Introduction: Premature birth (<37 weeks of gestation age, GA) occurs during a critical phase of skeletal muscle development and may induce permanent alterations in the structure and function of this organ system. We have shown that young adults born <29 weeks of GA have reduced aerobic capacity, which is dependent on the integrity of the skeletal muscles. Thus, we postulate that young adults born very prematurely (PT) have impaired skeletal muscle function compared to young adults born at term (T).
Methods: This prospective observational cohort included PT (<29 GA) and T controls aged 18 to 29 years. Muscle strength was characterized by grip strength (Linear Dynamometer, MedUp, Atlas Medic) and vertical jump. Muscle oxygenation was measured continuously by near-infrared spectroscopy (NIRS - Oxymon pro, Artinis medical) on the vastus lateralis and gastrocnemius during a cardiopulmonary exercise test. Between-group comparisons were performed by the Mann-Whitney U-test for non-parametric data and are presented as median (IQR).
Results: 16 young PT adults and 35 T controls were included in the study. There was no difference in grip strength (PT: 56kg (51 – 75); T: 62kg (53 – 82), p = 0.46). Performance on the vertical jump was significantly reduced in PT versus T (PT: 22cm (14 – 27); T: 27cm (22 – 39), p = 0.02). Using NIRS, we did not detect any differences in the relative change in oxygenated, deoxygenated and total hemoglobin in both muscles.
Conclusion: Although premature birth appears to affect the integrity of the skeletal muscle, we did not find between-group differences in its oxygenation during exercise in this small sample of PT and T born adults.
Camille Bastien Tardif– Master Student in physical activity sciences, University of Montréal
Camille Girard-Bock– PhD Candidate, University of Montréal
Anik Cloutier– Research Associate, CHU Sainte-Justine research center
Mathieu Dehaes– Assistant Professor, Department of Radiology and Institut de génie biomédical, Université de Montréal
Thuy Mai Luu– Clinician-scientist and Pediatrician, CHU Sainte-Justine
Anne Monique Nuyt– Full Time Professor, Department of Pediatrics, and neonatologist, CHU Sainte-Justine