Browsing by Author "Tiller, Christina J."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Exhaled nitric oxide during infancy as a risk factor for asthma and airway hyperreactivity
    (European Respiratory Society, 2015-01) Chang, Daniel; Yao, Weiguo; Tiller, Christina J.; Kisling, Jeffrey; Slaven, James E.; Yu, Zhangsheng; Kaplan, Mark H.; Tepper, Robert S.; Department of Pediatrics, IU School of Medicine
    Childhood asthma is often characterised by elevated exhaled nitric oxide (eNO), decreased lung function, increased airway reactivity and atopy; however, our understanding of when these phenotypic airway characteristics develop remains unclear. This study evaluated whether eNO, lung function, airway reactivity and immune characteristics during infancy are risk factors of asthma at age 5 years. Infants with eczema, enrolled prior to wheezy illness (n=116), had eNO, spirometry, airway reactivity and allergen sensitisation assessed at entry to the study and repeated at age 5 years (n=90). Increasing eNO at entry was associated with an increased risk of asthma (p=0.037) and increasing airway reactivity (p=0.015) at age 5 years. Children with asthma at 5 years of age had a greater increase in eNO between infancy and age 5 years compared with those without asthma (p=0.002). Egg sensitisation at entry was also associated with an increased risk of asthma (p=0.020), increasing eNO (p = 0.002) and lower forced expiratory flows (p=0.029) as a 5 year-old. Our findings suggest that, among infants at high risk for developing asthma, eNO early in life may provide important insights into the subsequent risk of asthma and its airway characteristics.
  • Thumbnail Image
    Item
    Membrane and Capillary Components of Lung Diffusion in Infants with Bronchopulmonary Dysplasia
    (American Thoracic Society, 2016-04-01) Chang, Daniel V.; Assaf, Santiago J.; Tiller, Christina J.; Kisling, Jeffrey A.; Tepper, Robert S.; Pediatrics, School of Medicine
    RATIONALE: Autopsied lungs of infants with bronchopulmonary dysplasia (BPD) demonstrate impaired alveolar development with larger and fewer alveoli, which is consistent with our previous physiologic findings of lower pulmonary diffusing capacity of the lung for carbon monoxide (DL(CO)) in infants and toddlers with BPD compared with healthy controls born at full term (FT). However, it is not known whether the decreased DL(CO) in infants with BPD results from a reduction in both components of DL(CO): pulmonary membrane diffusing capacity (D(M)) and Vc. OBJECTIVES: We hypothesized that impairment of alveolar development in BPD results in a decrease in both D(M) and Vc components of DlCO but that the D(M)/Vc ratio would not differ between the BPD and FT groups. METHODS: DL(CO) was measured under conditions of room air and high inspired oxygen (90%), which enabled D(M) and Vc to be calculated. MEASUREMENTS AND MAIN RESULTS: D(M) and Vc increased with increasing body length; however, infants with BPD had significantly lower D(M) and Vc than FT subjects after adjustment for race, sex, body length, and corrected age. In contrast to D(M) and Vc, the D(M)/Vc ratio remained constant with increasing body length and did not differ for infants with BPD and FT subjects. CONCLUSIONS: Our findings are consistent with infants with BPD having impaired alveolar development with fewer but larger alveoli, as well as a reduced Vc.
  • Thumbnail Image
    Item
    Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function (VCSIP): Rationale, design, and methods of a randomized, controlled trial of vitamin C supplementation in pregnancy for the primary prevention of effects of in utero tobacco smoke exposure on infant lung function and respiratory health
    (Elsevier, 2017-07) McEvoy, Cindy T.; Milner, Kristin F.; Scherman, Ashley J.; Schilling, Diane G.; Tiller, Christina J.; Vuylsteke, Brittany; Shorey-Kendrick, Lyndsey E.; Spindel, Eliot R.; Schuff, Robert; Mitchell, Julie; Peters, Dawn; Haas, David; Jackson, Keith; Tepper, Robert S.; Morris, Cynthia D.; Department of Obstetrics and Gynecology, IU School of Medicine
    Despite strong anti-smoking efforts, at least 12% of American women cannot quit smoking when pregnant resulting in > 450,000 smoke-exposed infants born yearly. Smoking during pregnancy is the largest preventable cause of childhood respiratory illness including wheezing and asthma. Recent studies have shown a protective effect of vitamin C supplementation on the lung function of offspring exposed to in utero smoke in a non-human primate model and an initial human trial. Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function (VCSIP) is a randomized, double-blind, placebo-controlled trial to evaluate pulmonary function at 3 months of age in infants delivered to pregnant smokers randomized to 500 mg/day of vitamin C versus placebo during pregnancy. Secondary aims evaluate the incidence of wheezing through 12 months and pulmonary function testing at 12 months of age. Women are randomized between 13 and 23 weeks gestation from clinical sites in Portland, Oregon at Oregon Health & Science University and PeaceHealth Southwest Medical Center and in Indianapolis, Indiana at Indiana University and Wishard Hospital. Vitamin C supplementation occurs from randomization to delivery. Monthly contact with participants and monitoring of medical records is performed to document medication adherence, changes in smoking and medical history, and adverse events. Pulmonary function testing of offspring occurs at 3 and 12 months of age and incidence of wheezing and respiratory illness through 12 months is captured via at least quarterly questionnaires. Ancillary studies are investigating the impact of vitamin C on placental blood flow and DNA methylation.