A 5-Year Follow-up Study Investigating Factors Associated With Osteoporotic Fracture in Chinese Postmenopausal Women
Condition: Osteoporotic Fractures; Osteoporosis, Postmenopausal
MeSH terms: Osteoporosis; Osteoporosis, Postmenopausal; Fractures, Bone; Osteoporotic Fractures
Study type: Interventional

Summary: 
      This proposed study was designed to investigate the prevalence of a 5-year incident
      osteoporotic fracture and evaluate the association of a 5-year change of 25-hydroxyvitamin D
      (25[OH]D)/bone turnover makers/bone mineral density (BMD) with the incident fracture in the
      Chinese postmenopausal women, based on an endeavor of a 5-year post-baseline follow-up visit
      of a previous cross-sectional study, PK-VF, in which 1724 participants were enrolled and
      examined.
    

Detailed description: 
      1. In 2013, 5 years after PK-VF, the same 2070 subjects were contacted by the original
           sites. Among them 1242 subjects were able to come for the follow-up assessment.

        2. Clinical assessments: The participant's bio-information, physical examination and
           medical history were collected;Questionnaire including social/life style and medical
           evaluations (years since menopause (YSM), fracture history, milk/yoghourt/coffee/wine
           intake, calcium intake, or smoking history) were collected by PK-VF investigators.
           Non-vertebral fracture history evaluation: specific non-vertebral fracture sites include
           rib or clavicle, forearm, upper arm, hand (including wrist), pelvis, hip, thigh (not
           including hip), leg, and foot (including ankle). When non-vertebral fractures are
           suspected, questions were raised to the participant to eliminate possible biases (How
           did you get these fractures, a slight fall at home, fell from a high place, hit by
           someone, broken during a car accident or an operation? Did you see a doctor to confirm
           these fractures?) A fracture occurred in regular daily activities or due to mild trauma
           was defined as fragile non-vertebral fracture.

        3. Biochemical measurements: Fasting blood sample (~5 ml) was collected from each
           participant at participating sites; In 2007-2008 study, blood samples were collected
           during April-July, while in the 5-year follow-up; samples were collected in the same
           period of time. C-terminal telopeptide of type I collagen (β-CTX), N-aminoterminal
           prepeptide of type I procollagen (P1NP), and 25 (OH) D will be determined by a
           laboratory method of electrochemiluminescence (E170; Roche Diagnostics, Basel,
           Switzerland) in the institute (Peking Union); Chemistry including alkaline phosphatase
           (ALP), calcium (Ca), creatinine (Cr), and glucose, will be measured by using automated
           techniques in the institute (Peking Union);

        4. BMD measurements: Lumbar spine (LS) and femoral neck (FN) BMDs by dual-energy x-ray
           absorptiometry (DXA) (Lunar or Norland) at PK-VF sites. BMD calibration: The
           participant's BMD were evaluated by the same type of DXA as previous. The coefficients
           of variation of the seven hospitals were 0.75% to 1.7% for LS and 0.56% to 1.0% for FN.
           Cross-calibration equations between machines are: LS BMD (g/cm^2) Lunar = 1.012 ×
           Norland + 0.0137 and, FN BMD (g/cm^2) Lunar = 1.0377 × Norland + 0.00026

        5. Vertebral fracture diagnosis: Lateral radiographs of the thoracolumbar spine (T4-L5)
           were taken at PK-VF sites. Vertebral fractures will be assessed using Genant's
           semi-quantitative visual criteria. Two specialist radiologists will independently
           evaluate and diagnose vertebral fracture. A worsened existing vertebral fracture will be
           regarded as a new vertebral fracture.

      In 2007-2008 study(Published article about this study could be found in Pubmed, PMID:
      24760246), 2070 participants were recruited in this cohort, and 837 subjects (40%) were
      diagnosed as osteoporosis. After 5 years, 1242 subjects agreed to be re-evaluated in 2013.
      Questionnaires and blood samples were collected, and BMD and spine x-ray were obtained at the
      5-year follow up. We estimate that around 625 subjects would be diagnosed as osteoporosis.
      The remaining works include blood sample test (25(OH)D, CTX and P1NP),spine x-ray films
      reading, data input and statistical analysis, paper writing and publication.
    

Intervention name(s): Questionaire survey; Bone mineral density examination; Vertebral fracture assessment; Biochemical markers analysis
Intervention type(s): Other; Radiation; Radiation; Other
Intervention description(s): We used a questionnaireto collect clinical data of the subjects. The questionnaire includes basic data, menstruation and pregnancy, habits and customs, daily activity, common healthy situation, history of drugs and history of factures.; We use dual energy X-ray absorptiometry (DXA) to exam the BMD at lumbar spine (L2-4, LS) and hip.; X-ray of thoracic and lumbar spine was taken, and the pictures were read by radiological specialists. The diagnosis of vertebral fracture was executed according to Genant's semiquantitative technique.; Fasting blood sample was collected for each subject. Common biochemical maerkers including serum calcium(Ca), serum phosphate(P), serum glucose(Glu), serum creatinine(Cr), alkaline phosphatase(ALP), alanine aminotransferase(ALT) were analyzed. Besides, we also detect bone speficific markers including 25-hydroxyl Vitamin D(25OHD), parathyroid hormone(PTH), β-isomerized C-terminal telopeptide of type I collagen(β-CTX), N-terminal procollagen of type 1 collagen(P1NP) and osteocalcin(OC).
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Screening
Keywords: bone mineral density; 25(OH)D