Table 3.
Number of observations made in each 12-month period prior to and after the final menstrual period (FMP) and the relation between time to or from FMP and menstrually-defined menopause transition stages
| Menstrually-defined menopause transition stages a | |||||||
|---|---|---|---|---|---|---|---|
| Number of months before (negative sign) or after (positive sign) FMP b | Number of Observations | Crude Lumbar Spine BMD c | Crude Femoral Neck BMD c | Premenopausal Number, % | Early Perimenopausal Number, % | Late Perimenopausal Number, % | Postmenopausal Number, % |
| −60 to −49 | 485 | 1.07 | 0.83 | 178 (36.8%) | 304 (62.8%) | 2 (0.4%) | 0 (0.0%) |
| −48 to −37 | 563 | 1.07 | 0.83 | 155 (27.6%) | 396 (70.5%) | 11 (1.9%) | 0 (0.0%) |
| −36 to −25 | 618 | 1.07 | 0.83 | 116 (18.8%) | 481 (77.8%) | 21 (3.4%) | 0 (0.0%) |
| −24 to −13 | 697 | 1.07 | 0.83 | 64 (9.2%) | 552 (79.7%) | 77 (11.1%) | 0 (0.0%) |
| −12 to FMP | 742 | 1.05 | 0.82 | 32 (4.3%) | 503 (68.0%) | 205 (27.7%) | 0 (0.0%) |
| FMP to +12 | 871 | 1.03 | 0.82 | 8 (0.9%) | 266 (30.5%) | 535 (61.4%) | 62 (7.1%) |
| 13 to 24 | 703 | 1.00 | 0.79 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 703 (100%) |
| 25 to 36 | 602 | 0.99 | 0.78 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 602 (100%) |
| 37 to 48 | 456 | 0.97 | 0.77 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 456 (100%) |
| 49 to 60 | 372 | 0.97 | 0.77 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 372 (100%) |
Menstrually-defined menopause stages are based on self-reported bleeding patterns obtained by annual interview. Menopause transition stage categories are: premenopausal, characterized by regular menses; early perimenopausal, defined as menses within the prior 3 months but less predictable compared to participant’s prior pattern; late perimenopausal defined as having had at least 3 months, but less than 12 consecutive months, of amenorrhea; and postmenopausal characterized by having experienced 12 or more months without menses.
The number of months either before or after the FMP that each on-study BMD was obtained. In this manuscript, based on patterns of BMD loss in relation to the FMP, the following terminology is used. The time interval between 5 years and 1 year prior to the FMP is called “pre-transmenopause”. The interval spanning 1 year before to 2 years after the FMP is termed the “transmenopause”. The interval between 2 and 5 years after the FMP is called the “postmenopause”. These FMP-based categories are distinct from the menstrually-based menopause transition category definitions given in footnote “a”.
Crude mean values of lumbar spine or femoral neck BMD in each one-year interval before or after the FMP