Bone mineral density and fracture data

At the baseline examination, as well as at Year 10 follow-up, BMD was measured at the lumbar spine (L1–L4) and femoral neck region (gm/cm²) using dual x-ray absorptiometry (QDR 1000; Hologic, Waltham, MA cross-calibrated with a QDR 2000/w at follow-up). Reproducibility was tested on 20 paired subjects 1 week apart and found to be 1-2% for spine and 2-3% for the hip (Keen RW, 1998). Detailed data were sought on all fractures and falls occurring during the first 48 months of the study. Information was obtained between 1989 and 1993 by interview at each annual visit and by phone calls every 6 months to reduce error due to poor recall. A total of 145 validated fractures were observed during the first 48 months of the study, the majority were of the distal forearm (40, or 27.6%) and vertebrae (41, or 28.3%). The remaining fractures were of the hip (6, or 4.1%), lower limb and foot (30, or 20.7%), upper limb and hand (20, or 13.8%), and sternum (8, or 5.5%).

The women have a fracture/falls questionnaire administered by telephone every 6 months, and at Year 15 (present) 407 women have experienced a fracture. Not all fractures have yet been validated with hospital and GP records. The women now have average age of 65, there have been 96 colles fractures, and up to Year 10, 52 vertebral fractures.

Bone loss at the spine and hip over 9 years of study:

Spine BMD in Year 1 and Year 10 Hip BMD in Year 1 and Year 10