Objectives: Osteogenesis imperfecta (OI) is a group of rare genetic disorders characterized by osteoporosis, predisposition to fracture, and scoliosis. Recently, however, there has been increased focus on pulmonary insufficiency, as it is the leading cause of mortality in individuals with OI. The primary objective of this study is to determine if reduced pulmonary function in individuals with OI is intrinsic to the underlying connective tissue disorder. Another goal of this study is to explore respiratory function and assess how it relates to type of OI, presence of scoliosis/chest wall deformity, and other factors such as age or co-existing co-morbidities.
Methods: This is a prospective pilot study of adults diagnosed with OI. Anteroposterior X-rays were evaluated for scoliosis (curve >10°). The largest curve was used for analysis. Pulmonary function (FEV1/FVC) was defined as restrictive disease >80%, and obstructive disease <70%. Chest CTs were qualitatively evaluated for evidence of lung disease. Echocardiograms and EKG were obtained to assess cardiac health. Bivariate correlation analyses (Spearmans rho correlation coefficient and point-biserial correlation analysis (P<0.05)) were performed.
Results: Twenty-six individuals with OI were enrolled (77% female, 23% male). Mean age was 39±15 years. 19% had type 3, 46% type 4, and 35% type 1. 57% had scoliosis, 14% had cardiac comorbidities, and 7% had pulmonary comorbidities. 90% of chest CTs revealed abnormalities (bronchial wall thickening, parenchymal scarring, ground-glass opacities, air trapping). 52% of EKGs showed abnormal results (tachycardia, non-specific wave abnormalities). 77% had trace mitral, tricuspid, or aortic regurgitation on echo. There was no correlation between curve magnitude and pulmonary function (R=0.136, P=0.509).
Conclusion: Pulmonary function is weakly correlated with curve magnitude, suggesting that decreased pulmonary function is likely due to intrinsic lung disease - not exclusively an effect of scoliosis. This mandates reassessment of clinical practice in evaluating cardiopulmonary health of these individuals. This study was made possible through the OI Foundations Jamie Kendall Fund for OI Adult Health.
Disclosure: Advisory Board or Panel. Alexion - Speakers Bureau. Ascendis - Advisory Board or Panel.