Table 2.
Demographics of study population. N for all variables is as shown except where indicated. HBM = high bone mass, ChS = Chingford 1000-women study, HCS = Hertfordshire cohort study, SD = standard deviation, BMI = body mass index, BMD = bone mineral density, L1–L4 = 1st to 4th lumbar vertebrae. BMD variables standardised according to scanner type (Hologic for Chingford/HCS controls, mixed Lunar/Hologic for HBM cases and family controls) using standard equations [54,55].
| HBM cases (N = 311) |
Family controls (N = 183) |
ChS controls (N = 599) |
HCS controls (N = 209) |
Combined controls (N = 991) |
|
|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |
| Age (years) | 60.8 (14.3) | 54.0 (16.1) | 62.1 (10.0) | 75.2 (2.61) | 63.4 (12.5) |
| BMI (kg/m2) | 30.6 (5.83) | 28.0 (4.77) | 27.0 (4.79) | 27.7 (4.34) | 27.3 (4.71) |
| BMD total hip (g/cm2) | 1.27a (0.19) | 1.00c (0.14) | 0.91e (0.13) | 0.97 (0.14) | 0.94g (0.14) |
| BMD L1–L4 (g/cm2) | 1.55b (0.19) | 1.18d (0.17) | 1.04f (0.17) | 1.10 (0.20) | 1.08h (0.18) |
| N (%) | N (%) | N (%) | N (%) | N (%) | |
| Females | 231 (74.3) | 85 (46.5) | 599 (100) | 122 (58.4) | 806 (81.3) |
a
N = 300.
b
N = 299.
c
N = 180.
d
N = 181.
e
N = 519.
f
N = 583.
g
N = 908.
h
N = 973.