Association between iron deficiency anemia and sleep duration in the first year of life

OBJECTIVE: The aim of this study was to investigate the association between iron deficiency anemia and sleep duration in the first year of life. METHODS: A total of 123 infants were investigated, with sleep being evaluated at 3, 6, and 12 months of age and anemia at birth and 6 months. The cutoff points for anemia and short sleep duration were hemoglobin <11 g/dL (at birth and/or 6 months) and <10 h (at 3, 6, and 12 months), respectively. The comparison of the average sleep time between infants with and without anemia was performed using the Student’s t-test, and logistic regression models were also used to verify differences in the sleep duration (short/not short) between the groups. Linear regression analyses were conducted to determine the association between sleep duration and hemoglobin values. The analyses were adjusted for potential confounders. RESULTS: Children with anemia were more likely to be short sleepers [odds ratio (95% confidence interval (CI)): 4.02 (1.02–15.76); p≤0.05], and for each unit increase in hemoglobin values, the sleep duration increased by 16.2 min [β (95%CI): 0.27 (0.00–0.55); p≤0.05), regardless of family income, maternal schooling, gender, and body mass index at birth. CONCLUSIONS: Our results suggest that iron deficiency anemia is associated with short sleep duration in the first year of life and indicate the need for longitudinal investigations, with longer follow-up, to verify the impact of anemia on sleep duration at subsequent ages.