Table 4 Univariable regression analysis of ΔBMD after 1 year of follow-up, in tertiles with high, low and no BMD loss, in the spine and the hip (dependent variables) and disease and demographic variables (independent variables)
RR (95% CI)High BMD lossLow BMD lossNo BMD loss
Age, years†1.02 (1.01 to 1.03)1.00 (0.99 to 1.01)1
Male*1.64 (1.08 to 2.53)1.55 (1.03 to 2.46)1
Postmenopausal women*1.44 (1.22 to 1.57)1.18 (0.90 to 1.40)1
Current smokers†1.13 (0.78 to 1.50)1.39 (1.01 to 1.75)1
BMI, kg/m2*0.99 (0.96 to 1.02)1.01 (0.97 to 1.04)1
SHS baseline†1.03 (1.01 to 1.05)0.99 (0.98 to 1.02)1
SHS progression >SDC*1.99 (1.13 to 3.84)2.41 (1.19 to 4.40)1
DAS baseline*1.01 (0.86 to 1.17)1.02 (0.87 to 1.18)1
ΔDAS after 6 months*1.16 (0.92 to 1.47)1.06 (0.84 to 1.34)1
HAQ baseline*1.17 (0.97 to 1.36)1.07 (0.87 to 1.27)1
ΔHAQ after 6 months*1.03 (0.69 to 1.54)1.31 (0.86 to 1.98)1
Positive RF*1.03 (0.82 to 1.20)0.96 (0.75 to 1.15)1
Bisphosphonate users*0.34 (0.13 to 0.77)0.44 (0.20 to 0.93)1
Vitamin D and/or calcium supplement*0.66 (0.36 to 1.15)0.71 (0.39 to 1.20)1
  • BMD, bone mineral density; BMI, body mass index; RF, rheumatoid factor status; DAS, disease activity score; HAQ, health assessment questionnaire; SHS, Sharp–van der Heijde score; SDC, smallest detectable change.

  • The tertile with no BMD loss is used as reference population.

  • *Spine L2–4. †Total hip.