Airflow limitation as a risk factor for low bone mineral density and hip fracture

摘要

AimTo investigate whether airflow limitation is associated with bone mineral density (BMD) and risk of hip fractures.MethodsA community sample of 5,100 subjects 47–48 and 71–73 years old and living in Bergen was invited. Participants filled in questionnaires and performed a post-bronchodilator spirometry measuring forced expiratory volume in 1 second (FEV_(1)) and forced vital capacity (FVC). All attendants were invited to have a BMD measurement of the hip. During 10 years of follow-up, information on death was collected from the Norwegian Cause of Death Registry, and incident hip fractures were registered from regional hospital records of discharge diagnoses and surgical procedure codes.ResultsThe attendance rate was 69% (n =3,506). The prevalence of chronic obstructive pulmonary disease (COPD) (FEV_(1)/FVC0.7) was 9%. In multiple logistic regression, the lowest quartile of BMD versus the three upper was significantly predicted by FEV_(1)/FVC0.7 and FEV_(1)% predicted (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.11 to 2.25, and OR per increase of 10%: 0.92, 95% CI: 0.86 to 0.99, respectively). Hip fracture occurred in 126 (4%) participants. In a Cox regression analysis, FEV_(1)% predicted was associated with a lowered risk of hip fracture (hazard ratio per increase of 10%: 0.89, 95% CI: 0.79 to 0.997).ConclusionAirflow limitation is positively associated with low BMD and risk of hip fracture in middle-aged and elderly.