Preventing early, prolonged vitamin E deficiency: an opportunity for better cognitive outcomes via early diagnosis through neonatal screening.

Objective: To evaluate whether early diagnosis of cystic fibrosis (CF) through newborn screening (NBS) and early vitamin E status are associated with cognitive function.

Study Design: We assessed cognitive function for 71 children without meconium ileus (ages 7.3-16.9 years) enrolled in the screened (S) or control (C) group of the Wisconsin CF Neonatal Screening Project. The Test of Cognitive Skills, 2nd edition generated the cognitive skills index (CSI; mean = 100, SD = 16). Vitamin E deficiency at diagnosis was defined as plasma alpha-tocopherol (alpha-T) below 300 microg/dL (<300E). Primary analyses evaluated CSI scores across the 4 levels of group (S or C) by using alpha-T status (<300E or >300E) with analysis of covariance.

Results: After adjusting for covariates, CSI in the C<300E group was significantly lower than each of the other groups (C>300E, S<300E, and S>300E; P < .05). The highest proportion of CSI scores >84 occurred in the C<300E group (41%). Patients in this group also had the lowest mean head circumference z-scores at diagnosis.

Conclusions: Our results show that prolonged alpha-T deficiency in infancy is associated with lower subsequent cognitive performance. Thus, diagnosis via NBS may benefit the cognitive development of children with CF, particularly in those prone to vitamin E deficiency during infancy.