Child Hemoglobin Trajectories across the First 10 Years of Life and Association with Child Cognition and Academic Achievement at 10-11 Years.

BACKGROUND

Anemia is a global health concern, although the importance of changes in hemoglobin (Hb) and cognitive outcomes in childhood remains unclear.

OBJECTIVES

We examined the association between child Hb trajectories and anemia with cognitive development and academic achievement at 10-11 y.

METHODS

We used prospective data from Vietnamese children (n = 831) born to females who participated in a preconception micronutrient supplementation trial (PRECONCEPT). Hb was measured at 3 mo, 6 mo, 1 y, 2 y, and 10-11 y. Multivariable linear regression models assessed the association between Hb trajectories and anemia with cognitive development [full-scale intelligence quotient (FSIQ)], and academic achievement (mathematics and reading) at 10-11 y, adjusting for maternal (intervention, education, age, and mental health), child (age and sex), and household (home environment and socioeconomic status) characteristics.

RESULTS

Three child Hb trajectories were identified (low-6.4%, middle-52.2%, and high-41.4%). Compared with the middle and high trajectory groups, children in the low trajectory had the lowest Hb concentrations at 3 mo (Hb: 9.7 g/dL) and through age 10-11 y (11.2 g/dL). Children in the low-Hb trajectory had lower FSIQ (89.8 compared with 93.2), math (12.1 compared with 13.5), and reading (17.8 compared with 19.0) scores compared with the high Hb trajectory. These differences were attenuated in adjusted models. Children in the low and middle Hb trajectories had nonsignificantly lower FSIQ {-0.93 (95% confidence interval: -4.57, 2.71) and [-1.13 (-2.92, 0.66)]}, reading scores [-0.01 (-1.36, 1.34) and -0.46 (-1.13, 0.21)] and math scores [-0.57 (-1.15, 0.01) and -0.65 (-1.82, 0.51)]. Anemia status at 10-11 y was negatively associated with FSIQ [-3.82 (-6.68, -0.76)] and math scores [-1.04 (-2.03, -0.05)] in adjusted models.

CONCLUSIONS

Child Hb trajectories across the first 10 y of life were largely established early in life and had weak associations with cognition and academic achievement at 10-11 y. Anemia among 10-y-old children was associated with lower IQ and math scores, which underscores the importance of continued investment in nutrition programs among school-age children.