folate.

Prepregnancy Body Mass Index and Lipoprotein Fractions are Associated with Changes in Women's Serum Metabolome from Late Pregnancy to the First Months of Postpartum.

BACKGROUND: Pregnancy and postpartum are periods of intense changes in women's metabolism. The knowledge of the metabolites and maternal factors underlying these changes is limited. OBJECTIVES: We aimed to investigate the maternal factors that could influence serum metabolome changes from late pregnancy to the first months of postpartum. METHODS: Sixty-eight healthy women from a Brazilian prospective cohort were included. Maternal blood and general characteristics were collected during pregnancy (28-35 wk) and postpartum (27-45 d). A targeted metabolomics approach was applied to quantify 132 serum metabolites, including amino acids, biogenic amines, acylcarnitines, lysophosphatidylcholines (LPC), diacyl phosphatidylcholines (PC), alkyl:acyl phosphatidylcholines (PC-O), sphingomyelins with (SM) and without hydroxylation [SM(OH)], and hexoses. Metabolome changes from pregnancy to postpartum were measured as log2 fold change (log2FC), and simple linear regressions were employed to evaluate associations between maternal variables and metabolite log2FC. Multiple comparison-adjusted P values of < 0.05 were considered significant. RESULTS: Of 132 metabolites quantified in serum, 90 changed from pregnancy to postpartum. Most metabolites belonging to PC and PC-O classes decreased, whereas most LPC, acylcarnitines, biogenic amines, and a few amino acids increased in postpartum. Maternal prepregnancy body mass index (ppBMI) showed positive associations with leucine and proline. A clear opposite change pattern was observed for most metabolites across ppBMI categories. Few phosphatidylcholines were decreased in women with normal ppBMI, while an increase was observed in women with obesity. Similarly, women with high postpartum levels of total cholesterol, LDL cholesterol, and non-HDL cholesterol showed increased sphingomyelins, whereas a decrease was observed for women with lower levels of those lipoproteins. CONCLUSIONS: The results revealed several maternal serum metabolomic changes from pregnancy to postpartum, and the maternal ppBMI and plasma lipoproteins were associated with these changes. We highlight the importance of the nutritional care of women prepregnancy to improve their metabolic risk profile.

Prevalence and temporal trends in prepregnancy nutritional status and gestational weight gain of adult women followed in the Brazilian Food and Nutrition Surveillance System from 2008 to 2018.

Prepregnancy body mass index (BMI) and gestational weight gain (GWG) are the most investigated indicators of maternal nutritional status, which is a modifiable factor that plays a vital role in maternal and infant health. This study describes prepregnancy BMI and GWG of 840,243 women with 2,087,765 weight observations in the Brazilian Food and Nutrition Surveillance System from 2008 to 2018. Prepregnancy BMI was classified according to the World Health Organization cut-offs. Total GWG was calculated from weight measurements taken after 36 weeks of pregnancy and classified according to the Institute of Medicine guidelines. Temporal trends in prepregnancy BMI status were examined, and maps were used to evaluate changes in excessive GWG in each Brazilian federation unit. On overall, prepregnancy overweight and obesity increased from 22.6% to 28.8% and from 9.8% to 19.8%, respectively, between 2008 and 2018. The prevalence of excessive GWG rose from 34.2% to 38.7% during the same period and in 11 of the 27 Brazilian federation units between 2008 and 2016. Women with underweight showed the highest values for mean total GWG for all the compared years (overall variation from 12.3 to 13.1 kg), followed by those with normal weight (11.9 to 12.5 kg), overweight (10.1 to 10.9 kg) and obesity (from 8.2 to 8.9 kg). Within each BMI group, values remained fairly stable throughout the studied period for first- and second-trimester GWG and total GWG. These results help to fill a significant gap in understanding the distribution of prepregnancy BMI and GWG in Brazilian women.

Associations Between Human Milk Oligosaccharides at 1 Month and Infant Development Throughout the First Year of Life in a Brazilian Cohort.

BACKGROUND: Human milk oligosaccharides (HMOs) are unconjugated glycans associated with infant health and development. OBJECTIVES: To investigate the associations between HMO concentrations at 1 month and infant development throughout the first year of life. METHODS: A prospective cohort of Brazilian women between 18-40 years of age and their infants was studied from baseline (between 28-35 gestational weeks) and followed at 1 (n = 73), 6 (n = 51), and 12 months (n = 45). A total of 19 HMOs were quantified by HPLC with fluorescence detection. Infant development was evaluated by the Brazilian Ages and Stages Questionnaire. A directed acyclic graph was used to define the minimally sufficient adjustment (gestational age at birth, gestational weight gain, prepregnancy BMI, maternal age, parity, and the mode of breastfeeding at 1 month). Cox regression models with HRs and Benjamini-Hochberg multiple corrections were performed to estimate associations of HMOs with the cumulative risk of inadequate development for 5 developmental domains or for ≥2 developmental domains in all women and in the subset of secretor women (defined as the presence or near absence of 2'-fucosyllactose and lacto-N-fucopentaose I). RESULTS: The multivariate models with multiple corrections revealed an inverse association between lacto-N-tetrose (LNT) and the risk of inadequate development for personal-social skills (0.06; 95% CI: 0.01-0.76) and for ≥2 developmental domains (0.06; 95% CI: 0.01-0.59). The secretor mothers analysis also showed inverse associations with slightly different results for personal-social skills (0.09; 95% CI: 0.02-0.84) and ≥2 developmental domains (0.05; 95% CI: 0.01-0.70). CONCLUSIONS: Higher concentrations of LNT HMOs in Brazilian women are associated with their infants being less likely to be at risk of inadequate development for personal-social skills or for ≥2 developmental domains during the first year of life.

Adiponectin and leptin gene variants and their effects on body weight trajectories in children from birth to 6 years of age: the PREDI Study.

Excess body weight confers a high risk to human health. Body weight variation between subjects can be partially explained by genetic differences. The aim of the present study was to investigate the association of genetic variants in the ADIPOQ (rs2241766) and LEP (rs7799039) genes with body weight trajectories in children from birth to 6 years of age. This was a prospective cohort (PREDI Study). Socio-economic, biological and anthropometric data were collected at four time points: at birth in the maternity unit; 1-2, 4-5 and 6 years old at the participants' homes. Genotyping was performed by PCR-restriction fragment length polymorphism. Poisson regression and linear mixed-effect regression models were used to address the association of ADIPOQ and LEP genotypes with BMI. Excessive body weight at pre-pregnancy (ß = 0·339, P = 0·01) and excessive gestational weight gain (ß = 0·51, P < 0·001) were associated with children's BMI trajectory from birth to 6 years. The ADIPOQ-rs2241766 TG or GG genotype was associated with a higher risk of excess body weight in the first 6 years of life (both sexes relative risk 1·25, 95 % CI 1·01, 1·56; female relative risk 1·67, 95 % CI 1·20, 2·31). BMI increased over the years according to the presence of the TG or GG genotype (ß = 0·01, 95 % CI 0·01, 0·02), particularly in females (ß = 0·02, 95 % CI 0·01, 0·04). The ADIPOQ-rs2241766 TG and GG genotypes increased the risk of excess body weight in children from birth to 6 years of age and had a positive effect on body weight trajectories in girls. The LEP-rs7799039 genetic variant was not associated with body weight trajectory in children.

Intergenerational breastfeeding practices among parents and children: 1993 Pelotas (Brazil) birth cohort.

The objective of this study was to investigate intergenerational breastfeeding practices according to parental sex and age at delivery in the 1993 Pelotas (Brazil) birth cohort study. This is a prospective birth cohort study, and at the 22-year follow-up, a substudy with all children of the cohort members who had become parents was conducted (93Cohort-II). First generation breastfeeding data were collected at 3 months and 4-year-old follow-ups. In the 93Cohort-II, parents answered a questionnaire about their children's breastfeeding practices. Adjusted Tobit and Poisson regression models with robust variance were applied to estimate the association between predominant parental breastfeeding duration and exclusive breastfeeding duration of the children at 3 and 6 months. Out of 3,810 cohort participants, 955 (25%) had delivered at least one live-born infant, and 1,222 children were assessed. Fifty-four percent of parents were ≤19 years old. Direct effects of predominant parental breastfeeding duration on exclusive breastfeeding duration of their children were only observed when data were stratified by parental age: children born to parents aged ≥20 years old and who were predominantly breastfed for at least 3 months presented higher exclusive breastfeeding duration and higher prevalence of being exclusively breastfed for at least 3 months. When analyses were stratified by mothers and fathers, the result remained significant only among mothers. Longer predominant breastfeeding duration in the first generation was associated with longer exclusive breastfeeding duration in the second generation, but only among older mothers. Education and social support surrounding breastfeeding should be intensified among fathers and younger parents to create a positive environment supportive of breastfeeding.

Leptin gene polymorphism (rs7799039; G2548A) is associated with changes in serum lipid concentrations during pregnancy: a prospective cohort study.

PURPOSE: Little is known about the effects of leptin and leptin receptor polymorphisms on lipid changes during pregnancy. The aims of this study were to evaluate the associations between the single nucleotide polymorphisms (SNPs) of leptin and leptin receptor genes and the lipid concentrations during pregnancy; and to test whether dietary intake is a mediator in these associations. METHODS: A prospective cohort of 154 pregnant women was followed up in Rio de Janeiro, Brazil during the following gestational periods: 5-13th, 20-26th and 30-36th weeks. HDL-C, total cholesterol (TC) and triglyceride (TG) were measured by the enzymatic colorimetric method, and LDL-C was calculated. DNA was extracted by the phenol-chloroform method, and leptin (G2548A, rs7799039) and leptin receptor SNPs (Q223R; rs1137101 and K109R; rs1137100) were genotyped using real-time PCR. Statistical analyses included linear mixed-effect models. RESULTS: Women with the AA genotype of G2548A polymorphism reported a higher fat and total energy intake and had a higher increase in TG concentration during pregnancy than women with AG or GG genotype. The association between G2548A SNP and TG concentrations was not attenuated by adjusting for total lipid (g) and energy (kcal) intake. We did not observe significant associations between the Q223R and K109R SNPs and the lipid concentrations. CONCLUSIONS: Women homozygous for the A allele of the leptin SNP (G2548A) had a higher increase in TG concentrations per gestational week compared with women with the AG or GG genotype. This is an exploratory and hypothesis-generating study, and the results need confirmation in studies with larger sample sizes.'

Agreement between self-reported pre-pregnancy weight and measured first-trimester weight in Brazilian women.

BACKGROUND: Self-reported pre-pregnancy weight and weight measured in the first trimester are both used to estimate pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) but there is limited information on how they compare, especially in low- and middle-income countries, where access to a weight scale can be limited. Thus, the main goal of this study was to evaluate the agreement between self-reported pre-pregnancy weight and weight measured during the first trimester of pregnancy among Brazilian women so as to assess whether self-reported pre-pregnancy weight is reliable and can be used for calculation of BMI and GWG. METHODS: Data from the Brazilian Maternal and Child Nutrition Consortium (BMCNC, n = 5563) and the National Food and Nutritional Surveillance System (SISVAN, n = 393,095) were used to evaluate the agreement between self-reported pre-pregnancy weight and weights measured in three overlapping intervals (30-94, 30-60 and 30-45 days of pregnancy) and their impact in BMI classification. We calculated intraclass correlation and Lin's concordance coefficients, constructed Bland and Altman plots, and determined Kappa coefficient for the categories of BMI. RESULTS: The mean of the differences between self-reported and measured weights was < 2 kg during the three intervals examined for BMCNC (1.42, 1.39 and 1.56 kg) and about 1 kg for SISVAN (1.0, 1.1 and 1.2 kg). Intraclass correlation and Lin's coefficient were > 0.90 for both datasets in all time intervals. Bland and Altman plots showed that the majority of the difference laid in the ±2 kg interval and that the differences did not vary according to measured first-trimester BMI. Kappa coefficient values were > 0.80 for both datasets at all intervals. Using self-reported pre-pregnancy or measured weight would change, in total, the classification of BMI in 15.9, 13.5, and 12.2% of women in the BMCNC and 12.1, 10.7, and 10.2% in the SISVAN, at 30-94, 30-60 and 30-45 days, respectively. CONCLUSION: In Brazil, self-reported pre-pregnancy weight can be used for calculation of BMI and GWG when an early measurement of weight during pregnancy is not available. These results are especially important in a country where the majority of woman do not initiate prenatal care early in pregnancy.

Maternal Plasma Pyridoxal 5'-Phosphate Concentration Is Inversely Associated with Plasma Cystathionine Concentration across All Trimesters in Healthy Pregnant Women.

BACKGROUND: Vitamin B-6 (B-6), in the form of pyridoxal 5'phosphate (PLP), is critical for one-carbon metabolism reactions and cellular function. Plasma PLP concentration decreases throughout pregnancy, but the functional consequences of this have not been studied. Plasma cystathionine is a sensitive indicator of suboptimal B-6 status in healthy adults. OBJECTIVES: The aim of this study was to determine the relation between plasma PLP and cystathionine concentrations, and to assess longitudinal changes in plasma concentrations of metabolites of one-carbon metabolism, including total homocysteine (tHcy), cysteine, methionine, glycine, serine, and glutathione, over the course of pregnancy. DESIGN: This was a prospective cohort study of 186 healthy Brazilian pregnant women (20-40 y). Plasma PLP and metabolite concentrations were quantified in fasting maternal blood samples collected between 5-13, 20-26, and 30-36 weeks of gestation. Linear mixed regression models were used to determine the association of 1) first-trimester PLP tertiles, and 2) the variation of PLP concentration throughout pregnancy, with related metabolite concentrations across weeks of gestation. RESULTS: Median (IQR) PLP concentration decreased from 36.2 (29.2-44.5) to 21.0 (15.9-26.0) to 16.8 (12.9-21.4) nmol/L in the first, second, and third trimester, respectively, whereas cystathionine concentration increased from 63.2 (49.7-78.9) to 122 (98.0-167) to 143 (114-193) nmol/L, respectively (both P < 0.001). The variation of PLP throughout pregnancy was inversely associated with cystathionine concentration across weeks of gestation, after adjusting for confounding factors; ß (95% CI) = -0.387 (-0.752, -0.219), P = 0.04. This association significantly differed by trimester and was strongest in the third trimester. Plasma concentrations of glycine, serine, methionine, cysteine, and tHcy decreased, and that of glutathione increased, between the first and second trimesters (all P < 0.05). CONCLUSIONS: The variation of PLP concentration predicted cystathionine concentration throughout pregnancy. Increases in plasma cystathionine across trimesters may reflect maternal intracellular B-6 deficiency.

Longitudinal association of 25-hydroxyvitamin D with adipokines and markers of glucose metabolism among Brazilian pregnant women.

This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, homoeostatic model assessment of insulin resistance, adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th-13th, 20th-26th and 30th-36th gestational weeks. In this cohort, 25-hydroxyvitamin D (25(OH)D) plasma concentrations were analysed using liquid chromatography-tandem MS. Vitamin D status was categorised as sufficient or insufficient using the Endocrine Society Practice Guidelines (≥75/<75 nmol/l) and the Institute of Medicine (≥50/<50 nmol/l) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering interaction terms between vitamin D status and gestational age (P<0·1). At baseline, 70·7 % of pregnant women had 25(OH)D levels <75 nmol/l and 16 % had levels <50 nmol/l. Women with sufficient vitamin D status at baseline, using both thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/l showed lower insulin (ß=-0·12; 95 % CI -0·251, 0·009; P=0·069) and adiponectin (ß=-0·070; 95 % CI -0·150, 0·010; P=0·085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/l. Pregnant women with 25(OH)D <50 nmol/l at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/l (ß=-0·253; 95 % CI -0·044, 0·550; P=0·095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D-sufficient women at baseline had higher increases in insulin and adiponectin changes throughout gestation than those who were insufficient.

Gestational weight gain and newborn anthropometric outcomes in rural Bangladesh.

Low gestational weight gain (GWG) is a known predictor of fetal growth restriction in higher income countries, but there is little information on this association in lower income countries. Our objective is to describe the association between GWG and birth outcomes among pregnant women in rural Bangladesh. Pregnant women were identified in a community-based programme and enrolled into the study at an average of 13 weeks' gestation (n = 4,011). Maternal weight and height were measured at enrolment, maternal weight was measured at 36 weeks' gestation, and newborns were measured after birth. Rate of GWG (g/weeks) was calculated, and women were categorized as having adequate or inadequate GWG (Institute of Medicine recommendations). Newborn anthropometric outcomes included weight-for-age z score (WAZ), length-for-age z score (LAZ), head-circumference-for-age z score (HCZ), body mass index (BMI)-for-age z score (BMIZ), low birthweight (LBW < 2,500 g), WAZ < -2, LAZ < -2, HCZ < -2, BMIZ < -2, and small for gestational age (SGA: <10th percentile). Multivariate models were adjusted for confounders. Only 26% of the 2,562 women in these analyses had adequate GWG. Compared with newborns of women with inadequate GWG, infants of women with adequate GWG had a lower risk of adverse anthropometric outcomes (relative risk [95% confidence interval]: LBW = 0.68 [0.59, 0.80], LAZ < -2 = 0.64 [0.51, 0.80], HCZ < -2 = 0.75 [0.60, 0.93], BMIZ < -2 = 0.70 [0.59, 0.83], and SGA = 0.80 [0.73, 0.86]), but there was no significant difference in mean (SE) duration of gestation, 39.7 (0.08) versus 39.7 (0.05) weeks. In this population, GWG rate is a strong predictor of newborn anthropometric outcomes, but not duration of gestation.

High protein diet promotes body weight loss among Brazilian postpartum women.

There is evidence in the general population that adhering to a high protein and low carbohydrate diet may help in losing weight. However, there is little evidence among postpartum women. The aim of this study is to evaluate the effect of a high protein diet on weight loss among postpartum women. A parallel-randomized controlled trial with 94 postpartum women was conducted in a maternity ward in Mesquita county (recruitment from February 2009 to December 2010) and in a polyclinic in Rio de Janeiro city (recruitment from December 2010 to December 2011). Women were randomized to the intervention group (IG) or control group (CG), and both groups received an isocaloric diet (1,800 kcal). Additionally, the IG received approximately 25 g of protein obtained from 125 g per week of sardine to increase daily dietary protein content and was advised to restrict carbohydrate intake. The CG received nutritional counselling to follow the national nutrition guidelines (15% protein, 60% carbohydrates, and 25% lipids). A linear mixed-effects model was used to test the effect of high protein intake and macronutrient intake on weight loss during the postpartum period. Body weight decreased in the IG compared with the CG (ß = -0.325; p = 0.049) among overweight and obese postpartum women. The percentage of energy intake from lipid (ß = -0.023; p = 0.050) was negatively associated with body weight, and carbohydrate intake (ß = 0.020; p = 0.026) was positively associated with body weight over time among all women. Protein intake and lower carbohydrate intake may be used as a dietary strategy to improve body weight loss during the postpartum period.

Dietary patterns and their association with adiponectin and leptin concentrations throughout pregnancy: a prospective cohort.

The aim of this study was to evaluate the association of dietary patterns (DP) with maternal adiposity indicators, leptin, adiponectin and insulin concentrations during pregnancy. A prospective cohort of pregnant women followed up at the 5th-13th, 20th -26th and 30th-36th gestational weeks and 30-40 d postpartum was conducted in Rio de Janeiro. A FFQ was administered in the third trimester (30th-36th gestational weeks). The reduced rank regression procedure was used to identify DP that explain response variables (dietary fibre and total fat) related to indicators of maternal adiposity (postpartum weight retention and gestational weight gain (GWG) adequacy), and plasma leptin, adiponectin and insulin concentrations. The associations between tertiles of DP and the outcomes were determined using logistic regression or longitudinal linear mixed-effect regression models. The mean daily energy intake during pregnancy was 10 104 (sd 3234) kJ (2415 (sd 773) kcal), and GWG was 11·9 (sd 4·2) kg. In all, 40 % of women presented pre-gestational overweight/obesity. Excessive GWG occurred in 34·7 % of pregnant women and 56·6 % were overweight/obese at postpartum. The 'common-Brazilian' DP (characterised by higher intake of beans, rice and lower intake of fast food/snacks, candies/table sugar and processed meats/bacon) was positively associated with adiponectin (ß=1·07; 95 % CI 0·17, 1·98). The 'Western' DP (characterised by higher intake of fast food/snacks and processed meat/bacon and lower intake of noodles/pasta/roots/tubers and sodas) was negatively associated with adiponectin (ß=-1·11; 95 % CI -2·00, -0·22) and positively associated with leptin concentrations (ß=64·9; 95 % CI 22·8, 107·0) throughout pregnancy. It may be suggested that the 'common-Brazilian' is a healthy DP and beneficial for serum concentrations of adiponectin and leptin.

Associations between obesity candidate gene polymorphisms (fat mass and obesity-associated (FTO), melanocortin-4 receptor (MC4R), leptin (LEP) and leptin receptor (LEPR)) and dietary intake in pregnant women.

Genetic variants associated with dietary intake may be important as factors underlying the development of obesity. We investigated the associations between the obesity candidate genes (fat mass and obesity-associated (FTO), melanocortin-4 receptor (MC4R), leptin (LEP) and leptin receptor) and total energy intake and percentage of energy from macronutrients and ultra-processed foods before and during pregnancy. A sample of 149 pregnant women was followed up in a prospective cohort in Rio de Janeiro, Brazil. A FFQ was administered at 5-13 and 30-36 weeks of gestation. Genotyping was performed using real-time PCR. Associations between polymorphisms and the outcomes were investigated through multiple linear regression and ANCOVA having pre-pregnancy dietary intake as a covariate. The A-allele of FTO-rs9939609 was associated with a -6·5 % (95 % CI -12·3, -0·4) decrease in the percentage of energy from protein and positively associated with the percentage of energy from carbohydrates before pregnancy (ß=2·6; 95 % CI 0·5, 4·8) and with a 13·3 % (95 % CI 0·7, 27·5) increase in the total energy intake during pregnancy. The C-allele of MC4R-rs17782313 was associated with a -7·6 % (95 % CI -13·8, -1·0) decrease in the percentage of energy from protein, and positively associated with the percentage of energy from ultra-processed foods (ß=5·4; 95 % CI 1·1, 9·8) during pregnancy. ANCOVA results revealed changes in dietary intake from pre-pregnancy to pregnancy for FTO-rs9939609 (percentage of energy from ultra-processed foods, P=0·03), MC4R-rs17782313 (total energy intake, P=0·02) and LEP-rs7799039 (total energy intake, P=0·04; percentage of energy from protein, P=0·04). These findings suggest significant associations between FTO-rs9939609, MC4R-rs17782313 and LEP-rs7799039 genes and the components of dietary intake in pregnant women.

Changes in plasma concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D during pregnancy: a Brazilian cohort.

PURPOSE: To characterize the physiological changes in 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] throughout pregnancy. METHODS: Prospective cohort of 229 apparently healthy pregnant women followed at 5th-13th, 20th-26th, and 30th-36th gestational weeks. 25(OH)D and 1,25(OH)2D concentrations were measured by LC-MS/MS. Statistical analyses included longitudinal linear mixed-effects models adjusted for parity, season, education, self-reported skin color, and pre-pregnancy BMI. Vitamin D status was defined based on 25(OH)D concentrations according to the Endocrine Society Practice Guideline and Institute of Medicine (IOM) for adults. RESULTS: The prevalence of 25(OH)D <75 nmol/L was 70.4, 41.0, and 33.9%; the prevalence of 25(OH)D <50 nmol/L was 16.1, 11.2, and 10.2%; and the prevalence of 25(OH)D <30 nmol/L was 2, 0, and 0.6%, at the first, second, and third trimesters, respectively. Unadjusted analysis showed an increase in 25(OH)D (ß = 0.869; 95% CI 0.723-1.014; P < 0.001) and 1,25(OH)2D (ß = 3.878; 95% CI 3.136-4.620; P < 0.001) throughout pregnancy. Multiple adjusted analyses showed that women who started the study in winter (P < 0.001), spring (P < 0.001), or autumn (P = 0.028) presented a longitudinal increase in 25(OH)D concentrations, while women that started during summer did not. Increase of 1,25(OH)2D concentrations over time in women with insufficient vitamin D (50-75 nmol/L) at baseline was higher compared to women with sufficient vitamin D (≥75 nmol/L) (P = 0.006). CONCLUSIONS: The prevalence of vitamin D inadequacy varied significantly according to the adopted criteria. There was a seasonal variation of 25(OH)D during pregnancy. The women with insufficient vitamin D status present greater longitudinal increases in the concentrations of 1,25(OH)2D in comparison to women with sufficiency.

Dietary patterns are associated with blood lipids at 18-year-olds: a cross-sectional analysis nested in the 1993 Pelotas (Brazil) birth cohort.

BACKGROUND: Evidence regarding the deleterious effects of diet on blood lipids in adolescence has been inconsistent, and few studies have investigated this association using a dietary pattern approach. We examined whether dietary pattern of adolescents are associated with blood lipid concentrations. METHODS: Cross-sectional analysis of 3524 18-year-old participants in the 1993 Pelotas (Brazil) Birth Cohort Study. A semi-quantitative food frequency questionnaire was administered. Dietary patterns were established using principal component analysis and analysed as tertiles of factor scores. Independent associations between each dietary pattern tertile and blood lipid values (total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides) were tested using adjusted linear regression models stratified by sex. Triglycerides were log-transformed due to their skewed distribution, and the beta coefficients should be interpreted as the % change (increase or decrease). RESULTS: Four dietary patterns were derived: Meat Products and Fast Foods; Fruits and Vegetables; Candies, Sodas and Dairy Products; and Common Brazilian Foods. In the adjusted models, which compared the highest and lowest tertiles of dietary pattern scores, we observed that among girls: 1) the third tertile of the Meat Products and Fast Foods pattern was associated with 1.5 mg/dL (95% CI -3.05; -0.04) lower HDL-cholesterol; 2) the second and third tertile of the Candies, Sodas and Dairy Products pattern was associated with 5% and 10% higher triglycerides (ß 1.05, 95% CI 1.01; 1.09, ß 1.10, 95% CI 1.05; 1.16), respectively; 3) the second and third tertiles of the Common Brazilian Foods pattern were associated with 4 mg/dL (ß - 4.30, 95% CI -7.75; -0.85, ß - 4.95, 95% CI -8.53; -1.36, respectively) lower total cholesterol and 6% lower triglycerides (ß 0.94, 95% CI 0.90; 0.99, ß 0.93, 95% CI 0.89; 0.98, respectively). For boys, 4) the third tertile of the Common Brazilian Foods was associated with 4.6 mg/dL (95% CI -7.91; -1.37) lower total cholesterol and 3.8 mg/dL (95% CI -6.51; - 1.13) lower LDL-cholesterol. CONCLUSIONS: Dietary patterns were more closely associated with blood lipids among girls than boys at age 18. Higher scores for the Common Brazilian Foods pattern were associated with lower total cholesterol in both sexes.