Vehmeijer FOL, Santos S, de Rijke YB, et al. - The study was carried out to investigate the relationships between hair cortisol concentrations at 6 years and cardio-metabolic risk factors at 6 and 10 years. Cortisol concentrations were measured in the hair of 6-year-old children (n = 2,598) who took part in the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. At 6 or 10 years, hair cortisol concentrations were not independent of BMI, which was associated with cardiometabolic risk factors. The links between biological stress and cardiometabolic risk factors may emerge later in life.