Table 1.
Prospective studies of spinal Bone Mineral Density (BMD) change by ovulatory menstrual cycles compared with ovulatory disturbances (anovulation and short luteal phases within normal length cycles). BMD is by Quantitative Computed Tomography (*) or Dual Energy X-ray Absorptiometry (+). All data are shown as mean ± SD.
| Manuscript | Number women | Duration (years) | Age ± SD (range) | Body Mass Index | # Cycles/year | Cycle length (days) | % Bone change/year-spine | |
|---|---|---|---|---|---|---|---|---|
| Normal∙ | Ovulatory disturbances | |||||||
| Prior 1990 [15] | 66 | 1 | 33.7 ± 7.1 (20–42) | 22.0 (18–24.9) | 10 (6 to 13 cycles) | 28.2 ± 2.6 | (*) +0.2 | (*) –3.3 |
| Prior 1996 [51] | 27 | 4 | 35.9 ± 4.9 | 21.7 (18–24.9) | 1.5 (3–46 cycles) | 27.8 ± 2.4 | (*) n = 14 −0.98° | (*) n = 13 − 0.94° |
| Waller 1996 [52] | 53 | 1.5 | 33.4 ± 4.3 | 2.7 | (+) −0.05 | (+) +0.55 | ||
| Waugh 2007 [53] | 189 | 2 | 32.4 ± 4.6 (21–40) | 24.3 (range not given) | 5 | 28.9 ± 3.9 | (+) +1.6 | (+) −0.4 |
| Bedford 2010 [48] | 123 | 2 | 22.1 ± 3.3 (19–35) | 21.8 ± 2.5 | 6.8 ± 7.0 | 30.8 ± 4.1 | (+) +1.9 | (+) +0.7 |
|
| ||||||||
| Totals (Mean) | 458 | 2.1 | 31.4 | 22.5 | 6.6 | 28.9 | +0.53 | −0.68 |
°Based on a median split of % all cycles with ovulatory disturbances. “Normal” = 0%–33% of all cycles with ovulatory disturbances and “Ovulatory Disturbances” = 34%–100% of cycles with ovulatory disturbances.
∙“Normal" means normal menstrual cycle length with ovulation and a normal luteal phase length
# Numbers of cycles/year in which ovulation and ovulatory disturbances as well as cycle length were documented.
means not recorded.