The Santiago Longitudinal Study (SLS) is a longitudinal prospective cohort study of 1,790 infants originally enrolled in a double-blind randomized control trial to prevent iron-deficiency anemia (R01-HD-033487, PI: B. Lozoff). Healthy infants were recruited from community clinics in low-to middle-income neighborhoods in Santiago, Chile (1991-1996). Non-anemic infants were randomly assigned to receive either an iron-fortified formula, a low-iron formula, or a no-added iron condition. The preventive trial assessed the effectiveness of the various conditions for preventing iron-deficiency anemia. Infants were subsequently studied at ages 5, 10, and 21 years and 3 times during adolescence, the latter funded by a NIDA drug study (R01-DA-097295; PI: J. Delva).

A NHLBI grant (R01-HL-088530; PI: S. Gahagan) provided resources to study the cardiovascular health, diet, physical activity, and growth of 679 of the original cohort participants at 16 years and 1,040 cohort participants at 23 years of age. This project aims to understand the biopsychosocial determinants of the development of obesity and cardiometabolic risks at adolescence and young adulthood. At each age, numerous cardiometabolic risks and biomarkers were collected, including fasting serum glucose, cholesterol, triglycerides, lipids, inflammation markers, blood pressure, anthropometric measurements, body mass index (BMI), overweight/obesity, dual-energy X-ray absorptiometry (DEXA scans), and, on a select subset, liver ultrasounds. The SLS is the only Hispanic/Latino cohort of which we are aware that contains longitudinal data on cardiovascular health metrics from infancy to adulthood, including diet, physical activity, smoking/smoking exposure, body mass, blood pressure, cholesterol, and fasting blood glucose.

In addition, the Santiago Longitudinal Study (SLS) provides a wealth of data on infant, child, adolescent and young adult development. The study involved multiple measures assessing participants’ hematology, cognition, neurocognition, psychosocial adjustment, motor function, academic achievement, as well as numerous assessments related to maternal health, breastfeeding, socioeconomic status, parenting, family environment, and substance use. These data have provided research training to developmental-behavioral pediatric fellows, international research fellows, post-doctoral fellows, and numerous medical, graduate, and undergraduate students. The primary research team involves researchers at the University of California, San Diego and the University of Chile, Institute of Nutrition and Food Technology. However, strong collaborative ties exist with researchers worldwide, including at the University of North Carolina, Chapel Hill, the University of Michigan, Boston University, UC San Francisco, University of Denver, University of Minnesota, Geisinger Medical Center, and the Universidad del Desarrollo in Santiago, Chile, among others.

Data from the SLS have been used to address numerous issues related to obesity, cardiometabolic risks, and children’s and adolescents’ mental health. Some of the most recent publications are listed here.

Blanco E, Burrows R, Reyes M, Lozoff B, Gahagan S, Albala C. Breastfeeding as the sole source of milk for 6 months and adolescent bone mineral density. Osteoporos Int. 2017. Oct;28(19): 2823-2830.

Blanco E, Reyes M, Burrows R, Gahagan S. Eating in the absence of hunger and obesity among adolescents in Santiago, Chile. J Community Health. 2019 Oct 15;44(5):874-80.

Blanco E, Reyes M, Burrows RA, Martinez SM, Gahagan S. Low bone mineral density in a cohort of normal, overweight and obese Chilean adolescents. J Clinical Nursing. 2011 Dec;20(23‐24):3577-9.

Bradfield JP, Vogelezang S, Felix JF, . . . Justice AE, Gahagan S, Blanco E . . . Thiering E. A trans-ancestral meta-analysis of genome-wide association studies reveals loci associated with childhood obesity. Human Molecular Genetics. 2019 Oct 1;28(19):3327-38.

Burrows R, Correa-Burrows P, Reyes M, Blanco E, Albala C, Gahagan S. Low muscle mass is associated with cardiometabolic risk regardless of nutritional status in adolescents: A cross-sectional study in a Chilean birth cohort. Pediatric Diabetes. 2017;18:895-902.

Burrows R, Correa-Burrows P, Rogan J, Cheng E, Blanco E, Gahagan S. (2019). Long-term vs. recent-onset obesity: Their contribution to cardiometabolic risk in adolescence. Pediatric Research, Aug 19. doi: 10.1038/s41390-019-0543-0.

Burrows R, Correa P, Rogan J, Bunout D, Barrera G, Blanco E, Kim E, Gahagan S. Obesity relates to the impairment of pancreatic β-cell function in early adulthood, independent of age at obesity onset: Findings from the Santiago Longitudinal Study. Diabetes Metab Res Rev. 2020.

Burrows R, Correa-Burrows P, Reyes M, Blanco E, Albala C, Gahagan S. Healthy Chilean adolescents with HOMA-IR≥ 2.6 have increased cardiometabolic risk: Association with genetic, biological, and environmental factors. J Diabetes Research. 2015.

Burrows RA, Leiva LB, Weisstaub G, Lera LM, Albala CB, Blanco E, Gahagan S. High HOMA‐IR, adjusted for puberty, relates to the metabolic syndrome in overweight and obese Chilean youths. Pediatric Diabetes. 2011 May;12(3pt2):212-8.

Cheng E, Burrows R, Correa P, Güichapani CG, Blanco E, Gahagan S. Light smoking is associated with metabolic syndrome risk factors in Chilean young adults. Acta diabetologica. 2019 Apr 8;56(4):473-9.

Cheng, J., East, P., Blanco, E., Kang-Sim, E., Castillo, M., Lozoff, B., & Gahagan, S. (2016). Obesity leads to declines in motor skills across childhood: A longitudinal cross-lagged analysis of children’s weight and motor proficiency. Child: Care, Health and Devel, 2016. 42 (3), 343-350.

Correa-Burrows P, Blanco E, Reyes M, Castillo M, Peirano P, Algarín C, Lozoff B, Gahagan S, Burrows R. Leptin status in adolescence is associated with academic performance in high school: A cross-sectional study in a Chilean birth cohort. BMJ Open. 2016 Oct 1;6(10):e010972.

Delker, E., East, P., Blanco, E., Wu, V., Encina, P., Lozoff, B., Delva, J., & Gahagan (2020). Associations among household chaos, school belonging and risk behaviors in adolescents. Journal of Primary Prevention.

Doom JR, Gahagan S, Caballero G, Encina P, Lozoff B. Infant iron deficiency, iron supplementation, and psychosocial stress as predictors of neurocognitive development in Chilean adolescents. Nutritional Neuroscience. 2019 Aug 6:1-0.

Doom, J. R., Gahagan, S., East, P. L., Encina, P., Delva, J. & Lozoff, B. (2020). Adolescent internalizing,
externalizing, and social problems following iron deficiency at 12-18 Months: The role of maternal
responsiveness. Child Development, 91(3), e545-e562.

Doom JR, Mason SM, Suglia SF, Clark CJ. Pathways between childhood/adolescent adversity, adolescent socioeconomic status, and long-term cardiovascular disease risk in young adulthood. Social Science & Medicine 2017;188:166-175

Doom JR, Reid BM, Blanco E, Burrows R, Lozoff B, Gahagan S. Infant psychosocial environment predicts adolescent cardiometabolic risk: A prospective study. J Pediatrics. 2019 Jun 1;209:85-91.

Doom JR, Richards B, Caballero G, Delva J, Gahagan S, Lozoff B. Infant iron deficiency and iron supplementation predict adolescent internalizing, externalizing, and social problems. Journal of Pediatrics. 2018 Apr 1;195:199-205.

Doom, J.R., Rivera, K.M., Blanco, E., Burrows, R., Correa-Burrows, P., East, P.L., Lozoff, B., & Gahagan, S. Sensitive periods for psychosocial risk in childhood and adolescence and cardiometabolic outcomes in young adulthood. Development and Psychopathology. 2020.

East, P., Blanco, E., Delker, E., Encina, P., Lozoff, B., & Gahagan, S. (2019). Effects of infant iron
deficiency on children’s cognitive outcomes: The roles of child affect and parent unresponsiveness.
Maternal and Child Health Journal, 23, 1240-1250.

East P, Doom J, Blanco E, Burrows R, Lozoff B, & Gahagan S. (2020). Young adult outcomes associated with lower cognitive functioning in childhood related to iron-fortified formula in infancy. Nutritional Neuroscience.

East P, Doom J, Delker E, Blanco E, Burrows R, Correa-Burrows P, Lozoff B, Gahagan S. Childhood socioeconomic hardship, family conflict, and young adult hypertension: The Santiago Longitudinal Study.
Social Science and Medicine. Apr 1, 2020; 253.

East P, Delker E, Blanco E, Burrows R, Lozoff B, Gahagan S. Home and family environment related to development of obesity: A 21-year longitudinal study. Childhood Obesity. 2019 Apr 1;15(3):156-66.

East P, Delker E, Blanco E, Lozoff B, Correa P, Burrows R, Gahagan S. BMI trajectories from birth to 23 years by cardiometabolic risks in young adulthood. Obesity. 2020 Apr;28(4):813-21.

East, P., Delker, E., Lozoff, B., Delva, Castillo, M, Gahagan, S. (2018). Associations among infant iron
deficiency, childhood emotion and attention regulation, and adolescent problem behaviors.
Child Development, 89(2), 593-608.

East, P., Lozoff, B., Blanco, E., Delker, E., Delva, J., Encina, P., & Gahagan, S. (2017). Infant iron
deficiency, child affect, and maternal unresponsiveness: Testing the long-term effects of functional
isolation. Developmental Psychology, 53(12), 2233-44.

Flannagan KS, Gahagan S, Das AK, Burrows RA, Lozoff B, Villamor E. Serum polyunsaturated fatty acids in middle childhood and body mass index change through adolescence. Annals of Nutrition and Metabolism. 2019;75(1):77-85.

Gahagan S, Delker E, Blanco E, Burrows R, Lozoff B. Randomized controlled trial of iron-fortified versus low-iron infant formula: developmental outcomes at 16 years. The Journal of Pediatrics. 2019 Sep 1;212:124-30.

Ibacahe, C., Correa-Burrows, P., Burrows, R., Barrera, G., Kim, E., Hirsch, S., … & Bunout, D. (2020). Accuracy of a Semi-Quantitative Ultrasound Method to Determine Liver Fat Infiltration in Early Adulthood. Diagnostics, 10(6), 431.

Justice AE, Chittoor G, Blanco E, Graff M, Wang Y, Albala C, Santos JL, Angel B, Lozoff B, Voruganti VS, North KE, Gahagan S. Genetic determinants of BMI from early childhood to adolescence: The Santiago Longitudinal Study. Pediatric Obesity. 2019 Mar;14(3):e12479.

Khuc K, Blanco E, Burrows R, Reyes M, Castillo M, Lozoff B, Gahagan S. Adolescent metabolic syndrome risk is increased with higher infancy weight gain and decreased with longer breast feeding. Int J Pediatrics. 2012 Jul 5;2012.

LaSpada, N., Delker, E., East, P., Blanco, E., Delva, J., Burrows, R., Lozoff, B., & Gahagan, S. Risk taking, sensation seeking and personality as related to changes in substance use from adolescence to young adulthood. J Adolescence. 2020;82: 23-31.

Lee J, East P, Blanco E, Kang-Sim E, Castillo M, Lozoff B, & Gahagan S. Early parenthood linked to new onset overweight/obesity among Chilean adolescents. Int J Adol Med & Health, 2016;28(2):225-227.

Madewell ZJ, Blanco E, Burrows R, Lozoff B, Gahagan S. Changes in socio-economic status and lipoproteins in Chilean adolescents: A 16-year longitudinal study. Public Health Nutrition. 2019 Feb;22(2):344-53.

Martinez SM, Blanco E, Burrows R, Lozoff B, Gahagan S. Mechanisms linking childhood weight status to metabolic risk in adolescence. Pediatric Diabetes. 2019 Dec 29.

Martinez SM, Blanco E, Gahagan S. (2014). Perception of neighborhood crime and drugs increases cardiometabolic risk in Chilean adolescents J Adol Health, 2014 Jun;54(6):718-23.

Nelson, T., East, P., Delva, J., Lozoff, B., & Gahagan, S. (2019). Children’s inattention and hyperactivity,
Mothers’ parenting, and risk behaviors in adolescence: A 10-year longitudinal study of Chilean children.
Journal of Developmental and Behavioral Pediatrics, 40 (4), 249-256.

Pacheco LS, Blanco E, Burrows R, Reyes M, Lozoff B, Gahagan S. Early onset obesity and risk of metabolic syndrome among Chilean adolescents. Preventing Chronic Disease. 2017;14.

Rana, M., Delker, E., East, P., Blanco, E., Burrows, R., Lozoff, B., & Gahagan, S. (2020). Mother-adolescent discrepancies in ratings of adolescents’ adjustment: Associations with maternal mental health and family factors. Journal of Developmental and Behavioral Pediatrics.

Reid BM, Doom JR, Argote RB, Correa-Burrows P, Lozoff B, Blanco E, Gahagan S. Pathways to inflammation in adolescence through early adversity, childhood depressive symptoms, and body mass index:
A prospective longitudinal study of Chilean infants. Brain, Behavior, and Immunity. 2019 Jun 8.

Reyes M, Burrows R, Blanco E, Lozoff B, Gahagan S. Greater early weight gain and shorter breastfeeding are associated with low adolescent adiponectin levels. Pediatric Obesity. 2018 May;13(5):277-84.

Reyes M, Hoyos V, Martinez SM, Lozoff B, Castillo M, Burrows R, Blanco E, Gahagan S. Satiety responsiveness and eating behavior among Chilean adolescents and the role of breastfeeding. Int J Obesity. 2014 Apr;38(4):552-7.

Reyes M, Quintanilla C, Burrows R, Blanco E, Cifuentes M, Gahagan S. Obesity is associated with acute inflammation in a sample of adolescents. Pediatric Diabetes, 2015 Mar;16(2):109-16.
Sanhueza GE, Delva J, Bares CB, Grogan-Kaylor A. Alcohol consumption among Chilean adolescents: Examining individual, peer, parenting and environmental factors. Int J Alcohol and Drug Research. 2013 Jan 1;2(1):89.

Suarez-Ortegon MF, Blanco E, McLachlan S, Fernandez-Real JM, Burrows R, Wild SH, Lozoff B, Gahagan S. Ferritin levels throughout childhood and metabolic syndrome in adolescent stage. Nutrition, Metabolism and Cardiovascular Diseases. 2019 Mar 1;29(3):268-78.

Van Holle, A., North, K., Gahagan, S., Blanco, E., Graff, M., et al. (2020). Sociodemographic predictors of early postnatal growth: Evidence from a Chilean infancy cohort. BMJ Open, 10, e033695.

Vasconcelos, M., East, P. Blanco, E., Lukacz, E., Caballero, G., Lozoff, B., & Gahagan, S. (2017). Early behavioral risks of childhood and adolescent daytime urinary incontinence and nocturnal enuresis. Journal of Developmental & Behavioral Pediatrics, 38(9),736-742

Vasquez F, Correa-Burrows P, Blanco E, Gahagan S, Burrows R. A waist-to-height ratio of 0.54 is a good predictor of metabolic syndrome in 16-year-old male and female adolescents. Pediatric Research 2019; 85(3): 269–274.

Wang H, Blanco E, Algarín C, Peirano P, Burrows R, Reyes M, Wing D, Godino JG, Gahagan S. Weight status and physical activity: Combined influence on cardiometabolic risk factors among adolescents, Santiago, Chile. Global Pediatric Health. 2016 Oct 19;3:2333794X16674561.

Wu, V., East, P., Delker, E., Blanco, E., Caballero, G., Delva, J., Lozoff, B., & Gahagan, S. (2019).
Associations among mothers’ depression, emotional and learning material support to their child, and
children’s cognitive functioning: A 16-year longitudinal study. Child Development. 90 (6), 1952-1968.