Table 3.
Linear regression analyses of female reproductive health indicators with baseline spirometry measures (n=273 441)
| Reproductive health indicator | Mean change in FEV1 z-score (95% CI) | Mean change in FVC z-score (95% CI) | Mean change in FEV1/FVC z-score (95% CI) | |||
| Unadjusted | Multiple-adjusted* | Unadjusted | Multiple-adjusted* | Unadjusted | Multiple-adjusted* | |
| Age at menarche | ||||||
| <12 years | −0.04 (-0.05 to -0.03) | −0.01 (-0.02 to 0.00) | −0.05 (-0.06 to -0.04) | −0.01 (-0.02 to -0.01) | 0.02 (0.01 to 0.03) | −0.02 (-0.03 to -0.01) |
| 12–15 years | 0 | 0 | 0 | 0 | 0 | 0 |
| >15 years | −0.08 (-0.10 to -0.06) | −0.03 (-0.05 to -0.01) | −0.06 (-0.08 to -0.04) | −0.03 (-0.05 to -0.02) | −0.05 (-0.07 to -0.02) | 0.00 (-0.02 to 0.02) |
| Menopause status | ||||||
| No | 0 | 0 | 0 | 0 | 0 | 0 |
| Yes | −0.03 (-0.04 to -0.02) | −0.04 (-0.05 to -0.02) | −0.03 (-0.04 to -0.02) | −0.04 (-0.06 to -0.03) | 0.00 (-0.01 to 0.01) | 0.01 (-0.01 to 0.02) |
| Age at natural menopause† | ||||||
| <47 years | −0.11 (-0.12 to -0.09) | −0.04 (-0.05 to -0.02) | −0.09 (-0.11 to -0.08) | −0.04 (-0.05 to -0.02) | −0.05 (-0.07 to -0.04) | −0.01 (-0.02 to 0.01) |
| 47–49 years | −0.05 (-0.07 to -0.04) | −0.02 (-0.04 to 0.00) | −0.04 (-0.06 to -0.03) | −0.02 (-0.03 to 0.00) | −0.03 (-0.05 to -0.02) | −0.01 (-0.03 to 0.01) |
| 50–52 years | 0 | 0 | 0 | 0 | 0 | 0 |
| >52 years | 0.01 (0.00 to 0.03) | 0.00 (-0.01 to 0.02) | 0.00 (-0.02 to 0.01) | 0.00 (-0.02 to 0.01) | 0.03 (0.02 to 0.05) | 0.01 (0.00 to 0.02) |
| Parity, binary | ||||||
| Nulliparous | −0.02 (-0.03 to -0.01) | −0.04 (-0.06 to -0.03) | −0.04 (-0.05 to -0.03) | −0.07 (-0.08 to -0.05) | 0.04 (0.03 to 0.05) | 0.04 (0.03 to 0.05) |
| Parous | 0 | 0 | 0 | 0 | 0 | 0 |
| Parity, ordered categories | ||||||
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | −0.02 (-0.04 to -0.01) | 0.01 (0.00 to 0.03) | −0.01 (-0.02 to 0.01) | 0.02 (0.01 to 0.04) | −0.04 (-0.06 to -0.03) | −0.02 (-0.04 to 0.00) |
| 2 | 0.04 (0.03 to 0.06) | 0.04 (0.03 to 0.06) | 0.06 (0.05 to 0.08) | 0.07 (0.06 to 0.08) | −0.03 (-0.05 to -0.02) | −0.04 (-0.06 to -0.03) |
| 3 | 0.03 (0.02 to 0.05) | 0.05 (0.04 to 0.07) | 0.05 (0.04 to 0.07) | 0.08 (0.06 to 0.09) | −0.04 (-0.06 to -0.03) | −0.04 (-0.06 to -0.03) |
| >3 | −0.03 (-0.05 to -0.01) | 0.05 (0.04 to 0.07) | −0.01 (-0.02 to 0.01) | 0.08 (0.07 to 0.10) | −0.07 (-0.08 to -0.05) | −0.06 (-0.07 to -0.04) |
| PCOS/ovarian cysts | ||||||
| No | 0 | 0 | 0 | 0 | 0 | 0 |
| Yes | −0.02 (-0.05 to 0.02) | −0.01 (-0.04 to 0.03) | −0.05 (-0.08 to -0.01) | −0.03 (-0.07 to 0.00) | 0.06 (0.03 to 0.09) | 0.05 (0.02 to 0.09) |
| Endometriosis | ||||||
| No | 0 | 0 | 0 | 0 | 0 | 0 |
| Yes | 0.01 (-0.03 to 0.04) | 0.01 (-0.02 to 0.05) | −0.02 (-0.06 to 0.01) | −0.02 (-0.05 to 0.01) | 0.06 (0.02 to 0.10) | 0.07 (0.03 to 0.10) |
| Oral contraception | ||||||
| Never used | 0 | 0 | 0 | 0 | 0 | 0 |
| Ever used | 0.07 (0.05 to 0.08) | 0.03 (0.01 to 0.04) | 0.08 (0.07 to 0.09) | 0.02 (0.01 to 0.03) | −0.01 (-0.03 to 0.00) | 0.01 (0.003 to 0.03) |
| Years of oral contraception | ||||||
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | 0.03 (0.01 to 0.04) | 0.01 (-0.01 to 0.03) | 0.04 (0.02 to 0.06) | 0.01 (-0.01 to 0.03) | −0.03 (-0.04 to -0.01) | 0.01 (-0.004 to 0.03) |
| 2-4 | 0.05 (0.04 to 0.07) | 0.02 (0.01 to 0.04) | 0.06 (0.05 to 0.08) | 0.02 (0.01 to 0.03) | 0.00 (-0.02 to 0.01) | 0.02 (0.003 to 0.03) |
| 5-9 | 0.08 (0.07 to 0.10) | 0.03 (0.02 to 0.05) | 0.09 (0.08 to 0.10) | 0.03 (0.01 to 0.04) | 0.00 (-0.02 to 0.01) | 0.02 (0.003 to 0.03) |
| 10-15 | 0.08 (0.07 to 0.10) | 0.04 (0.02 to 0.05) | 0.10 (0.08 to 0.11) | 0.04 (0.02 to 0.05) | −0.02 (-0.03 to 0.00) | 0.01 (-0.002 to 0.03) |
| >15 | 0.07 (0.05 to 0.08) | 0.02 (0.01 to 0.04) | 0.08 (0.07 to 0.10) | 0.02 (0.00, 0.03) | −0.03 (-0.04 to -0.01) | 0.01 (-0.002 to 0.03) |
| HRT | ||||||
| Never used | 0 | 0 | 0 | 0 | 0 | 0 |
| Ever used | −0.02 (-0.02 to -0.01) | 0.00 (0.00 to 0.01) | −0.01 (-0.01 to 0.00) | 0.00 (-0.01 to 0.01) | −0.02 (-0.03 to -0.01) | 0.02 (0.01 to 0.03) |
| Years of HRT | ||||||
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1-2 | −0.03 (-0.04 to -0.01) | 0.00 (-0.01 to 0.02) | −0.01 (-0.03 to 0.00) | 0.00 (-0.02 to 0.01) | −0.03 (-0.05 to -0.02) | 0.02 (0.01 to 0.04) |
| 3-5 | −0.03 (-0.04 to -0.01) | 0.00 (-0.01 to 0.02) | −0.02 (-0.03 to 0.00) | 0.00 (-0.02 to 0.02) | −0.02 (-0.04 to 0.00) | 0.02 (0.00 to 0.03) |
| 6-10 | 0.00 (-0.02 to 0.02) | 0.01 (-0.01 to 0.02) | 0.00 (-0.02 to 0.02) | 0.00 (-0.02 to 0.02) | 0.00 (-0.02 to 0.01) | 0.02 (0.00 to 0.04) |
| >10 | 0.00 (-0.02 to 0.01) | 0.00 (-0.01 to 0.02) | 0.01 (0.00 to 0.03) | 0.00 (-0.01 to 0.02) | −0.03 (-0.05 to -0.01) | 0.01 (-0.01 to 0.03) |
| Gynaecological surgery | ||||||
| No | 0 | 0 | 0 | 0 | 0 | 0 |
| Hysterectomy | −0.03 (-0.05 to -0.02) | 0.01 (0.00 to 0.03) | −0.05 (-0.06 to -0.04) | 0.00 (-0.02 to 0.01) | 0.03 (0.01 to 0.04) | 0.04 (0.02 to 0.06) |
| Bilateral | −0.05 (-0.12 to 0.02) | −0.02 (-0.08 to 0.05) | −0.07 (-0.14 to 0.00) | −0.04 (-0.11 to 0.03) | 0.04 (-0.03 to 0.12) | 0.05 (-0.02 to 0.12) |
| oophorectomy | ||||||
| Both | −0.04 (-0.05 to -0.02) | 0.00 (-0.01 to 0.02) | −0.07 (-0.08 to -0.05) | −0.02 (-0.04 to -0.01) | 0.05 (0.04 to 0.07) | 0.05 (0.04 to 0.07) |
*Adjusted for age, body mass index (log-transformed), ethnicity, education, household income, Townsend deprivation index, smoking history, asthma, maternal COPD and paternal COPD.
†Age at menopause was analysed only among women who experienced natural menopause before baseline (n=161 069).
FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; HRT, hormone replacement therapy; PCOS, polycystic ovary syndrome.