Thoracic Kyphosis on Chest CT Scans Is Associated With Incident Vertebral Fractures in Smokers

Mayke J. van Dort*, Johanna H. M. Driessen, Elisabeth A. P. M. Romme, Piet Geusens, Paul C. Willems, Frank W. J. M. Smeenk, Emiel F. M. Wouters, Joop P. W. van den Bergh

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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 T-4 and below T-9 or T-12. 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 T-4 to T-12 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 T-4 to T-12 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. (c) 2019 American Society for Bone and Mineral Research.

Original languageEnglish
Pages (from-to)859-866
Number of pages8
JournalJournal of Bone and Mineral Research
Volume34
Issue number5
DOIs
Publication statusPublished - May 2019

Keywords

  • FRACTURE RISK ASSESSMENT
  • BIOMECHANICS
  • SCREENING
  • KYPHOSIS ANGLE
  • SMOKERS
  • OBSTRUCTIVE PULMONARY-DISEASE
  • BONE-DENSITY
  • OSTEOPOROTIC FRACTURES
  • HYPERKYPHOTIC POSTURE
  • GLOBAL BURDEN
  • COPD PATIENTS
  • RISK-FACTORS
  • WOMEN
  • PREVALENCE
  • MEN

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