title: Incidence of and risk factors for non-vertebral and vertebral fracture in female Chinese patients with systemic lupus erythematosus: a five-year cohort study.
abstract: OBJECTIVE
  The objective of this paper is to investigate the incidence of both non-vertebral and vertebral fracture in female patients with systemic lupus erythematosus (SLE) and to identify risk factors for incident fracture.
  
  
  METHODS
  In a five-year prospective study of 127 female Chinese SLE patients with an average age of 46.9 years (SD: 10.1 years), information on potential risk factors, including demographics, clinical data and bone mineral density (BMD) at lumbar spine and hip by dual-energy X-ray absorptiometry was collected at baseline. At follow-up, participants reported incident non-vertebral fracture during the study period. Semi-quantitative analysis was used to determine incident vertebral fracture on lateral thoracic and lumbar radiographs, defined as any vertebral body graded normal at baseline and at least mildly deformed (20%-25% reduction or more in any vertebral height) at follow-up.
  
  
  RESULTS
  Nine incident non-vertebral fractures occurred in eight patients during the study period. Six patients had one or more incident vertebral fractures. The incidence of non-vertebral and vertebral fracture was 1.26 and 0.94 per 100 patient-years, respectively. In multivariate logistic analyses, independent variables associated with incident non-vertebral fracture were duration of glucocorticoid use and prevalent lumbar spine osteoporosis, while risk factors associated with incident vertebral fracture were higher organ damage and prevalent lumbar spine osteoporosis.
  
  
  CONCLUSIONS
  The incidence of fracture in SLE patients is lower than the prevalence reported in cross-sectional studies. Lumbar spine BMD appears to have a stronger relationship with incident fracture than hip BMD. This warrants further investigation regarding the optimal site of BMD measurement when predicting fracture risk in SLE patients.
authors.affiliation: Department of Medicine and Therapeutics.
authors.forename: T Y
authors.initials: TY
authors.lastname: Zhu
authors.affiliation: Department of Imaging and Interventional Radiology.
authors.forename: J F
authors.initials: JF
authors.lastname: Griffith
authors.affiliation: The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: S-K
authors.initials: SK
authors.lastname: Au
authors.affiliation: Department of Medicine and Therapeutics.
authors.forename: X-L
authors.initials: XL
authors.lastname: Tang
authors.affiliation: The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: A W
authors.initials: AW
authors.lastname: Kwok
authors.affiliation: The Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: P-C
authors.initials: PC
authors.lastname: Leung
authors.affiliation: Department of Medicine and Therapeutics.
authors.forename: E K
authors.initials: EK
authors.lastname: Li
authors.affiliation: Department of Medicine and Therapeutics lstam@cuhk.edu.hk.
authors.forename: L-S
authors.initials: LS
authors.lastname: Tam
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015519:Bone Density; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000150:complications*; D008875:Middle Aged; D012307:Risk Factors; D016103:Spinal Fractures / Q000453:epidemiology / Q000209:etiology; D013997:Time Factors; D055815:Young Adult
keywords: Systemic lupus erythematosus; bone mineral density; fracture; vertebral fracture