title: Significant sex difference in the association between C-reactive protein concentration and anthropometry among 13- to 19-year olds, but not 6- to 12-year olds in Nepal.
abstract: Life history theory predicts a trade-off between immunostimulation and growth. Using a cross-sectional study design, this study aims to test the hypothesis that C-reactive protein (CRP) is negatively associated with height-for-age z-scores (HAZ scores) and BMI-for-age z-scores (BAZ scores) among 6- to 19-year olds (N = 426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in-house enzyme immunoassay (EIA). Sex- and age-group-specific CRP quartiles were used to examine its association with growth in linear mixed-effects (LME) models. A significant difference was found in the proportion of elevated CRP (>2 mg/L, equivalent to ∼3.2 mg/L serum CRP) between 13- and 19-year-old boys (12%) and girls (4%). Concentrations of CRP were positively associated with HAZ score among adolescent (13-19 years) boys, which may indicate that individuals with greater energy resources have better growth and a better response to infections, thus eliminating the expected trade-off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggesting that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a positive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low-grade inflammation due to body fat rather than infection. The association between CRP and growth was less evident among children (6-12 years) compared with adolescents, indicating that the elevated energy requirement needed for the adolescent growth spurt and puberty may play some role.
authors.affiliation: Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan; Department of Anthropology, University of Washington, Seattle, WA, 98195.
authors.forename: Shoko
authors.initials: S
authors.lastname: Konishi
authors.forename: Rajendra Prasad
authors.initials: RP
authors.lastname: Parajuli
authors.forename: Erica
authors.initials: E
authors.lastname: Takane
authors.forename: Makhan
authors.initials: M
authors.lastname: Maharjan
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Tachibana
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Jiang
authors.forename: Krishna
authors.initials: K
authors.lastname: Pahari
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Inoue
authors.forename: Masahiro
authors.initials: M
authors.lastname: Umezaki
authors.forename: Chiho
authors.initials: C
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D000885:Anthropology, Physical; D001827:Body Height / Q000502:physiology*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis*; D002648:Child; D059788:Dried Blood Spot Testing; D005260:Female; D006801:Humans; D008297:Male; D009390:Nepal / Q000453:epidemiology; D012737:Sex Factors; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein
keywords: BMI; dried blood spot; height; inflammation