High-dimensional analysis of 16 SARS-CoV-2 vaccine combinations reveals lymphocyte signatures correlating with immunogenicity.

The range of vaccines developed against severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) provides a unique opportunity to study immunization across different platforms. In a single-center cohort, we analyzed the humoral and cellular immune compartments following five coronavirus disease 2019 (COVID-19) vaccines spanning three technologies (adenoviral, mRNA and inactivated virus) administered in 16 combinations. For adenoviral and inactivated-virus vaccines, heterologous combinations were generally more immunogenic compared to homologous regimens. The mRNA vaccine as the second dose resulted in the strongest antibody response and induced the highest frequency of spike-binding memory B cells irrespective of the priming vaccine. Priming with the inactivated-virus vaccine increased the SARS-CoV-2-specific T cell response, whereas boosting did not. Distinct immune signatures were elicited by the different vaccine combinations, demonstrating that the immune response is shaped by the type of vaccines applied and the order in which they are delivered. These data provide a framework for improving future vaccine strategies against pathogens and cancer.

Improved biodistribution and enhanced immune response of subunit vaccine using a nanostructure formed by self-assembly of ascorbyl palmitate.

New adjuvant strategies are needed to improve protein-based subunit vaccine immunogenicity. We examined the potential to use nanostructure of 6-O-ascorbyl palmitate to formulate ovalbumin (OVA) protein and an oligodeoxynucleotide (CpG-ODN) (OCC). In mice immunized with a single dose, OCC elicited an OVA-specific immune response superior to OVA/CpG-ODN solution (OC). Rheological studies demonstrated OCC's self-assembling viscoelastic properties. Biodistribution studies indicated that OCC prolonged OVA and CpG-ODN retention at injection site and lymph nodes, reducing systemic spread. Flow-cytometry assays demonstrated that OCC promoted OVA and CpG-ODN co-uptake by Ly6ChiCD11bhiCD11c+ monocytes. OCC and OC induced early IFN-γ in lymph nodes, but OCC led to higher concentration. Conversely, mice immunized with OC showed higher serum IFN-γ concentration compared to those immunized with OCC. In mice immunized with OCC, NK1.1+ cells were the IFN-γ major producers, and IFN-γ was essential for OVA-specific IgG2c switching. These findings illustrate how this nanostructure improves vaccine's response.

Salivary Biomarkers for Oral Cancer Detection: An Exploratory Systematic Review.

Different efforts have been made to find better and less invasive methods for the diagnosis and prediction of oral cancer, such as the study of saliva as a source of biomarkers. The aim of this study was to perform a scoping review about salivary molecules that have been assessed as possible biomarkers for the diagnosis of oral squamous cell carcinoma (OSCC). A search was conducted using EBSCO, PubMed (MEDLINE), Scopus, and Web of Science. The research question was as follows: which molecules present in saliva have utility to be used as biomarkers for the early detection of oral cancer? Sixty-two studies were included. Over 100 molecules were assessed. Most of the markers were oriented towards the early diagnosis of OSCC and were classified based on their ability for detecting OSCC and oral potentially malignant disorders (OPMDs), OSCC outcome prediction, and the prediction of the malignant transformation of OPMDs. TNF-α, IL-1ß, IL-6 IL-8, LDH, and MMP-9 were the most studied, with almost all studies reporting high sensitivity and specificity values. TNF-α, IL-1ß, IL-6 IL-8, LDH, and MMP-9 are the most promising salivary biomarkers. However, more studies with larger cohorts are needed before translating the use of these biomarkers to clinical settings.

Increased Serum Total and Free 25-Hydroxyvitamin D with Daily Intake of Cholecalciferol-Fortified Skim Milk: A Randomized Controlled Trial in Colombian Adolescents.

BACKGROUND: The efficacy of cholecalciferol (vitamin D3) food fortification in low- and middle-income countries near the Equator is unknown. OBJECTIVES: We examined the effects of providing cholecalciferol-fortified skim milk to adolescents and their mothers on serum total 25(OH)D, free 25(OH)D, and vitamin D-binding protein (DBP) concentrations in a randomized controlled trial. METHODS: We randomly assigned 80 Colombian families each with a child aged 12-14.5 y and their mother 1 L of skim milk daily, either fortified with 2400 IU (60 µg) cholecalciferol or unfortified, for 6 wk. We prescribed 500 mL of milk daily to adolescents; mothers consumed the remainder ad libitum. We estimated intent-to-treat effects as the between-arm difference in the change in serum total and free 25(OH)D and DBP concentrations from baseline to the end of follow-up. Secondary analyses included stratification by baseline characteristics and per-protocol comparisons. RESULTS: Among adolescents, fortification effects (95% CI) on serum total 25(OH)D, free 25(OH)D, and DBP concentrations were 5.4 nmol/L (2.1, 8.8 nmol/L), 0.6 pmol/L (-0.2, 1.4 pmol/L), and -416 nmol/L (-944, 112 nmol/L), respectively. Effects on total 25(OH)D were stronger in adolescents with lower DBP concentrations, darker skin, less sunlight exposure, and higher compliance than in their respective counterparts. Fortification increased free 25(OH)D concentrations in high compliers. Among mothers, the effects (95% CI) on total 25(OH)D and DBP concentrations were 4.0 nmol/L (0.6, 7.5 nmol/L) and -128 nmol/L (-637, 381 nmol/L), respectively. There were no adverse events. CONCLUSIONS: Provision of cholecalciferol-fortified skim milk increases serum total 25(OH)D concentrations in Colombian adolescents and adult women.

Associations of the digit ratio with adolescent behavior problems are inconsistent with an intrauterine androgenic origin.

A low second-to-fourth digit ratio (2D:4D) is a purported biomarker of increased intrauterine androgenic exposure, presumably linked to postnatal behavior. We aimed to examine the associations between 2D:4D and adolescence behavior problems expected from high (externalizing and attention problems) or low (internalizing problems) prenatal androgen exposure. We conducted a cross-sectional study of 1042 Colombian schoolchildren aged 11-18 y. We examined whether caliper-assessed 2D:4D was associated with behavior problems per the Youth Self-Report questionnaire. Mean problem standardized score point differences were estimated between hand- and sex-specific quintiles of 2D:4D with use of multivariable linear regression. Lower right-hand 2D:4D was associated with decreased externalizing and internalizing behavior problem scores. Corresponding lowest-to-median quintile adjusted mean differences (95% CI) were -4.6 (-7.5, -1.7) and -3.5 (-6.4, -0.6) points in boys; and -3.4 (-5.9, -0.9) and -3.5 (-6.2, -0.8) points in girls. Lower right-hand 2D:4D was also related to less attention and thought problems in boys, and to less social problems among girls. Associations were nonlinear, apparent only below 2D:4D medians, and stronger with the right than the left hand. In conclusion, right-hand 2D:4D is related to behavior problems in adolescence in directions that are not fully consistent with an androgenic exposure origin.

Common infectious morbidity and white blood cell count in middle childhood predict behavior problems in adolescence.

We examined the associations of middle childhood infectious morbidity and inflammatory biomarkers with adolescent internalizing and externalizing behavior problems. We recruited 1018 Colombian schoolchildren aged 5-12 years into a cohort. We quantified white blood cell (WBC) counts and C-reactive protein at enrollment and prospectively recorded incidence of gastrointestinal, respiratory, and fever-associated morbidity during the first follow-up year. After a median 6 years, we assessed adolescent internalizing and externalizing behavior problems using child behavior checklist (CBCL) and youth self-report (YSR) questionnaires. Behavior problem scores were compared over biomarker and morbidity categories using mean differences and 95% confidence intervals (CI) from multivariable linear regression. Compared with children without symptoms, CBCL internalizing problem scores were an adjusted 2.5 (95% CI: 0.1, 4.9; p = .04) and 3.1 (95% CI: 1.1, 5.2; p = .003) units higher among children with moderate diarrhea with vomiting and high cough with fever rates, respectively. High cough with fever and high fever rates were associated with increased CBCL somatic complaints and anxious/depressed scores, respectively. WBC >10,000/mm3 was associated with both internalizing problem and YSR withdrawn/depressed scores. There were no associations with externalizing behavior problems. Whether or not decreasing the burden of common infections results in improved neurobehavioral outcomes warrants further investigation.

Leukocyte telomere length predicts subsequent infectious morbidity among Colombian schoolchildren.

OBJECTIVE: Telomere length (TL) attrition is related to chronic disease risk. However, less is known on whether TL predicts infectious outcomes, especially in childhood. We examined whether leukocyte TL (LTL) was associated with subsequent infectious morbidity in schoolchildren. METHODS: We assessed LTL in 717 Colombian children 5-12 years-old at the beginning of a school year and followed them through the year for daily occurrence of common infection symptoms and doctor visits. We estimated adjusted incidence rate ratios (IRR) with 95% confidence intervals (CI) of gastrointestinal and respiratory syndromes for quartiles of standardized LTL Z score and per unit LTL Z score. RESULTS: A longer LTL was associated with increased incidence of all infectious morbidity syndromes considered. Adjusted IRR (95% CI) per unit LTL Z score were 1.55 (1.20, 2.00) for diarrhea with vomiting, 1.34 (1.13, 1.60) for cough with fever, 1.70 (1.28, 2.28) for ear infection, and 1.66 (1.36, 2.02) for doctor visits with symptoms. CONCLUSIONS: Longer LTL is related to increased incidence of common infectious morbidities in middle childhood.

Sleep duration in middle childhood and age at menarche.

OBJECTIVE: Puberty affects sleep phasing. However, it is unclear if sleep duration earlier in childhood could influence the timing of pubertal events. We aimed to assess the association between middle childhood nighttime sleep duration and age at menarche (AAM). METHODS: In a cohort of 819 premenarcheal Colombian girls who were followed annually for the occurrence of menarche, we estimated adjusted hazard ratios (HR) with 95% confidence intervals (CI) for menarche by categories of recommended sleep duration in middle childhood using Cox models. Analyses were stratified by age at sleep assessment. RESULTS: Among girls aged 9 to <11 years, compared with girls who slept within recommendations, sleeping above recommendations was related to an adjusted 76% (95% CI: 4%, 198%; p = .04) higher probability of experiencing menarche during follow up. In girls aged ≥11 years, compared with girls who slept within recommendations, sleeping under recommendations was related to an adjusted 42% (95% CI: 5%, 93%; p = .03) higher probability of experiencing menarche during follow-up. Sleep duration was not associated with AAM in girls aged <9 years at the time of sleep assessment. CONCLUSIONS: Sleeping above recommendations in girls 9 to <11 years-old and sleeping under recommendations in girls ≥11 years-old is associated with earlier menarche.

Middle childhood and adolescence sleep duration and behavior problems in adolescence.

We examined the associations of middle childhood and adolescence nighttime sleep duration with adolescence internalizing and externalizing behavior problems per the Youth Self-Report (YSR) and the Child Behavior Checklist (CBCL) questionnaires, in a cohort of 889 Colombian schoolchildren. We estimated adjusted differences with 95% confidence intervals (CI) in mean behavior problem t-scores in standardized units between recommended sleep duration categories and as a continuous exposure using multiple linear regression and restricted cubic spline models, respectively. Compared with sleep duration within recommendations, middle childhood sleep above recommendations was related to 4.6 (95% CI: 1.6, 7.6; p = .004) and 5.4 (95% CI: 1.2, 9.7; p = .01) adjusted units higher YSR and CBCL externalizing problem scores, respectively. In continuous exposure analyses, this association seemed restricted to children aged ≥11 years. Longer sleep, both in categories and as a continuous exposure, was also associated with increased CBCL internalizing problems. Results did not differ by sex or weekend/weekday sleep. Sleeping under recommendations in middle childhood was not significantly related to behavior problems; nevertheless, shorter sleep in adolescence, in both categorical and continuous scales, was significantly related to behavior problems. In conclusion, behavior problems in adolescence are associated with longer sleep in middle childhood and shorter sleep in adolescence.

Vitamin D Deficiency in Middle Childhood Is Related to Behavior Problems in Adolescence.

BACKGROUND: Vitamin D deficiency (VDD) is associated with depression and schizophrenia in adults. The effect of VDD in childhood on behavioral development is unknown. OBJECTIVES: We aimed to study the associations of VDD and vitamin D binding protein (DBP) in middle childhood with behavior problems in adolescence. METHODS: We quantified plasma total 25-hydroxyvitamin D [25(OH)D] and DBP in 273 schoolchildren aged 5-12 y at recruitment into a cohort study in Bogota, Colombia. Externalizing and internalizing behavior problems were assessed after a median 6-y follow-up by parental report [Child Behavior Checklist (CBCL)] and self-report [Youth Self-Report (YSR)]. We estimated mean problem score differences with 95% CIs between exposure categories using multivariable linear regression. We also compared the prevalence of clinical behavior problems (score >63) between exposure groups. We assessed whether the associations between DBP and behavior problems were mediated through VDD. RESULTS: Mean ± SD CBCL and YSR externalizing problems scores were 56.5 ± 9.3 and 53.2 ± 9.5, respectively. Internalizing problems scores averaged 57.1 ± 9.8 and 53.7 ± 9.8, respectively. VDD [25(OH)D <50 nmol/L] prevalence was 10.3%. VDD was associated with an adjusted 6.0 (95% CI: 3.0, 9.0) and 3.4 (95% CI: 0.1, 6.6) units higher CBCL and YSR externalizing problems scores, respectively, and an adjusted 3.6 (95% CI: 0.3, 6.9) units higher CBCL internalizing problems scores. The prevalence of clinical total externalizing problems was 1.8 (95% CI: 1.1, 3.1) times higher in children with VDD than that in children without VDD. DBP concentration below the population median was related to higher YSR aggressive behavior and anxious/depressed subscale scores and to higher prevalence of clinical total externalizing problems. The associations between DBP and behavior problems were not mediated through VDD. CONCLUSIONS: VDD and low DBP in middle childhood are related to behavior problems in adolescence.

Micronutrient status and leukocyte telomere length in school-age Colombian children.

PURPOSE: Leukocyte telomere length (LTL) is a biomarker of inflammation and oxidative stress that predicts chronic disease risk. Nutritional factors are related to LTL in adulthood, but these associations are not well characterized in children. We examined whether micronutrient status biomarkers were associated with LTL in school-age children. METHODS: We conducted a cross-sectional study of 330 boys and 393 girls aged 5-12 years from Bogotá, Colombia. We quantified blood concentrations of hemoglobin, ferritin, zinc, vitamin A, folate, and vitamin B-12; and measured LTL using qPCR in DNA extracted from buffy coat. We estimated mean differences in LTL by quartiles of micronutrient status biomarkers and categories of relevant sociodemographic and anthropometric covariates with the use of linear regression. RESULTS: In girls, plasma vitamin B-12 was positively associated with LTL (adjusted LTL difference between extreme vitamin B-12 quartiles = 0.11; P, trend = 0.02). LTL was also positively associated with birth order in girls (P, trend = 0.02). In boys, LTL was not related to the micronutrient status biomarkers but, unexpectedly, it was positively associated with birth weight (P = 0.02), height-for-age Z score (P, trend = 0.01), and serum C-reactive protein (P, trend = 0.01). CONCLUSIONS: LTL is associated with vitamin B-12 status among girls. LTL is also associated with birth weight, height, and C-reactive protein in boys.

Iron Deficiency, Anemia, and Low Vitamin B-12 Serostatus in Middle Childhood Are Associated with Behavior Problems in Adolescent Boys: Results from the Bogotá School Children Cohort.

BACKGROUND: Iron deficiency (ID) in infancy is related to subsequent behavior problems. The effects of micronutrient status in middle childhood are uncertain. OBJECTIVE: The aim of the study was to examine the associations of micronutrient status biomarkers in middle childhood with externalizing and internalizing behavior problems in adolescence. METHODS: We assessed whether ID (ferritin <15 µg/L), anemia (hemoglobin <12.7 g/dL), or blood concentrations of zinc, vitamins A and B-12, and folate at ages 5-12 y were associated with externalizing or internalizing behavior problems in adolescence in 1042 schoolchildren from Bogotá, Colombia. Behavior problems were assessed with the Youth Self-Report questionnaire after a median 6.2 y of follow-up. Mean problem score differences with 95% CIs were estimated between categories of micronutrient status biomarkers with the use of multivariable linear regression. RESULTS: Mean ± SD externalizing and internalizing problems scores were 52.6 ± 9.6 and 53.8 ± 9.9, respectively. Among boys, middle-childhood ID, anemia, and low plasma vitamin B-12 were associated with 5.9 (95% CI: 1.0, 10.7), 6.6 (95% CI: 1.9, 11.3), and 2.7 (95% CI: 0.4, 4.9) units higher mean externalizing problems scores in adolescence, respectively-after adjustment for baseline age, time spent watching television or playing video games, mother's height, and socioeconomic status. Also in boys, ID was related to an adjusted 6.4 (95% CI: 1.2, 11.6) units higher mean internalizing problems score. There were no associations among girls. Other micronutrient status biomarkers were not associated with behavior problems. CONCLUSIONS: ID, anemia, and low vitamin B-12 in middle childhood are related to behavior problems in adolescent boys.This study was registered at clinicaltrials.gov as NCT03297970.

Processed and ultra-processed foods are associated with lower-quality nutrient profiles in children from Colombia.

OBJECTIVE: To determine if processed and ultra-processed foods consumed by children in Colombia are associated with lower-quality nutrition profiles than less processed foods. DESIGN: We obtained information on sociodemographic and anthropometric variables and dietary information through dietary records and 24 h recalls from a convenience sample of the Bogotá School Children Cohort. Foods were classified into three categories: (i) unprocessed and minimally processed foods, (ii) processed culinary ingredients and (iii) processed and ultra-processed foods. We also examined the combination of unprocessed foods and processed culinary ingredients. SETTING: Representative sample of children from low- to middle-income families in Bogotá, Colombia. SUBJECTS: Children aged 5-12 years in 2011 Bogotá School Children Cohort. RESULTS: We found that processed and ultra-processed foods are of lower dietary quality in general. Nutrients that were lower in processed and ultra-processed foods following adjustment for total energy intake included: n-3 PUFA, vitamins A, B12, C and E, Ca and Zn. Nutrients that were higher in energy-adjusted processed and ultra-processed foods compared with unprocessed foods included: Na, sugar and trans-fatty acids, although we also found that some healthy nutrients, including folate and Fe, were higher in processed and ultra-processed foods compared with unprocessed and minimally processed foods. CONCLUSIONS: Processed and ultra-processed foods generally have unhealthy nutrition profiles. Our findings suggest the categorization of foods based on processing characteristics is promising for understanding the influence of food processing on children's dietary quality. More studies accounting for the type and degree of food processing are needed.

Micronutrient status in middle childhood and age at menarche: results from the Bogotá School Children Cohort.

Childhood intake of animal foods is associated with age at first menstrual period (menarche). It is unknown whether the micronutrients present in these foods could explain this association. Our objective was to investigate the associations of micronutrient status biomarkers in middle childhood with age at menarche. We quantified circulating Hb, ferritin, mean corpuscular volume, Zn, vitamin B12, erythrocyte folate and retinol in 1464 pre-menarcheal girls aged 5-12 years in Bogotá, Colombia, and followed them for a median 5·7 years for the occurrence and date of menarche. We estimated median age at menarche and hazard ratios (HR) with 95 % CI by levels of each biomarker with use of Kaplan-Meier survival probabilities and Cox regression, respectively. Median age at menarche was 12·4 years. Middle childhood Hb was inversely related to age at menarche whereas plasma ferritin was positively associated with this outcome in a linear manner. HR of menarche for every 1 sd of Hb (11 g/l) and ferritin (23·2 µg/l) were 1·11 (95 % CI 1·04, 1·18; P=0·001) and 0·94 (95 % CI 0·88, 0·99; P=0·02), respectively, after adjustment for baseline age, C-reactive protein concentration, maternal age at menarche and parity and socioeconomic status. The association with ferritin was stronger in girls aged 9-10 years at baseline. Additional adjustment for baseline height- and BMI-for-age did not change the results. We conclude that higher Fe status in middle childhood is related to later age at menarche whereas Hb concentrations are inversely associated with age at onset of menses.

Maternal body image dissatisfaction and BMI change in school-age children.

OBJECTIVE: Parental body image dissatisfaction (BID) is associated with children's weight in cross-sectional studies; however, it is unknown whether BID predicts development of adiposity. The objective of the present study was to investigate the associations between maternal dissatisfaction with her or her child's body and children's BMI trajectories. DESIGN: Longitudinal study. Maternal dissatisfaction (BID) with her and her child's body was calculated based on ratings of Stunkard scales obtained at recruitment, as current minus desired body image. Children's height and weight were measured at baseline and annually for a median of 2·5 years. Mixed-effects models with restricted cubic splines were used to construct sex- and weight-specific BMI-for-age curves according to maternal BID levels. SETTING: Public primary schools in Bogotá, Colombia. SUBJECTS: Children (n 1523) aged 5-12 years and their mothers. RESULTS: After multivariable adjustment, heavy boys and thin girls whose mothers desired a thinner child gained an estimated 1·7 kg/m2 more BMI (P=0·04) and 2·4 kg/m2 less BMI (P=0·004), respectively, between the age 6 and 14 years, than children of mothers without BID. Normal-weight boys whose mothers desired a thinner child's body gained an estimated 1·8 kg/m2 less BMI than normal-weight boys of mothers without BID (P=0·02). Maternal BID with herself was positively related to children's BMI gain during follow-up. CONCLUSIONS: Maternal BID is associated with child's BMI trajectories in a sex- and weight-specific manner.

Higher Childhood Red Meat Intake Frequency Is Associated with Earlier Age at Menarche.

BACKGROUND: Early age at menarche is associated with increased breast cancer risk. Red meat consumption in adolescence predicts breast cancer risk, but it is unknown whether it is also related to earlier menarche. OBJECTIVE: We studied the association between intake of red meat at ages 5-12 y and age at menarche in a prospective study. METHODS: We assessed usual diets with a food-frequency questionnaire in a group of 456 girls aged 8.4 ± 1.7 y and followed them for a median 5.6 y in Bogotá, Colombia. Girls were asked periodically about the occurrence and date of menarche. Median age at menarche was estimated with use of Kaplan-Meier survival probabilities by categories of red meat intake frequency. Cox proportional hazards models were used to compare the incidence of menarche by red meat intake frequency, adjusting for potential sociodemographic and dietary confounders including total energy intake and intake frequency of other animal food groups (dairy, poultry, freshwater fish, tuna/sardines, eggs, and innards). RESULTS: Median age at menarche was 12.4 y. After adjustment for total energy intake, maternal parity, and socioeconomic status, red meat intake frequency was inversely associated with age at menarche. When compared with girls with red meat intake <4 times/wk, those consuming it ≥2 times/d had a significantly earlier age at menarche (HR: 1.64; 95% CI: 1.11, 2.41; P-trend = 0.0009). Incidentally, we found that girls with tuna/sardine intake >1 time/wk had a significantly later age at menarche (HR: 0.62; 95% CI: 0.42, 0.90; P = 0.01) than those with intake <1 time/mo. Intake frequency of other animal food groups was not significantly associated with age at menarche. CONCLUSION: Higher red meat intake frequency during childhood is associated with an earlier age at menarche, whereas greater fatty fish intake frequency is associated with a later menarcheal age.

Vitamin B-12 Deficiency in Children Is Associated with Grade Repetition and School Absenteeism, Independent of Folate, Iron, Zinc, or Vitamin A Status Biomarkers.

BACKGROUND: Micronutrients are essential to neurocognitive development; yet their role in educational outcomes is unclear. OBJECTIVE: We examined the associations of micronutrient status biomarkers with the risk of grade repetition and rates of school absenteeism in a cohort of school children. METHODS: We recruited 3156 children aged 5-12 y from public schools in Bogota, Colombia. Circulating ferritin, hemoglobin, zinc, vitamin A, and vitamin B-12; erythrocyte folate; and mean corpuscular volume (MCV) were measured in blood samples obtained at the beginning of the year. Absenteeism was recorded weekly during the school year, and grade repetition was determined the next year. Risk ratios for grade repetition and rate ratios for absenteeism were estimated by categories of micronutrient status indicators with use of Poisson regression, adjusting for potential confounders. RESULTS: The risk of grade repetition was 4.9%, and the absenteeism rate was 3.8 d per child-year of observation. Vitamin B-12 deficiency (<148 pmol/L) was associated with an adjusted 2.36-fold greater risk of grade repetition (95% CI: 1.03, 5.41; P = 0.04) compared with plasma concentrations ≥148 pmol/L. Other micronutrients were not related to grade repetition. Vitamin B-12 deficiency was also associated with school absenteeism rates. Compared with children with plasma vitamin B-12 concentrations ≥148 pmol/L, vitamin B-12-deficient children had a 1.89-times higher adjusted rate (95% CI: 1.53, 2.34; P < 0.0001). Anemia was related to a 72% higher rate (95% CI: 48%, 99%; P < 0.0001), whereas every 5-fL difference in MCV was associated with a 7% lower adjusted rate (95% CI: 4%, 10%; P < 0.0001). CONCLUSIONS: Vitamin B-12 deficiency was associated with risk of grade repetition and school absenteeism rates in school children from Bogota, Colombia. The effects of correcting vitamin B-12 deficiency on educational outcomes and neurocognitive development of school children need to be determined in intervention studies.

Serum Trans Fatty Acids Are Not Associated with Weight Gain or Linear Growth in School-Age Children.

BACKGROUND: Animal and human adult studies indicate that long-term intake of trans fatty acids (TFAs) may be associated with weight gain. High intake of fast foods and snacks, which are rich in TFAs, is linked to overweight status among school-age children. However, the specific effects of TFAs in this population are unknown. OBJECTIVE: We examined whether serum TFAs, used as biomarkers of intake, are associated with faster weight gain and linear growth during school years. METHODS: We quantified TFAs by GLC in serum samples of 668 children aged 5-12 y at the time of recruitment into an ongoing cohort study performed in Bogota (Colombia) since 2006. Serum proportions of trans palmitoleic acid (16:1t), trans oleic acid (18:1t), trans linoleic acid (18:2t), and total TFAs were used as biomarkers of intake. Anthropometric characteristics were measured periodically for a median of 30 mo. Body mass index-for-age z scores (BAZs) and height-for-age z scores (HAZs) were calculated with the use of the WHO reference. We estimated mean changes in BAZs and HAZs over follow-up according to quartiles of each TFA at baseline by using mixed-effects regression models with restricted cubic splines. RESULTS: Proportions of trans palmitoleic acid, trans oleic acid, trans linoleic acid, and total TFAs (mean ± SD, % of total serum FAs), were 0.22 ± 0.06, 0.91 ± 0.37, 0.96 ± 0.27, and 2.10 ± 0.59, respectively. Serum TFAs were not associated with changes in BAZs and HAZs after adjusting for sex, baseline age, and socioeconomic status. In a subgroup analysis by sex, serum trans palmitoleic acid was positively associated with the estimated change in HAZs from ages 6 to 14 y in boys (with use of the first quartile as the reference, differences in HAZs for trans palmitoleic acid quartiles were 0.73, 0.53, and 0.70, P-trend = 0.03). CONCLUSIONS: Proportions of serum TFAs, used as biomarkers of TFA intake, were not associated with weight gain in children aged 6-14 y in low- and middle-income populations in Bogota. The proportion of trans palmitoleic acid was positively associated with linear growth in boys. Longer follow-up and studies in diverse cohorts with wider ranges of TFA intake are warranted.

Trans-fatty acids in cooking oils in Bogota, Colombia: changes in the food supply from 2008 to 2013.

OBJECTIVE: Long-chain n-3 fatty acid intake in Colombia is low because fish consumption is limited. Vegetable oils with high n-3 fatty acid content are recommended, but their concentrations of trans fats were high in previous studies. Thus, regular monitoring of the fatty acid composition of vegetable oils is required. Our objective was to quantify the fatty acid composition in commercially available oils in Bogota, Colombia and determine if composition changed from 2008 to 2013. DESIGN: Cross-sectional study. We obtained samples of all commercially available oils reported in a survey of low- and middle-income families with a child participating in the Bogota School Children Cohort. SETTING: Bogota, Colombia. SUBJECTS: Not applicable. RESULTS: Sunflower oil had the highest trans-fatty acid content (2.18%). Canola oil had the lowest proportion of trans-fatty acids (0.40%) and the highest n-3 fatty acid content (9.37%). In terms of percentage reduction from 2008 to 2013 in 18:1 and 18:2 trans-fatty acids, canola oil had 89% and 65% reduction, mixed oils had 44% and 48% reduction, and sunflower oil had 25% and 51 % reduction, respectively. Soyabean oil became widely available in 2013. CONCLUSIONS: The content of trans-fatty acids decreased in all oils from 2008 to 2013, suggesting a voluntary reduction by industry. We believe that regular monitoring of the fatty acid composition of oils is warranted.

A prospective study of body image dissatisfaction and BMI change in school-age children.

OBJECTIVE: Body image dissatisfaction (BID) in school-age children is positively associated with weight status in cross-sectional studies; however, it is uncertain whether BID is a risk factor for the development of adiposity over time. The aim of the present study was to examine the association of BID with changes in BMI in school-age children. DESIGN: Longitudinal study. At recruitment, children were asked to indicate the silhouette that most closely represented their current and desired body shapes using child-adapted Stunkard scales. Baseline BID was calculated as the difference of current minus desired body image. Height and weight were measured at recruitment and then annually for a median of 2·5 years. Sex-specific BMI-for-age curves were estimated by levels of baseline BID, using mixed-effects models with restricted cubic splines. SETTING: Public primary schools in Bogotá, Colombia. SUBJECTS: Six hundred and twenty-nine children aged 5-12 years. RESULTS: In multivariable analyses, thin boys who desired to be thinner gained an estimated 5·8 kg/m2 more BMI from age 6 to 14 years than boys without BID (P = 0·0004). Heavy boys who desired to be heavier or thinner gained significantly more BMI than boys without BID (P = 0·003 and P = 0·007, respectively). Thin girls who desired to be heavier or thinner gained significantly less BMI than girls without BID (P = 0·0008 and P = 0·05, respectively), whereas heavy girls who desired to be heavier gained an estimated 4·8 kg/m2 less BMI than girls without BID (P = 0·0006). BID was not related to BMI change in normal-weight children. CONCLUSIONS: BID is associated with BMI trajectories of school-age children in a sex- and weight-specific manner.