Browsing by Author "Corvalán, Camila"

Now showing 1 - 10 of 10
  • No Thumbnail Available
    Item
    Anthropometric and bioimpedance equations for fat and fat-free mass in Chilean children 7-9 years of age
    (2021) Salazar, Gabriela; Leyton, Barbara; Aguirre Polanco, Carolina; Anziani, Alyerina; Weisstaub, Gerardo; Corvalán, Camila
    Assessing children's growth adequately is important due to the necessary prevention of adequate body composition, especially at pre-pubertal age. Simpler measurements such as anthropometry or bioimpedance, using equations validated in Caucasian children, have been demonstrated to overestimate or underestimate fat mass percentage (FM%) or fat-free mass (FFM) in Chilean children. In a sample of 424 children (198 boys and 226 girls) of 7-9 years old, the three component (3C) model was assessed, where total body water was determined by H-2 dilution and body volume by air displacement plethysmography, in order to design and validate anthropometry and bioimpedance equations. The FM (%) equation specific for Chilean children was validated as (1 center dot 743 x BMI z-score) + (0 center dot 727 x triceps skinfold) + (0 center dot 385 x biceps skinfold) + 15 center dot 985, against the 3C model (R (2) 0 center dot 79). The new FFM equation (kg) generated was (log FFM = (0 center dot 018 x age) + (0 center dot 047 x sex) + (0 center dot 006 x weight) + (0 center dot 027 x resistance) + 2 center dot 071), with an R (2) 0 center dot 93 (female = 1 and male = 2). The Bland-Altman analysis shows a mean difference of 0 center dot 27 (sd 3 center dot 5) for the FM% in the whole group as well as 0 center dot 004 (sd 0 center dot 9) kg is the mean difference for the bioelectrical impedance analysis (BIA) FFM (kg) equation. The new equations for FM (%) and FFM (kg) in Chilean children will provide a simple and valid tool for the assessment of body composition in cohort studies or to assess the impact of nutritional programmes or public policies.
  • Thumbnail Image
    Item
    Association between indicators of systemic inflammation biomarkers during puberty with breast density and onset of menarche
    (2020) Michels, Karin B.; Santos Martín, José Luis; Keller, Kristen; Pereira, Ana; Kim, Claire E.; Shepherd, John A.; Corvalán, Camila; Binder, Alexandra M.
    Abstract Background Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. Methods We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006–2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. Results In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7–48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10–32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1–5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0–3%) longer time to menarche in multivariable models. Conclusions Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.Abstract Background Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls. Methods We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006–2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche. Results In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7–48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10–32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1–5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0–3%) longer time to menarche in multivariable models. Conclusions Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.
  • Thumbnail Image
    Item
    Association between plasma leptin/adiponectin ratio and insulin resistance indexes in prepubertal children
    (2024) Bravo, Carolina; Mericq, Verónica; Pereira, Ana; Corvalán, Camila; Tobar, Hugo E.; Miranda, José Patricio; Santos, José Luis
  • Thumbnail Image
    Item
    Conceptual basis for prescriptive growth standards from conception to early childhood: present and future
    (2013) Uauy, Ricardo; Casanello Toledo, Paola Cecilia; Krause Leyton, Bernardo; Kuzanovic, Juan Pablo; Corvalán, Camila
  • Thumbnail Image
    Item
    Dairy intake in relation to breast and pubertal development in Chilean girls
    (2017) Gaskins, Audrey J.; Pereira, Ana; Quintiliano, Daiana; Shepherd, John A.; Uauy, Ricardo; Corvalán, Camila; Michels, Karin B.
  • Thumbnail Image
    Item
    Effectiveness on maternal and offspring metabolic control of a home-based dietary counseling intervention and DHA supplementation in obese/overweight pregnant women (MIGHT study) : a randomized controlled trial-Study protocol
    (2018) Garmendia, María Luisa; Corvalán, Camila; Casanello Toledo, Paola Cecilia; Araya, Marcela; Flores, Marcela; Bravo, Alfredo; Kusanovic, Juan Pedro; Olmos Coelho, Pablo Roberto; Uauy, Ricardo
  • Thumbnail Image
    Item
    Genetic determinants of serum bilirubin using inferred native American gene variants in Chilean adolescents
    (2024) Miranda Marín, José Patricio; Pereira, Ana; Corvalán, Camila; Miquel P., Juan Francisco; Alberti, Gigliola; Gana Ansaldo, Juan Cristóbal; Santos Martín, José Luis
    Gene variants in the UGT1A1 gene are strongly associated with circulating bilirubin levels in several populations, as well as other variants of modest effect across the genome. However, the effects of such variants are unknown regarding the Native American ancestry of the admixed Latino population. Our objective was to assess the Native American genetic determinants of serum bilirubin in Chilean admixed adolescents using the local ancestry deconvolution approach. We measured total serum bilirubin levels in 707 adolescents of the Chilean Growth and Obesity Cohort Study (GOCS) and performed high-density genotyping using the Illumina-MEGA array (>1.7 million genotypes). We constructed a local ancestry reference panel with participants from the 1000 Genomes Project, the Human Genome Diversity Project, and our GOCS cohort. Then, we inferred and isolated haplotype tracts of Native American, European, or African origin to perform genome-wide association studies. In the whole cohort, the rs887829 variant and others near UGT1A1 were the unique signals achieving genome-wide statistical significance (b = 0.30; p = 3.34 × 10−57). After applying deconvolution methods, we found that significance is also maintained in Native American (b = 0.35; p = 3.29 × 10−17) and European (b = 0.28; p = 1.14 × 10−23) ancestry components. The rs887829 variant explained a higher percentage of the variance of bilirubin in the Native American (37.6%) compared to European ancestry (28.4%). In Native American ancestry, carriers of the TT genotype of this variant averaged 4-fold higher bilirubinemia compared to the CC genotype (p = 2.82 × 10−12). We showed for the first time that UGT1A1 variants are the primary determinant of bilirubin levels in Native American ancestry, confirming its pan-ethnic relevance. Our study illustrates the general value of the local ancestry deconvolution approach to assessing isolated ancestry effects in admixed populations.
  • Thumbnail Image
    Item
    Preconceptional and maternal obesity : epidemiology and health consequences
    (2016) Poston, Lucilla; Caleyachetty, Rishi; Cnattingius, Sven; Corvalán, Camila; Uauy, Ricardo; Herring, Sharron; Gillman, Matthew W.
  • Thumbnail Image
    Item
    Structural responses to the obesity and non-communicable diseases epidemic : the chilean law of food labeling and advertising
    (2013) Uauy, Ricardo; Corvalán, Camila; Reyes, Marcela; Garmendia, María Luisa
  • Thumbnail Image
    Item
    Ultrasensitive estrogen levels at 7 years of age predict earlier thelarche : evidence from girls of the growth and obesity Chilean cohort
    (2015) Pereira, Ana; Corvalán, Camila; Uauy, Ricardo; Klein, Karen O.; Mericq, Verónica