Mean BMI-for-age <i>z</i> score in urban Amazonian children with complete C-reactive protein and anthropometric information, according to age groups and baseline characteristics (2007).

a<p>Totals may be less than 469 for children ≤5 years and less than 538 for children >5 years at baseline because of missing values.</p>b<p>Results are mean BMI-for age <i>z</i> score (BAZ) and standard deviation (SD).</p>c<p>BMI-for-age and height-for-age <i>z</i> scores calculated according to the WHO Child Growth Standards for children ≤5 years and the WHO Growth Reference Data for children >5 years.</p>d<p>Test for linear trend for ordinal predictors; for dichotomous predictors, Wilcoxon rank-sum test.</p>e<p>Information on food frequency index for fruit and vegetable consumption was available for children >4 years only.</p>f<p>C-reactive protein was categorized as tertiles below 1 mg/L and >1 mg/L. Categories were distributed as follows: 1^st tertile: 0.01–0.15 mg/L; 2^nd tertile: 0.16–0.38 mg/L; 3^rd tertile: 0.39–1.00 mg/L; >1 mg/L: 1.01–9.81 mg/L. Children with C-reactive protein values >10 mg/L were excluded from the analyses (<i>n</i> = 41).</p

Multiple linear regression analysis of baseline predictors of log-transformed C-reactive protein (mg/L) among urban Amazonian children.

a<p>Totals are 438 for children ≤5 years and 511 for children >5 years at baseline because of missing values.</p>b<p>β coefficients and their 95% confidence intervals (CI) were from linear regression models. <i>P</i><0.05 for results in bold.</p

C-Reactive Protein Concentration Predicts Change in Body Mass Index during Childhood

<div><p>Objective</p><p>Inflammation may constitute an underlying mechanism for increased risk of developing chronic diseases in later years, but few prospective studies have assessed the influence of low-grade inflammation on body weight gain, particularly among children in low- to middle-income settings with lower prevalence of overweight and obesity. We aimed to investigate whether C-reactive protein (CRP), as a biomarker of low-grade inflammation, predicts changes in body mass index-for-age <i>z</i> scores (BAZ) during childhood.</p><p>Methods</p><p>A population-based longitudinal study was conducted in the Brazilian Amazon among children aged ≤10 years in 2007, with follow-up visits in 2009 and 2012. Outcome was annual change in BAZ. As the main exposure of interest, CRP concentrations were divided into four categories, with values <1 mg/L divided in tertiles plus a fourth category with values ranging from 1 to 10 mg/L. Children were simultaneously screened for iron and vitamin A deficiencies, diarrhea, and wheezing. We used mixed-effect linear regression models to measure the effect of CRP concentrations on annual BAZ change and linear regression models to explore CRP predictors at baseline.</p><p>Results</p><p>At baseline, 1007 children had CRP and anthropometric data [mean (SD) age: 5.3 (2.9) years; 50.9% male, 84.5% mulatto/mixed-race, 14.0% at risk for overweight or obesity, 4.8% stunted]; 737 were successfully followed up. Morbidities and nutritional deficiencies were widespread. Among participants aged >5 years, children in the highest tertile of CRP <1 mg/L at baseline, regarded as an indicator of low-grade inflammation, had a 0.04 <i>z</i>/y higher gain in BAZ (95% CI: 0.01, 0.09 <i>z</i>/y) during follow-up. CRP was positively associated with household poverty and worse nutritional indicators.</p><p>Conclusions</p><p>We found evidence of a role for low-grade inflammation in predicting annual BAZ gain among children aged >5 years.</p></div

Differences in BMI-for-age <i>z</i> score change per year over childhood among urban Amazonian children (2007–2012), according to age groups and baseline health indicators.

a<p>Totals may be less than 346 for children ≤5 years and less than 391 for children >5 years at baseline because of missing values. Missing observations among the covariates were included in the multiple models by creating missing-value categories.</p>b<p>BMI-for-age <i>z</i> scores (BAZ) were calculated according to the WHO Child Growth Standards for children ≤5 years and the WHO Growth Reference Data for children >5 years.</p>c<p>Mean differences in BAZ change per year and their 95% confidence intervals (CI) were from mixed-effect linear regression models. For each age group, unadjusted differences refer to preliminary models that included each child health indicator with adjustment for sex. Fully adjusted differences were estimated from models including CRP and all other health indicators with further adjustment for household wealth, maternal age, birth weight, and HAZ at baseline. <i>P</i><0.05 for results in bold.</p>d<p>C-reactive protein categories were distributed as follows: 1^st tertile: 0.01–0.15 mg/L; 2^nd tertile: 0.16–0.38 mg/L; 3^rd tertile: 0.39–1.00 mg/L; >1 mg/L: 1.01–9.81 mg/L.</p

General characteristics of urban Amazonian children at each study assessment.

a<p>Totals may be less than numbers indicated in brackets for each study assessment because of missing values.</p>b<p>BMI-for-age and height-for-age <i>z</i> scores calculated according to the WHO Child Growth Standards for children ≤5 years and the WHO Growth Reference Data for children >5 years.</p

General characteristics of children aged 6 months to 10 years (N = 1111).

a<p>Totals differ from the total number of study children because of missing values.</p

Attributable fractions (AF) of anemia according to age group in urban Amazonian children.

a<p>Prevalence (%) of cases exposed in each risk factors.</p>b<p>Adjusted prevalence ratio (aPR) estimated from multiple Poisson regression models with additional adjustment for age (in overall analysis), sex, wealth index (quartile), maternal schooling (≤4, 5–8, and ≥9 years), and maternal age (10–21, 22–35, and >35 years).</p>c<p>Attributable fraction defined as p(aPR –1)/aPR.</p

Iron status indicators and prevalence of anemia and other nutritional and non-nutritional conditions in urban Amazonian children^a.

<p>IQR, interquartile ranges.</p>a<p>Totals in brackets differ from the total number of study children by age group because of missing values.</p>b<p>Cut-offs for anemia: <110.0 and <115.0 g/L for 6–59 months and ≥60 months, respectively;</p>c<p>Cut-offs for microcytosis by age: <67, <73, <74, and <76 fl for <24 months, 24–59 months, 5–7.9 years, and 8–11.9 years, respectively;</p>d<p>PF: <12 and <15 µg/L for <59 and ≥60 months, respectively;</p>e<p>sTfR: >8.3 mg/L;</p>f<p>Cut-off for high CRP: >5 mg/L;</p>g<p>CRP index defined as (0.34+0.0043×PF – [2.7×sTfR]/PF+0.00696×CRP+0.05×sTfR);</p>h<p>Serum retinol <0.70µmol/L;</p>i<p>Serum vitamin B₁₂<150 pmol/L;</p>j<p>Serum folate <10 nmol/L;</p>k<p>According to cut-offs for PF or sTfR.</p>l<p>Geohelminths in this population included <i>Ascaris lumbricoides</i> (overall prevalence, 2.4%), <i>Strongyloides stercoralis</i> (0.5%), and <i>Trichuris trichiura</i> (0.8%) - the same subject may be co-infected with more than one species.</p

Multiple linear regression analysis of factors associated with hemoglobin in urban Amazonian children.

a<p>Total differs from total number of study children because of missing values.</p

Frequency (%) of iron deficiency (<i>A</i>), iron deficiency anemia (<i>B)</i> and vitamin A deficiency (<i>C</i>) stratified by inflammation status using combined plasma values of CRP and AGP according to ENFAC study groups.

<p>Reference, CRP ≤ 5mg/L and AGP ≤ 1g/L, <i>n</i> = 302 (<i>A</i> and <i>B</i>) or 296 (<i>C</i>) in CG, and <i>n</i> = 275 (<i>A</i> and <i>B</i>) or 274 (<i>C</i>) in IG; Chronic, CRP ≤ 5mg/L and AGP> 1g/L, <i>n</i> = 83 (<i>A</i> and <i>B</i>) or 84 (<i>C</i>) in CG, and <i>n</i> = 59 (<i>A</i>, <i>B</i> or <i>C</i>) in IG; Acute, CRP >5 and AGP> 1g/L mg/L, <i>n</i> = 68 (<i>A</i> and <i>B</i>) or 65 (<i>C)</i> in CG, and <i>n</i> = 30 (<i>A</i> and <i>B</i>) or 27 (<i>C</i>) in IG. Totals differ from the total number of study children due to missing values for biochemical indicators. The symbol * indicates significant differences for the IG compared with CG (Pearson χ² test). AGP, α-1-acid glycoprotein; CG, control group; CRP, C-reactive protein; ENFAC, <i>Estudo Nacional de Fortificação caseira da Alimentação Complementar;</i> IG, intervention group.</p