Browsing by Author "Blanco, Estela"

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    Association of fasting Orexin-A levels with energy intake at breakfast and subsequent snack in Chilean adolescents
    (2022) Rilling, Fabian Lanuza; Reyes, Marcela; Blanco, Estela; Burrows, Raquel; Peirano, Patricio; Algarin, Cecilia; Merono, Tomas; Gahagan, Sheila
    Orexin-A, a hormone secreted by orexin neurons, is involved in caloric-intake regulation. Current understanding is based primarily on animal studies. Studies of orexin in humans are scarce, and to our knowledge there are no prior studies in adolescents. We studied fasting Orexin-A levels related to energy intake at breakfast and a subsequent snack in adolescents (n = 668) from a longitudinal study in Chile. Body-Mass Index (BMI), components of the metabolic syndrome and fasting blood levels of leptin, insulin, ghrelin, and orexin-A were measured. Energy intake was calculated based on food weights before and after the standardized breakfast and subsequent snack. High energy intake was defined as = 75th percentile. We assessed the relationship between orexin-A and high energy intake, adjusting for confounders. Higher orexin levels were associated with high breakfast energy intake (OR: 1.21; 95%CI: 0.98-1.49). Conversely, those with higher orexin levels showed a non-significant trend for lower odds of high energy intake for the snack (OR: 0.87; 95%CI: 0.70-1.07). There was a significant interaction between high breakfast energy intake and orexin levels. Those who ate more calories at breakfast displayed a lower inhibitory effect of orexin on eating at the snack (p < 0.05). There was no significant interaction between weight status and orexin. In conclusion, orexin-A levels were associated with breakfast energy intake and inversely related with subsequent snack energy intake in participants whose caloric intake at breakfast was within the normal range. Based on these findings, it appears that the association of orexin-A with energy intake depends on eating behavior.
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    Genetic determinants of metabolic biomarkers and their associations with cardiometabolic traits in Hispanic/Latino adolescents
    (2022) Kim, Daeeun; Justice, Anne E.; Chittoor, Geetha; Blanco, Estela; Burrows, Raquel; Graff, Mariaelisa; Green Howard, Annie; Wang, Yujie; Rohde, Rebecca; Buchanan, Victoria L.; Voruganti, V. Saroja; Almeida, Marcio; Peralta, Juan; Lehman, Donna M.; Curran, Joanne E.; Comuzzie, Anthony G.; Duggirala, Ravindranath; Blangero, John; Albala, Cecilia; Santos Martín, José Luis; Angel, Bárbara; Lozoff, Betsy; Gahagan, Sheila; North, Kari E.
    Background: Metabolic regulation plays a significant role in energy homeostasis, and adolescence is a crucial life stage for the development of cardiometabolic disease (CMD). This study aims to investigate the genetic determinants of metabolic biomarkers—adiponectin, leptin, ghrelin, and orexin—and their associations with CMD risk factors. Methods: We characterized the genetic determinants of the biomarkers among Hispanic/Latino adolescents of the Santiago Longitudinal Study (SLS) and identified the cumulative effects of genetic variants on adiponectin and leptin using biomarker polygenic risk scores (PRS). We further investigated the direct and indirect effect of the biomarker PRS on downstream body fat percent (BF%) and glycemic traits using structural equation modeling. Results: We identified putatively novel genetic variants associated with the metabolic biomarkers. A substantial amount of biomarker variance was explained by SLS-specific PRS, and the prediction was improved by including the putatively novel loci. Fasting blood insulin and insulin resistance were associated with PRS for adiponectin, leptin, and ghrelin, and BF% was associated with PRS for adiponectin and leptin. We found evidence of substantial mediation of these associations by the biomarker levels. Conclusions: The genetic underpinnings of metabolic biomarkers can affect the early development of CMD, partly mediated by the biomarkers.
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    Genome-wide association study identifying novel variant for fasting insulin and allelic heterogeneity in known glycemic loci in Chilean adolescents: The Santiago Longitudinal Study
    (2020) Buchanan, Victoria L.; Wang, Yujie; Blanco, Estela; Graff, Mariaelisa; Albala, Cecilia; Burrows, Raquel; Santos Martín, José Luis; Angel, Bárbara; Lozoff, Betsy; Saroja Voruganti, Venkata; Guo, Xiuqing; taylor, Kent D.; Chen, Yii-Der Ida; Yao, Jie; Tan, Jingyi; Downie, Carolina; Highland, Heather M.; Justice, Anne E.; Gahagan, Sheila; North, Kari E.