**Early-Life Dietary Cadmium Exposure and Kidney Function in 9-Year-Old Children from the PROGRESS Cohort**

**Edna Rodríguez-López 1, Marcela Tamayo-Ortiz 1,2,\*, Ana Carolina Ariza 1, Eduardo Ortiz-Panozo 3, Andrea L. Deierlein 4, Ivan Pantic 5, Mari Cruz Tolentino 6, Guadalupe Estrada-Gutiérrez 7, Sandra Parra-Hernández 7, Aurora Espejel-Núñez 7, Martha María Téllez-Rojo 1, Robert O. Wright 8,9 and Alison P. Sanders 8,9,\***


Received: 21 August 2020; Accepted: 23 September 2020; Published: 7 October 2020

**Abstract:** Cadmium (Cd) is a toxic metal associated with adverse health e ffects, including kidney injury or disease. The aims of this study were to estimate dietary Cd exposure during childhood, and to evaluate the association of early-life dietary Cd with biomarkers of glomerular kidney function in 9-year-old Mexican children. Our study included 601 children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with up to five follow-up food frequency questionnaires from 1 to 9 years of age; and 480 children with measures of serum creatinine, cystatin C, and blood nitrogen urea (BUN), as well as 9-year-old estimated glomerular filtration rate. Dietary Cd was estimated through food composition tables. Multiple linear regression models were used to analyze the association between 1 and 9 years, cumulative dietary Cd, and each kidney parameter. Dietary Cd exposure increased with age and exceeded the tolerable weekly intake (TWI = 2.5 μg/kg body weight) by 16–64% at all ages. Early-life dietary Cd exposure was above the TWI and we observed inverse associations between dietary Cd exposure and kidney function parameters. Additional studies are needed to assess kidney function trajectories through adolescence. Identifying preventable risk factors including environmental exposures in early life can contribute to decreasing the incidence of adult kidney disease.

**Keywords:** cadmium; children; diet; kidney function
