175 - Evolution of sleep disordered breathing in infants with achondroplasia

Poster Number: 175
Publication Number: 175.449

Janet M. Legare, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; David Ingram, Children's Mercy Hospitals and Clinics, Kansas City, MO, United States; Jacqueline T. Hecht, University of Texas McGovern Medical School, Bellaire, TX, United States; Richard M. Pauli, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Lorena Dujmusic, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Peggy Modaff, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Mary Ellen Little, NemoursAlfred I. duPont Hospital for Children, West Deptford, NJ, United States; Cory Smid, UW Health, Madison, WI, United States; David Felipe. Rodriguez-Buritica, McGovern Medical School at the University of Texas Health Science Center at Houston, Missouri City, TX, United States; Michael Bober, Nemours Children's Hospital, Wilmington, DE, United States; Julie Hoover-Fong, Johns Hopkins University, Baltimore, MD, United States; Syed Shahrukh Hashmi, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States

Background: Children with achondroplasia (ACH) are at risk for sudden death in infancy due to sleep disordered breathing (SDB) and foramen magnum stenosis (FMS). The AAP guidelines recommend polysomnogram (PSG) and neuroimaging in the first few months of life to help detect FMS.

Objective: To clarify the natural progression of PSG indices over the first two years in infants with ACH without surgery (surgically naive, SN), quantify differences in PSG between SN patients and those who went on to have surgery (i.e. adenoidectomy (AD) and cervicomedullary decompression (CMD)), and assess the differences in obstructive apnea hypopnea index (OAHI) and central apnea index (CAI) before and after these two surgical interventions.

Design/Methods: Data abstracted from 1374 patients evaluated over 6 decades at 4 skeletal dysplasia centers were entered into a REDCap database. Data analyzed included OAHI, CAI, total sleep time (TST), and included only studies with adequate information, performed in room air and with TST greater than 240 minutes. Statistical analyses used include linear mixed models (LMM), Kruskal-Wallis tests, and Fisher exact test.

Results: Four hundred eleven PSGs and 86 surgeries were performed in 163 patients in the first two years of life. 251 PSGs in 127 infants met inclusion criteria. In SN infants, median OAHI decreased from 6.9 in the first 6 months (m) to 1.3 between 13-18m, then increased to 9.4 by 19-24m. The median CAI stayed relatively low at 1.3 but there was more variability in the first 6m. There was no significant difference between age at first PSG or PSG indices for SN infants and patients who underwent AD or CMD. Post operative PSGs occurred at a median of 4.8m for OAHI analysis and 5.7m for CAI analysis. There was a significant decrease in OAHI after AD (-7.7 units, p< .001) but not after CMD (-5.6 units, p=0.18). Conversely, there was a significant decrease in CAI after CMD (-1.9 units, p=0.02) but not after AD (0.5 units, p=0.48).

Conclusion(s): This novel study shows the natural progression of SDB in infants with ACH. Without surgery, sleep indices improved over the first 12m of life in this cohort, but then OAHI increased by 2 years of age. Neither OAHI nor CAI differentiated those infants who subsequently underwent surgery suggesting other important clinical factors in the decision making process. Independent of age, AD is associated with improvement in OAHI and CMD with improvement in CAI. These historical cohort results provide important information that will be confirmed in ongoing ACH studies.