Associations of α- and γ-tocopherol during early life with lung function in childhood.
BACKGROUND
Tocopherol isoforms may regulate child lung growth and spirometric measures.


OBJECTIVE
Our aim was to determine the extent to which plasma α-tocopherol (α-T) or γ-tocopherol (γ-T) isoform levels in early childhood or in utero are associated with childhood lung function.


METHODS
We included 622 participants in the Project Viva cohort who had lung function at a mid-childhood visit (age 6-10 years). Maternal and child tocopherol isoform levels were measured by HPLC at the second trimester and 3 years of age, respectively. Multivariable linear regression models (adjusted for mid-childhood body mass index z scores, maternal education, smoking in pregnancy, and prenatal particulate matter with diameter of <2.5 micrometers (PM2.5) particulate exposure) stratified by tertiles of child γ-T level were used to assess the association of α-T levels with FEV1 and forced vital capacity (FVC) percent predicted. Similarly, models stratified by child α-T tertile evaluated associations of γ-T levels with lung function. We performed similar analyses with maternal second trimester tocopherol isoform levels.


RESULTS
The median maternal second trimester α-T level was 63 μM (interquartile range = 47-82). The median early-childhood level was 25 μM (interquartile range = 20-33 μM). In the lowest tertile of early-childhood γ-T, children with a higher α-T level (per 10 μM) had a higher mid-childhood FEV1 percent predicted (β = 3.09; 95% CI = 0.58-5.59 and a higher FVC percent predicted (β = 2.77; 95% CI = 0.47-5.06). This protective association of α-T was lost at higher γ-T levels. We did not see any consistent associations of second trimester levels of either α-T or γ-T with mid-childhood FEV1 or FVC.


CONCLUSION
When γ-T levels were in the lowest tertile, a higher early-childhood α-T level was associated with better lung function at mid-childhood. Second trimester maternal plasma α-T concentration was 3-fold higher than in the adult nonpregnant female population.
['Kumar|Rajesh|R|', 'Ferrie|Ryan P|RP|', 'Balmert|Lauren C|LC|', 'Kienzl|Matthew|M|', 'Rifas-Shiman|Sheryl L|SL|', 'Gold|Diane R|DR|', 'Sordillo|Joanne E|JE|', 'Kleinman|Ken|K|', 'Camargo|Carlos A|CA|', 'Litonjua|Augusto A|AA|', 'Oken|Emily|E|', 'Cook-Mills|Joan M|JM|']
D000328:Adult D002648:Child D005260:Female D006801:Humans D008168:Lung D008297:Male D011247:Pregnancy D011262:Pregnancy Trimester, Second D011297:Prenatal Exposure Delayed Effects D012129:Respiratory Function Tests D024502:alpha-Tocopherol D024504:gamma-Tocopherol
lung function Tocopherol isoforms child