The airway smooth muscle layer is structurally abnormal in low birth weight infants: implications for obstructive disease

This research letter concerns known associations between intrauterine growth restriction (IUGR), low birth weight (LBW) and increased risk of obstructive disease [1, 2]. Our prior animal simulations, specifically a mid-gestation maternal hypoxia mouse model of IUGR, has forwarded the hypothesis that increased risk of obstructive disease is due to abnormalities of the airway wall. In mice, IUGR causes airway smooth muscle (ASM) thickening of the fetus [3], and in postnatal life, increases airway wall stiffness [4] and modifies bronchoconstrictor response to inhaled methacholine [5]. These forerunner findings support airway pathophysiology ( i.e. , ASM) as a possible contributor to adverse respiratory function in growth restricted individuals born with LBW, a proposal that has not been tested in human subjects. Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article. Conflict of Interest: All other authors have nothing to disclose.