Thoracic Kyphosis on Chest CT Scans Is Associated With Incident Vertebral Fractures in Smokers. (27th February 2019)

• Record Type: Journal Article
• Authors: van Dort, Mayke J; Driessen, Johanna HM; Romme, Elisabeth APM; Geusens, Piet; Willems, Paul C; Smeenk, Frank WJM; Wouters, Emiel FM; van den Bergh, Joop PW
• Is Part Of: Journal of bone and mineral research. Volume 34:Number 5(2019)
• Page Start: 859
• Page End: 866
• Publication Date: 2019-02-27
• Subjects: FRACTURE RISK ASSESSMENT -- BIOMECHANICS -- SCREENING -- KYPHOSIS ANGLE -- SMOKERS; Bones -- Metabolism -- Periodicals; Mineral metabolism -- Periodicals; 612.392
• DOI: 10.1002/jbmr.3672
• Languages: English
• ISSNs: 0884-0431

Abstract

ABSTRACT: Greater kyphosis angles lead to increased loading on vertebral bodies in computational models. However, results about the relationship between severity of kyphosis and incident vertebral fracture (VF) risk have been conflicting. Therefore, the aim of this study was to evaluate associations between 1) prevalent VFs and severity of kyphosis, and 2) severity of kyphosis and incident VF risk in smokers with or without chronic obstructive pulmonary disease (COPD). Former and current smokers with or without COPD were included. CT scans were made at baseline, 1‐year, and 3‐year follow‐up. VFs were evaluated on superposed sagittal CT reconstructions. Kyphosis was measured as the angle between the lines above T4 and below T9 or T12 . We included 1239 subjects (mean age 61.3 ± 8.0 years, 61.1% male, 80.6% with COPD), of whom 253 (20.4%) had a prevalent VF and 294 (23.7%) an incident VF within 3 years. Presence, number, and severity of prevalent VFs were associated with a greater kyphosis angle. The mean increase in kyphosis angle within 3 years was small but significantly greater in subjects with incident VFs compared with those without (2.2 ± 4.1 versus 1.2 ± 3.9 degrees, respectively, for T4 to T12 angle, p < 0.001). After adjustment for bone attenuation (BA) and prevalent VFs, baseline kyphosis angle was associated with incident VFs within 1 and 3 years (angle T4 to T12 per +1 SD, hazard ratio [HR] = 1.34 [1.12–1.61] and HR 1.29 [1.15–1.45], respectively). Our data showed that a greater kyphosis angle at baseline was independently associated with increased risk of incident VFs within 1 and 3 years, supporting the theory that greater kyphosis angle contributes to higher biomechanical loads in the spine. © 2019 American Society for Bone and Mineral Research.