BMI In Infancy Research Articles

Childhood Obesity and the Risk of Hypertension in the Caribbean Region: A Narrative Review

Childhood obesity is a rising epidemic affecting both developed and developing countries worldwide. In the Caribbean, estimates of obesity in children are noted to be above the predicted global values, and evidence suggests that the rise in obesity levels is due to environmental influences in dietary practices and physical inactivity. Methods: This review aims to determine the effects of childhood obesity and the associated risks of developing hypertension in the Caribbean population. Research articles were identified using computer-based search engines such as Google Scholar, PubMed, ScienceDirect, World Health Organization (WHO), and Caribbean Public Health Agency (CARPHA) databases. Researched articles with various study designs were then thoroughly analyzed to extract detailed information about obesity in childhood and the risks for hypertension in later years. Results: Rapid weight gain in infancy and high (body mass index) BMI levels in childhood are associated with higher blood pressure values and increased cardiovascular risk. Additionally, direct baseline elevation of blood pressure (B.P.) measurements, noted in obese/overweight children compared to their nonobese counterparts, confirm the hypothesis that childhood obesity is positively associated with hypertension. Conclusion: This review article provides detailed facts about childhood obesity, the risk for hypertension, and improvement recommendations and calls attention to the health implications of obesity-related hypertension in children if left untreated.

Maternal pre-pregnancy weight and early life lower respiratory tract infections in a low-income urban minority birth cohort

The prevalence of maternal obesity has increased dramatically with adverse consequences on infant health. Prior studies have reported associations between maternal obesity and childhood wheeze, asthma as well as lower respiratory tract infections (LRTI). However, studies examining the association of obesity with early-life LRTIs in low-income urban minority populations are still lacking. This is a critical gap because both obesity and infant respiratory morbidity are more prevalent and severe in these communities. We examined mother‐child dyads from the Boston Birth Cohort (BBC) to define the longitudinal association of maternal pre‐pregnancy BMI and LRTI in infancy, defined as the presence of bronchiolitis, bronchitis, or pneumonia during the first year of life (< 12 months of age). A total of 2,790 mother‐child dyads were included in our analyses. Infants born to pre-pregnancy obese mothers (n = 688, 25%) had 1.43 increased odds (adjOR = 1.43, 95% CI 1.08–1.88, p = 0.012) of developing LRTI during the first year of life when compared with newborns born to normal-weight mothers after adjusting by relevant LRTI risk factors. Notably, infants born to overweight mothers (n = 808, 29%) followed a similar trend (adjOR = 1.31, 95% CI 1.00–1.72, p = 0.048). Our study demonstrated that maternal pre-pregnancy obesity is an independent risk factor for the development of LRTI during infancy in a low-income urban minority birth cohort.

Gestational perfluoroalkyl substance exposure and body mass index trajectories over the first 12 years of life.

Background/Objectives:Gestational exposure to perfluoroalkyl substances (PFAS), a ubiquitous class of persistent endocrine disrupting chemicals, is associated with increased risk of obesity and cardiometabolic disease. However, it is unclear if gestational PFAS exposure is associated with adiposity trajectories related to adult obesity and cardiometabolic health.Subjects/Methods:We measured perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononaoic acid, and perfluorohexanesulfonic acid (PFHxS) concentrations in maternal serum collected between 16-weeks gestation and delivery in a cohort of 345 mother-child pairs in Cincinnati, OH (enrolled 2003–06). From age 4-weeks to 12 years, we measured weight and length or height up to eight times and calculated child BMI (1,865 repeated measures). Using covariate-adjusted linear mixed models and splines to account for repeated BMI measures and non-linear BMI patterns, respectively, we estimated the age/magnitude of infancy BMI zenith (~1 year) and childhood BMI nadir (~5 years), BMI accrual from 8–12 years, and BMI at age 12 years by PFAS terciles.Results:BMI trajectories varied by PFOA concentrations (age × PFOA interaction p-value=0.03). Children born to women with higher PFOA concentrations had lower infancy and early childhood BMI, earlier BMI nadir, accelerating BMI gains in mid-childhood and adolescence, and higher BMI at age 12 years. Some of these associations were non-monotonic. PFOS and PFHxS were not associated with alterations in BMI trajectories, but were monotonically associated with lower BMI across infancy, childhood, and adolescence. Compared to children in the 1st PFOS tercile, those in the 2nd (β:-0.83; 95%CI:-2.11, 0.51 kg/m2) and 3rd (β:-1.41; 95%CI:-2.65, -0.14 kg/m2) had lower BMI at age 12 years.Conclusions:These results suggest that gestational PFOA exposure may be associated with BMI trajectories related to adult obesity and cardiometabolic disease, while PFOS and PFHxS exposure is associated with lower BMI in the first 12 years of life.

Maternal gestational diabetes and infant feeding, nutrition and growth: a systematic review and meta-analysis.

Gestational diabetes mellitus (GDM) is a major health problem, with increased risks of obesity and diabetes in offspring. However, little is known about the effect of GDM on infant feeding, nutrition and growth, and whether these factors play a role in mediating these risks. We systematically reviewed evidence for the effect of GDM on infant feeding, nutrition and growth. We searched MEDLINE, Web-of-Science, Embase, CINAHL and CENTRAL for studies that reported outcomes in infants <2 years who were and were not exposed to GDM. Studies of pre-gestational diabetes were excluded. Meta-analysis was performed for three epochs (1–6, 7–12, 13–24 months), using inverse-variance, fixed-effects methods. Primary outcomes were energy intake (kJ) and BMI (kg/m2). Twenty-five studies and 308 455 infants were included. Infants exposed to GDM, compared with those not exposed, had similar BMI at age 1–6 months (standardised mean difference (SMD) = 0·01, 95 % CI −0·04, 0·06; P = 0·69) and 7–12 months (SMD = 0·04, 95 % CI −0·01, 0·10; P = 0·09), reduced length at 1–6 and 7–12 months, increased whole-body fat at 1–6 months, higher rates of formula supplementation in hospital, shorter duration of breast-feeding and decreased rates of continued breast-feeding at 12 months. Breast milk of women with GDM had lower protein content. There was no association between GDM and infant weight and skinfold thickness. No data were available for nutritional intake and outcomes at 13–24 months. Low- or very low-quality evidence suggests GDM is not associated with altered BMI in infancy, but is associated with increased fat mass, high rates of formula use and decreased duration of breast-feeding.

Breast Milk Supply of MicroRNA Associated with Leptin and Adiponectin Is Affected by Maternal Overweight/Obesity and Influences Infancy BMI.

Breast milk constitutes a dietary source of leptin, adiponectin and microRNAs (miRNAs) for newborns. Expression of miRNAs previously associated with maternal obesity, leptin or adiponectin function were assessed and their impact on infant weight analyzed. Milk samples were collected (at month 1, 2, and 3) from a cohort of 59 healthy lactating mothers (38 normal-weight and 21 overweight/obese (BMI ≥ 25)), and infant growth was followed up to 2 years of age. Thirteen miRNAs, leptin and adiponectin were determined in milk. Leptin, adiponectin and miRNA showed a decrease over time of lactation in normal-weight mothers that was altered in overweight/obesity. Furthermore, negative correlations were observed in normal-weight mothers between the expression of miRNAs in milk and the concentration of leptin or adiponectin, but were absent in overweight/obesity. Moreover, miRNAs negatively correlated with infant BMI only in normal-weight mothers (miR-103, miR-17, miR-181a, miR-222, miR-let7c and miR-146b). Interestingly, target genes of milk miRNAs differently regulated in overweight/obesity could be related to neurodevelopmental processes. In conclusion, a set of miRNAs present in breast milk, in close conjunction with leptin and adiponectin, are natural bioactive compounds with the potential to modulate infant growth and brain development, an interplay that is disturbed in the case of maternal overweight/obesity.

Pre-pregnancy parental BMI and offspring blood pressure in infancy.

AimsA growing body of evidence suggests that a higher maternal pre-pregnancy body mass index results in higher offspring’s blood pressure, but there is inconsistency about the impact of father’s body mass index. Furthermore, evidence is limited with regard to low and middle income countries. We aimed to determine the association between parental pre-pregnancy body mass index and offspring’s blood pressure during the first year of life.MethodsIn 587 infants of the BReastfeeding Attitude and Volume Optimization (BRAVO) trial systolic and diastolic blood pressure were measured twice at the right leg in a supine position, using an automatic oscillometric device at day 7, month 1, 2, 4, 6, 9 and 12. Parental pre-pregnancy body mass index was based on self-reported weight and height. Linear mixed models were performed to investigate the associations between parental pre-pregnancy body mass index and offspring blood pressure patterns.ResultsEach unit increase in maternal body mass index was associated with 0.24 mmHg (95% confidence interval 0.05; 0.44) and 0.13 mmHg (0.01; 0.25) higher offspring’s mean systolic and diastolic blood pressure, respectively, during the first year of life. A higher offspring blood pressure with increased maternal pre-pregnancy body mass index was seen at birth and remained higher during the first year of life. The association with systolic blood pressure remained similar after including birth size and offspring’s weight and height over time. The association with diastolic blood pressure attenuated slightly to a non-significant result after including these variables. Paternal body mass index was not associated with offspring’s blood pressure.ConclusionHigher maternal pre-pregnancy body mass index, but not paternal pre-pregnancy body mass index, is associated with higher offspring blood pressure already from birth onwards.

GWAS on longitudinal growth traits reveals different genetic factors influencing infant, child, and adult BMI.

Early childhood growth patterns are associated with adult health, yet the genetic factors and the developmental stages involved are not fully understood. Here, we combine genome-wide association studies with modeling of longitudinal growth traits to study the genetics of infant and child growth, followed by functional, pathway, genetic correlation, risk score, and colocalization analyses to determine how developmental timings, molecular pathways, and genetic determinants of these traits overlap with those of adult health. We found a robust overlap between the genetics of child and adult body mass index (BMI), with variants associated with adult BMI acting as early as 4 to 6 years old. However, we demonstrated a completely distinct genetic makeup for peak BMI during infancy, influenced by variation at the LEPR/LEPROT locus. These findings suggest that different genetic factors control infant and child BMI. In light of the obesity epidemic, these findings are important to inform the timing and targets of prevention strategies.

Associations of Infant Sleep Duration with Body Composition and Cardiovascular Health to Mid-Adolescence: The PEAS Kids Growth Study.

Background: Short sleep duration in childhood has often been linked with obesity in later childhood or adolescence. However, whether infant sleep duration affects body composition trajectories and cardiovascular health through to mid-adolescence remains unknown. Methods: Participants were 336 adolescents from a community-based prospective birth cohort in Melbourne, Australia. Mothers completed 24-hour time diaries, including infant sleep in 5-minute intervals at ages 2, 4, and 12 months. BMI and body composition outcomes were measured 6-monthly between 4 and 6.5 years and at 10 and 14 years. Cardiovascular outcomes at 14 years comprised blood pressure, pulse wave velocity, retinal arteriole-to-venule ratio, and carotid intima-media thickness. We used multivariable linear regression and multinomial logistic regression analyses adjusted for sex, age, BMI at birth, gestational age, ethnicity, maternal education, maternal BMI, and neighborhood socioeconomic position. Results: At 2 months, infants slept on average 14.1 hours [standard deviation (SD) 1.9], decreasing to 13.4 hours (SD 2.0) by 12 months. We observed no associations between the different sleep duration time points in infancy and later BMI or body composition. Moreover, a shorter sleep duration did not increase the odds of being on a high body composition trajectory compared with longer sleep (e.g., odds ratio per hour of sleep at 4 months is 0.85, 95% confidence interval 0.65-1.11). Infant sleep duration was also not associated with cardiovascular function or large or small artery structure at 14 years of age. Conclusions: We found no evidence that sleep duration very early in life affects adolescent body composition or cardiovascular health.

Effects of dietary intake patterns from 1 to 4\xa0years on BMI z-score and body shape at age of 6 years: a prospective birth cohort study from Brazil

PurposeTo assess the association between dietary intake patterns from 1 to 4 years and BMI and body shape at age of 6 years.MethodsThis longitudinal study was based on 3374 Brazilian children from the 2004 Pelotas Birth Cohort Study. We used previously described dietary patterns from 1 to 4 years as the main exposure. We defined body shape using scores for corpulence (a recently described body shape component measured by Photonic Scanner), and trunk and gynoid fat mass percentage from DXA. We run linear regression models to evaluate the associations between dietary patterns from 1 to 4 years and BMI and body shape at 6 years.ResultsSeveral apparent associations between dietary patterns and BMI or body shape were explained by sociodemographic factors. High adherence to snacks (positive loadings to coffee, bread and cookies) at 4 years predicted lower BMI, but higher gynoid fat mass percentage at 6 years, while higher adherence to staple at 2 years (positive loadings to rice and beans) predicted higher trunk fat mass and lower gynoid fat mass. Finally, higher scores on milks at 1 year (positive loading to breast milk) predicted higher gynoid fat mass at 6 years.ConclusionThere were inconsistent associations between dietary patterns in infancy and early childhood and BMI and body shape at 6 years. In adjusted analyses, higher adherence to breast milk at 1 year and to snacks at 4 years appeared to be beneficial for body shape, associated with lower BMI, but higher peripheral fat.

Patterns of early life body mass index and childhood overweight and obesity status at eight years of age

BackgroundExcess weight gain in infancy and childhood is associated with increased risk of subsequent obesity. Identifying patterns of infancy and childhood weight gain associated with subsequent obesity or overweight status could help identify children at highest risk. Thus, we examined patterns of infancy and early childhood BMI in relation to mid-childhood overweight and obesity status.MethodsIn a prospective cohort of 215 children from Cincinnati, OH (born: 2003–2006), we measured weight and length or height at ages 4 weeks and 1, 2, 3, 4, 5, and 8 years. We calculated BMI z-scores using World Health Organization references. Using linear fixed effect models, we estimated mean BMI at each age and rates of change in BMI between ages 4 weeks and 5 years by children’s overweight and obesity status at age 8 years, assessed with BMI z-scores or bioelectric impedance analysis (BIA).ResultsChildren who became overweight (BMI, n = 51 and BIA, n = 37) or obese (BMI, n = 22 and BIA, n = 29) at age 8 years had greater BMI at all ages compared to normal weightchildren. Children who were overweight had similar rates of change in BMI as children who were lean. Children who were obese had greater gains in BMI between age 4 weeks and 5 years, with the most rapid gains in the first 2 years.ConclusionsResults from this study of modest sample size, suggest that adiposity patterns in the first 5 years of life are related to subsequent childhood overweight and obesity risk.

Which family-centered educational interventions are effective for preventing childhood obesity?

EVIDENCE-BASED ANSWER Parental education on appropriate introduction of healthy solid feeding practices, recognizing infant hunger and satiety cues, and encouraging active play leads to lower BMI-for-age Z-score (BMIZ), weight-forlength percentile measures, and overall BMI in infancy (SOR: B, 1 RCT using each outcome). Effect on weight beyond 1 and 2 years old and effect on other health measures are unknown.

Breastfeeding in Infancy Is Associated with Body Mass Index in Adolescence: A Retrospective Cohort Study Comparing American Indians/Alaska Natives and Non-Hispanic Whites

BackgroundAmerican Indians and Alaska Natives have the highest obesity prevalence in the United States, but the influence of early childhood variables on body mass index (BMI; calculated as kg/m2) is not well understood. Previous studies have investigated the association between breastfeeding in infancy and offspring BMI, but rarely included American Indians and Alaska Natives. ObjectiveThis study investigated the association between breastfeeding in infancy and BMI in American Indians and Alaska Native and non-Hispanic white adolescents and young adults. DesignLongitudinal analysis based on data from the National Longitudinal Study of Adolescent to Adult Health (1994 to 2008). ParticipantsAdolescent respondents who self-identified as American Indians and Alaska Native or non-Hispanic white, and whose parents completed the parental questionnaire, reported their height and weight. The final sample included 655 American Indians and Alaska Native and 10,305 non-Hispanic white respondents. Statistical analyses performedGeneralized estimating equations were used to measure the mean differences, 95% CIs, and P values of the association between breastfeeding in infancy and offspring BMI in adolescence, stratifying by race, and adjusting for demographic and socioeconomic variables. ResultsThe length of breastfeeding was inversely associated with BMI in both populations. American Indians and Alaska Natives that were breastfed for 6 to 12 months or for more than 12 months had a mean BMI of 2.69 (95% CI −3.46 to −1.92; P<0.01) and 1.54 (95% CI −2.75 to −0.33; P<0.05) units lower than those that were never breastfed. Non-Hispanic whites that were breastfed for 3 to 6 months, 6 to 12 months, or more than 12 months had a mean BMI of 0.71 (95% CI −0.93 to −0.50; P<0.01), 0.68 (95% CI −0.87 to −0.50; P<0.01), and 0.85 (95% CI −1.09 to −0.62; P<0.01) units lower than those that were never breastfed. The association between the length of breastfeeding and offspring BMI varied by race (P<0.01). ConclusionsBreastfeeding in infancy is associated with lower mean BMI. Future research should investigate causal pathways and whether interventions promoting breastfeeding in American Indians and Alaska Natives can prevent increasing BMI.

Infant BMI or Weight-for-Length and Obesity Risk in Early Childhood.

Weight-for-length (WFL) is currently used to assess adiposity under 2 years. We assessed WFL- versus BMI-based estimates of adiposity in healthy infants in determining risk for early obesity. Anthropometrics were extracted from electronic medical records for well-child visits for 73 949 full-term infants from a large pediatric network. World Health Organization WFL and BMI z scores (WFL-z and BMI-z, respectively) were calculated up to age 24 months. Correlation analyses assessed the agreement between WFL-z and BMI-z and within-subject tracking over time. Logistic regression determined odds of obesity at 2 years on the basis of adiposity classification at 2 months. Agreement between WFL-z and BMI-z increased from birth to 6 months and remained high thereafter. BMI-z at 2 months was more consistent with measurements at older ages than WFL-z at 2 months. Infants with high BMI (≥85th percentile) and reference WFL (5th-85th percentiles) at 2 months had greater odds of obesity at 2 years than those with high WFL (≥85th percentile) and reference BMI (5th-85th percentiles; odds ratio, 5.49 vs 1.40; P < .001). At 2 months, BMI had a higher positive predictive value than WFL for obesity at 2 years using cut-points of either the 85th percentile (31% vs 23%) or 97.7th percentile (47% vs 29%). High BMI in early infancy is more strongly associated with early childhood obesity than high WFL. Forty-seven percent of infants with BMI ≥97.7th percentile at 2 months (versus 29% of infants with WFL ≥97.7th percentile at 2 months) were obese at 2 years. Epidemiologic studies focused on assessing childhood obesity risk should consider using BMI in early infancy.

Weight Gain Velocity of Formula Fed Infants And Risk of Overweight at Age 5 Years

Rapid weight gain during infancy has been associated with overweight and obesity later in life. However, the role of weight gain velocity (WGV) during infancy on adiposity later in life while controlling for dietary intake during infancy has not been well examined. This study characterized infant WGV and risk of overweight and adiposity in 152 healthy 5‐year‐old children that were fed either cow milk‐based (N=75) or soy‐based (N=77) formula during infancy. Body composition was assessed using Dual‐energy X‐ray Absorptiometry. Dietary intake was measured using 3‐days food records analyzed with the Nutrition Data System for Research. Linear regression models were used to assess the association between WGV during infancy and adiposity measurements at age 5, controlling for gestational age, birth weight, birth length, infant sex, caloric intake during infancy and maternal BMI. There were no differences observed between the two formula groups. WGV during the first year of life was significantly and positively associated with BMI‐for‐age z‐scores (β =1.01, p&lt;0.001), with % body fat (β =5.72, p=0.001) and with overall body fat mass (β =1.96, p=0.001). These associations were stronger when rapid growth occurred between 6 and 9 months of age. These results indicate that rapid weight gain during infancy is an independent risk factor for overweight and higher adiposity at age 5, even after controlling for important covariates such as maternal BMI and caloric intake during infancy. These results are likely driven by differences in energy expenditure or metabolism that are exacerbated during the period of introduction of solid foods. Funded by USDA‐ARS CRIS # 6251‐51000‐005‐03S

Timing of Solid Food Introduction and Obesity: Hong Kong’s “Children of 1997” Birth Cohort

Some observational studies in Western settings show that early introduction of solid food is associated with subsequent obesity. However, introduction of solid food and obesity share social patterning. We examined the association of the timing of the introduction of solid food with BMI and overweight (including obesity) into adolescence in a developed non-Western setting, in which childhood obesity is less clearly socially patterned. We used generalized estimating equation models to estimate the adjusted associations of the timing of the introduction of solid food (<3, 3-4, 5-6, 7-8, and >8 months) with BMI z score and overweight (including obesity) at different growth phases (infancy, childhood, and puberty) in 7809 children (88% follow-up) from a Chinese birth cohort, "Children of 1997." We assessed if the associations varied with gender or breastfeeding. We used multiple imputation for missing exposure and confounders. The introduction of solid food at <3 months of age was associated with lower family socioeconomic position (SEP) but was not clearly associated with BMI or overweight (including obesity) in infancy [mean difference in BMI z score: 0.01; 95% confidence interval (CI): -0.14 to 0.17], childhood (0.14; 95% CI: -0.11 to 0.40), or at puberty (0.22; 95% CI: -0.07 to 0.52), adjusted for SEP and infant and maternal characteristics. In a non-Western developed setting, there was no clear association of the early introduction of solid food with childhood obesity. Together with the inconsistent evidence from studies in Western settings, this finding suggests that any observed associations might simply be residual confounding by SEP.

Child undernutrition in affluent societies: what are we talking about?

In this paper we set out to explore the prevalence of child undernutrition found in community studies in affluent societies, but a preliminary literature review revealed that, in the absence of a gold standard method of diagnosis, the prevalence largely depends on the measure, threshold and the growth reference used, as well as age. We thus go on to explore describe the common clinical 'syndromes' of child undernutrition: wasting, stunting and failure to thrive (weight faltering) and how we have used data from two population-based cohort studies, this paper to explore how much these different 'syndromes' overlap and the extent to which they reflect true undernutrition. This analysis revealed that when more than one definition is applied to the same children, a majority are below the lower threshold for only one measure. However, those with both weight faltering and low BMI in infancy, go on in later childhood to show growth and body composition patterns suggestive of previous undernutrition. In older children there is even less overlap and most children with either wasting or low fat seem to be simply growing at one extreme of the normal range. We conclude that in affluent societies the diagnosis of undernutrition is only robust when it relies on a combination of both, that is decline in weight or BMI centile and wasting.

Breastfeeding and Determinants of Adult Body Composition: A Prospective Study from Birth to Young Adulthood

Background: The impact of breastfeeding on adult body composition is controversial. We evaluated effects of lifestyle and childhood-related factors, including infant feeding, on adult body composition. Methods: We determined total body and trunk fat and lean mass by densitometry in 158 adults who were born full-term and prospectively followed from birth to the age of 32 years. Data on various factors, extending from infancy to adulthood, with potential effect on body composition, were recorded. Results: Scapular skinfold thickness at 12 months correlated with adult trunk (R = 0.22, p = 0.005) and body fat percentage (R = 0.18, p = 0.023). In linear regression analysis, current physical activity (R = –0.33, p < 0.001) and maternal BMI (R = 0.28, p = 0.002) were associated with adult body fat percentage. Gender (R = 0.78, p < 0.001) and weight gain during infancy (R = 0.147, p = 0.008) were associated with adult lean mass. In the analysis of covariance, prolonged breastfeeding tended to lead to lower fat percentage in adulthood, but no direct association with the duration of breastfeeding and adult body composition was confirmed. Conclusions: Current physical activity, growth in infancy, gender and maternal BMI influence adult body composition. Breastfeeding has an indirect influence on adult body fat accumulation by affecting growth and body adiposity in infancy.

Association between Common Variation at the FTO Locus and Changes in Body Mass Index from Infancy to Late Childhood: The Complex Nature of Genetic Association through Growth and Development

An age-dependent association between variation at the FTO locus and BMI in children has been suggested. We meta-analyzed associations between the FTO locus (rs9939609) and BMI in samples, aged from early infancy to 13 years, from 8 cohorts of European ancestry. We found a positive association between additional minor (A) alleles and BMI from 5.5 years onwards, but an inverse association below age 2.5 years. Modelling median BMI curves for each genotype using the LMS method, we found that carriers of minor alleles showed lower BMI in infancy, earlier adiposity rebound (AR), and higher BMI later in childhood. Differences by allele were consistent with two independent processes: earlier AR equivalent to accelerating developmental age by 2.37% (95% CI 1.87, 2.87, p = 10−20) per A allele and a positive age by genotype interaction such that BMI increased faster with age (p = 10−23). We also fitted a linear mixed effects model to relate genotype to the BMI curve inflection points adiposity peak (AP) in infancy and AR. Carriage of two minor alleles at rs9939609 was associated with lower BMI at AP (−0.40% (95% CI: −0.74, −0.06), p = 0.02), higher BMI at AR (0.93% (95% CI: 0.22, 1.64), p = 0.01), and earlier AR (−4.72% (−5.81, −3.63), p = 10−17), supporting cross-sectional results. Overall, we confirm the expected association between variation at rs9939609 and BMI in childhood, but only after an inverse association between the same variant and BMI in infancy. Patterns are consistent with a shift on the developmental scale, which is reflected in association with the timing of AR rather than just a global increase in BMI. Results provide important information about longitudinal gene effects and about the role of FTO in adiposity. The associated shifts in developmental timing have clinical importance with respect to known relationships between AR and both later-life BMI and metabolic disease risk.

Infant growth disparity in the Khanh Hoa province in Vietnam: a follow-up study

BackgroundSurveys in Vietnam have indicated that wasting and stunting have been prevalent among children, but the country is undergoing rapid socio-economic changes and little has been known about the relative situation in the different areas of the country. In 2006, the WHO introduced new growth standards applicable to all infant and child populations, which facilitates for improved assessments of the prevalence of growth impairment, independent of time, place and ethnicity. The aim of our study was to assess the growth of singleton infants delivered at term in three main birth clinics in the Khanh Hoa province in Vietnam by using the new WHO standards as reference, and the association between growth and some maternal, birth and health factors.MethodsA cohort of 237 singleton infants born in the period May-July 2005 in three main delivery clinics in the Khanh Hoa province were observed prospectively. Their anthropometrical measures a year later were compared to the WHO sex-specific growth standards for weight-for-age, length-for-age, weight-for-length, and BMI-for-age. These measures were analysed as dependent outcomes using multiple linear regression models including the following independent factors: urban vs. rural birth, 1-minute Apgar score, weight and length at birth, duration of lactation, ever had diarrhoea, dengue fever, pneumonia or dysentery, and maternal age, height, gestational duration and parity.ResultsCompared to the standard distributions, 79% were below the median for weight-for-length; 18.0% were within the 5th percentile for length-for-age, 9.6% for weight-for-age, 20.3% for weight-for-length, and 19.8% for BMI. A lower length- and weight-for-age were statistically associated with being born rurally.ConclusionsIn this delivery-clinic based sample of children in the Khanh Hoa province in Vietnam, the proportions within the WHO-standard 5th percentiles for length-for-age, weight-for-length and BMI in late infancy were 3-4 times higher than expected, which indicate that deficient growth is prevalent. The infants born in a rural area had a lower weight- and length-for-age than their urban counterparts, independent of diarrhoea.

Infant weight gain, duration of exclusive breast-feeding and childhood BMI – two similar follow-up cohorts

To describe the association between duration of exclusive breast-feeding (EBF), weight gain in infancy and childhood BMI in two populations with a long duration of EBF. Cohort study with follow-up in childhood. Breast-feeding status was reported monthly during infancy. Weight and length were measured at birth, 2, 6 and 12 months of age, as well as in childhood at 6 or 10 years of age. Iceland and Denmark. Randomly selected healthy newborns from Denmark (n 85) and Iceland (n 100). Infants exclusively breast-fed for < or =2 months gained 348 (95% CI 69, 626) g more weight from 2 to 6 months than infants exclusively breast-fed for 3-4 months (P = 0.009). Weight gain from 6 to 12 months was found to be greater among infants exclusively breast-fed for < or =2 months compared with those exclusively breast-fed for > or =5 months (P = 0.008). A greater weight change, in terms of Z-score, between the ages of 2 and 6 months was associated with higher Z-score of childhood BMI, adjusted for birth weight, country and duration of EBF (B = 0.49, se = 0.11, P < 0.001, adj. R2 = 0.15). However, the association was much stronger in the Icelandic cohort than the Danish one. Although duration of EBF was not associated with childhood BMI in the present study it may modulate growth rate in infancy, which is related to childhood BMI. However, other factors determinative for infant growth also need to be considered when assessing the relationship of early growth and nutrition to childhood overweight, as traditions in complementary food might differ between populations.