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Objective: The aim of this study was to investigate the relationship of BMI with subsequent statural growth among children born in the era of the obesity epidemic.Methods: Among 18,271 children from Belarus (n = 16,781, born 1996 to 1997) and the United States (n = 1,490, born 1999 to 2002), multivariable linear and ordinal logistic regression was used to analyze associations of BMI z score from infancy to adolescence with subsequent standardized length and height velocity, standing height and its components (trunk and leg lengths), and pubertal timing.Results: The prevalence of early adolescent obesity was 6.2% in Belarus and 12.8% in the United States. In both Belarusian and US children, higher BMI z scores in infancy and childhood were associated with faster length and height velocity in early life, while higher BMI z scores during middle childhood were associated with slower length and height velocity during adolescence. Associations with greater standing height and trunk length and earlier pubertal development in adolescence were stronger for BMI z scores at middle childhood than BMI z scores at birth or infancy.Conclusions: These findings in both Belarus and the United States support the role of higher BMI in accelerating linear growth in early life (taller stature and longer trunk length) but earlier pubertal development and slower linear growth during adolescence. [ABSTRACT FROM AUTHOR]

Objective: The Children's Eating Attitudes Test (ChEAT) is a self‐report questionnaire that is conventionally summarized with a single score to identify "problematic" eating attitudes, masking informative variability in different eating attitude domains. This study evaluated the empirical support for single‐ versus multifactor models of the ChEAT. For validation, we compared how well the single‐ versus multifactor‐based scores predicted body mass index (BMI). Method: Using data from 13,674 participants of the 11.5 year‐follow‐up of the Promotion of Breastfeeding Intervention Trial (PROBIT) in the Republic of Belarus, we conducted confirmatory factor analysis to evaluate the performance of 3‐ and 5‐factor models, which were based on past studies, to a single‐factor model representing the conventional summary of the ChEAT. We used cross‐validated linear regression models and the reduction in mean squared error (MSE) to compare the prediction of BMI at 11.5 and 16 years by the conventional and confirmed factor‐based ChEAT scores. Results: The 5‐factor model, based on 14 of the original 26 ChEAT items, had good fit to the data whereas the 3‐ and single‐factor models did not. The MSE for concurrent (11.5 years) BMI regressed on the 5‐factor ChEAT summary was 35% lower than that of the single‐score models, which reduced the MSE from the null model by only 1%–5%. The MSE for BMI at 16 years was 20% lower. Discussion: We found that a parsimonious 5‐factor model of the ChEAT explained the data collected from healthy Belarusian children better than the conventional summary score and thus provides a more discriminating measure of eating attitudes. [ABSTRACT FROM AUTHOR]

Recent studies finding that small-for-gestational-age (SGA) birth is associated with increased adiposity in childhood and adulthood have been based on analyses "adjusting" for height, weight, or body mass index (BMI; weight (kg)/height (m)²) measured concurrently with the adiposity measurement. To assess the potential for bias due to overadjustment for a causal mediator, we compared 2 approaches to analyzing the association between SGA birth and adiposity outcomes (skinfold thicknesses and bioelectrical impedance measurement of body fat) at age 11.5 years using the same data set in a cohort of Belarusian children followed from birth in 1996-1997 to age 11.5 years in 2008-2010. We 1) studied the association of SGA birth with adiposity, adjusting for baseline covariates only, and 2) made additional regression adjustment for concurrent height, weight, or BMI. The first approach yielded negative associations between SGA birth and all adiposity outcomes. Additional adjustment for concurrent weight or BMI reversed (i.e., to positive) the SGA-adiposity association. To explore the latter anthropometric measures as causal mediators, we also used marginal structural models to estimate the controlled direct effect of SGA birth. That effect was similar to the effect seen with the first approach when modeled on height, was null when modeled on BMI, but was confounded by differences in lean mass versus fat mass when modeled on weight. [ABSTRACT FROM AUTHOR]

Background: Several recent "developmental origins" studies have reported increased long-term risks of adiposity, especially truncal adiposity, among children born small for gestational age (SGA). Objective: We assessed the effects of SGA birth and weight gain in early infancy on adiposity at age 11.5 y. Design: From a cluster-randomized breastfeeding promotion trial in 17,046 Belarusian children, we measured height, weight, waist and hip circumferences, triceps and subscapular skinfold thicknesses, and bioimpedance measures of percentage body fat at age 11.5 y. Children born SGA (birth weight <10th percentile) and those born large for gestational age (LGA; >90th percentile for gestational age) were compared with those born appropriate for gestational age (AGA). Weight gain from birth to 6 mo was categorized as high (>0.67-SD increase in weight-for-age), low (>0.67-SD decrease in weight-forage), or normal. Multilevel statistical models accounted for clustered measurement and controlled for maternal and paternal height and body mass index (BMI), maternal education, geographic region, urban compared with rural residence, and the child's exact age at follow-up. Results: Children born SGA had a significantly lower BMI, percentage body fat, and fat mass index than did those born AGA, with a dose-response effect across 2 subcategories of SGA (P<0.001 for all comparisons). No difference was observed in waist-to-hip ratio, although the subscapular-to-triceps skinfold ratio was slightly but significantly (P<0.001) higher in children born SGA. Differences among the study groups continued to increase since the previous follow-up at 6.5 y. SGA infants with catch-up growth in the first 3-6 mo had growth and adiposity measures intermediate between those born SGA without catch-up and those born AGA. Opposite effects of similar magnitude were observed in children born LGA. Conclusion: The 11.5-y-old Belarusian children born SGA were shorter, were thinner, and had less body fat than their non-SGA peers, irrespective of postnatal weight gain. [ABSTRACT FROM AUTHOR]

Background: Differences between mothers who do and do not succeed in breastfeeding are likely to confound associations of lactation with later maternal adiposity. Objective: We compared adiposity and blood pressure (BP) in women randomly assigned to an intervention to promote prolonged and exclusive breastfeeding or usual care. Design: We performed a cluster-randomized trial at 31 hospitals in Belarus in 19961997. Results: Of 17,046 women enrolled at delivery, we assessed 11,867 women (69.6%) at 11.5 y postpartum. The prevalence of exclusive breastfeeding ±3 mo was 44.5% in 6321 women in the intervention group and 7.1% in 5546 women in the control group. At 11.5 y postpartum, mean (6SD) body mass index (BMI; in kg/m²) was 26.5 ± 5.5, the percentage of body fat was 33.6% ± 8.3%, and systolic BP was 124.6 ± 14.6 mm Hg. On intention-to-treat analysis (without imputation) with adjustment for clustering by hospital, mean outcomes were lower in intervention compared with control mothers for BMI (mean difference: -0.27; 95% CI: -0.91, 0.37), body fat (-0.49%; 95% CI: -1.25%, 0.27%), and systolic BP (-0.81 mm Hg; 95% CI: -3.33, 1.71 mm Hg), but effect sizes were small, CIs were wide, and results were attenuated further toward the null after adjustment for baseline characteristics. Results were similar in sensitivity analyses [ie, by using conventional observational analyses disregarding treatment assignment, instrumental variable analyses to estimate the causal effect of breastfeeding, and multiple imputation to account for missing outcome measures (n = 17,046)]. Conclusion: In women who initiated breastfeeding, an intervention to promote longer breastfeeding duration did not result in an important lowering of adiposity or BP. This trial was registered at clinicaltrials.gov as NCT01561612 and at Current Controlled Trials as ISRCTN37687716. [ABSTRACT FROM AUTHOR]

The article focuses on a randomized-controlled trial which aims to investigate effects of an intervention to promote increased duration and exclusivity of breastfeeding on child adiposity and circulating insulin-like growth factor (IGF)-I in Belarus. It mentions that the participants of this study included 17,046 breastfeeding mothers enrolled in 1996 and 1997, of whom 13,879 were followed up between January 2008 and December 2010 at a median age of 11.5 years. The main outcome measures included body mass index, percent body fat and waist circumference. The results indicated that breastfeeding has many advantages but population strategies to increase the duration and exclusivity of breastfeeding are unlikely to curb the obesity epidemic.

Background: In large-scale epidemiology, bloodspot sampling by fingerstick onto filter paper has many advantages, including ease and low costs of collection, processing and transport. We describe the development of an enzyme-linked immunoassay (ELISA) for quantifying insulin from dried blood spots and demonstrate its application in a large trial. Methods: We adapted an existing commercial kit (Mercodia Human Insulin ELISA, 10-1113-01) to quantify insulin from two 3-mm diameter discs (≈6 µL of blood) punched from whole blood standards and from trial samples. Paediatricians collected dried blood spots in a follow-up of 13,879 fasted children aged 11.5 years (interquartile range 11.3-11.8 years) from 31 trial sites across Belarus. We quantified bloodspot insulin levels and examined their distribution by demography and anthropometry. Results: Mean intra-assay (n = 157) coefficients of variation were 15% and 6% for 'low' (6.7 mU/L) and 'high' (23.1 mU/L) values, respectively; the respective inter-assay values (n = 33) were 23% and 11%. The intraclass correlation coefficient between 50 paired whole bloodspot versus serum samples, collected simultaneously, was 0.90 (95% confidence interval 0.85 to 0.95). Bloodspot insulin was stable for at least 31 months at -80°C, for one week at +30°C and following four freeze-thaw cycles. Paediatricians collected a median of 8 blood spots from 13,487 (97%) children. The geometric mean insulin (log standard deviation) concentrations amongst 12,812 children were 3.0 mU/L (1.1) in boys and 4.0 mU/L (1.0) in girls and were positively associated with pubertal stage, measures of central and peripheral adiposity, height and fasting glucose. Conclusions: Our simple and convenient bloodspot assay is suitable for the measurement of insulin in very small volumes of blood collected on filter paper cards and can be applied to large-scale epidemiology studies of the early-life determinants of circulating insulin. [ABSTRACT FROM AUTHOR]

Background: Weight gain during infancy may programme later health outcomes, but examination of this hypothesis requires appropriate lifecourse methods and detailed weight gain measures during childhood. We examined associations between weight gain in infancy and early childhood and blood pressure at the age of 6.5 years in healthy children born at term.Methods: We carried out an observational analysis of data from a cluster-randomized breastfeeding promotion trial in Belarus. Of 17 046 infants enrolled between June 1996 and December 1997, 13 889 (81.5%) had systolic and diastolic blood pressure measured at 6.5 years; 10 495 children with complete data were analysed. A random-effects linear spline model with three knot points was used to estimate each individual's birthweight and weight gain from birth to 3 months, 3 months to 1 year and 1-5 years. Path analysis was used to separate direct effects from those mediated through subsequent weight gain.Results: In boys, after controlling for confounders and prior weight gain, the change in systolic blood pressure per z-score increase in weight gain was 0.09 mmHg [95% confidence interval (95% CI) -0.14 to 0.31] for birthweight; 0.41 mmHg (95% CI 0.19-0.64) for birth to 3 months; 0.69 mmHg (95% CI 0.47-0.92) for 3 months to 1 year and 0.82 mmHg (95% CI 0.58-1.06) for 1-5 years. Most of the associations between weight gain and blood pressure were mediated through weight at the age of 6.5 years. Findings for girls and diastolic blood pressure were similar.Conclusions: Children who gained weight faster than their peers, particularly at later ages, had higher blood pressure at the age of 6.5 years, with no association between birthweight and blood pressure. [ABSTRACT FROM AUTHOR]

Background: Lower socioeconomic position is associated with shorter stature, in particular shorter leg length, but the magnitude of these associations in non-Western countries has received little attention. Aim: To examine socioeconomic differentials in height, leg and trunk length in 6.5 year olds from the Republic of Belarus and compare these to differentials in parental height. Methods: Multivariable linear regression was used to examine associations in a cohort of 13 889 children. Results: Children from non-manual households were 1.0  cm (95% confidence interval: 0.7--1.3  cm) taller than those from manual households. Mothers and fathers from non-manual backgrounds were 0.7  cm (0.5--0.8) and 1.8  cm (1.6--2.0) taller than those from manual backgrounds, respectively. Associations with higher parental educational attainment were similar. The magnitudes of the associations of socioeconomic position with leg length were similar to those with trunk length. Adjusting for mid-parental height and number of older siblings attenuated associations markedly. Conclusions: In Belarus, similar socioeconomic differentials in height were observed in both children and their parents. Among children, height differentials were partly explained by mid-parental height and number of older siblings. Leg length was not a more sensitive indicator of childhood socioeconomic conditions than trunk length. [ABSTRACT FROM AUTHOR]

Background: Socio-economic differences in the prevalence of overweight/obesity may be one factor through which health inequalities arise and may vary by the population studied. Methods: Analysing a cohort of 13 889 children born in Belarus between June 1996 and December 1997, the authors investigated associations of parental educational attainment and highest household occupation with: (i) measured body mass index (BMI), waist circumference and skinfold thicknesses at age 6.5 years and (ii) the parents’ reported BMI. Results: Overall, 10% of children, 37% of mothers and 53% of fathers were either overweight or obese. Children from non-manual households were 27% [95% confidence interval (CI): 10%, 47%] more likely to be overweight/obese (based on BMI) than those from manual households. They also had larger waist circumferences and higher percentage body fat (calculated from subscapular and triceps skinfolds). Similar associations for being overweight/obese were seen for fathers [odds ratio (OR), 1.10; 95% CI: 1.02, 1.18], but mothers from non-manual households were less likely to be overweight/obese: (OR, 0.84; 95% CI: 0.79, 0. 90). Associations of childhood and parental overweight/obesity with higher educational status of either parent were similar to those observed for non-manual households. Conclusion: We observed socio-economic differentials in overweight/obesity prevalence among children and their parents in Belarus. More affluent children and their fathers were more likely to be overweight/obese but the reverse was found for mothers. [ABSTRACT FROM AUTHOR]

The evidence that breast-feeding protects against obesity is based on observational studies, with potential for confounding and selection bias. This article summarizes a previously published study in which we assessed whether an intervention designed to promote exclusive and prolonged breast-feeding affects children's height, weight, adiposity, and blood pressure (BP) at age 6.5 y. The Promotion of Breastfeeding Intervention Trial (PROBIT) a cluster-randomized trial of a breast-feeding promotion intervention based on the WHO/UNICEF Baby-Friendly Hospital Initiative. A total of 17,046 healthy breast-fed infants were enrolled from 31 Belarussian maternity hospitals and affiliated clinics, of whom 13,889 181.5%) were followed up at 6.5 y with duplicate measurements of height, weight, waist circumference, triceps and subscapular skinfold thicknesses, systolic and diastolic BP. Analysis was based on intention to treat, with statistical adjustment for clustering within hospitals/clinics to permit inferences at the individual level. The experimental intervention led to a large increase in exclusive breast-feeding at 3 mo (43.3% vs. 6.4%, P < 0.001) and a significantly higher prevalence of any breast-feeding throughout infancy. No significant intervention effects were observed on height, BMI, adiposity measures, or BP. The breast-feeding promotion intervention resulted in substantial increases in the duration and exclusivity of breast-feeding yet did not reduce measures of adiposity at age 6.5 y. Previous reports of protective effects against obesity may reflect uncontrolled bias caused by confounding and selection. [ABSTRACT FROM AUTHOR]