Table 4.
Results of linear regression analysis (unadjusted and adjusted) for the relationship between patterns of oral contraceptive use and IGF-1 levels (ng/ml) for women aged 31 to 40 years.
| Unadjusted | Adjusteda | |||||||
|---|---|---|---|---|---|---|---|---|
| No. | Mean (SD) | Beta | 95%CI | P | Beta | 95%CI | P | |
| OC Use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.37 | Reference | 0.30 | ||
| Ever | 111 | 176.8 (56.1) | 9.6 | -11.7, 30.9 | 10.8 | -9.7, 31.3 | ||
| Never | 37 | 167.2 (58.7) | Reference | 0.18 | Reference | 0.09 | ||
| Past | 87 | 181.4 (56.9) | 14.2 | -7.7, 36.1 | 16.4 | -4.7, 37.6 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -36.3, 22.2 | -7.7 | -35.6, 20.2 | ||
| Age at first use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.04 | Reference | 0.04 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -35.8, 21.7 | -7.8 | -35.4, 19.8 | ||
| Past | ||||||||
| ≤ 18 years | 47 | 168.8 (52.7) | 1.4 | -22.5, 25.7 | 5.5 | -17.8, 28.9 | ||
| 19 to 24 years | 28 | 188.8 (61.0) | 21.5 | -5.9, 49.0 | 22.5 | -4.2, 49.1 | ||
| ≥ 25 years | 12 | 213.8 (50.6) | 46.5 | 10.1, 83.0 | 43.8 | 8.8, 78.8 | ||
| Time since first use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.01 | Reference | 0.03 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -35.4, 21.3 | -7.5 | -35.0, 19.9 | ||
| Past | ||||||||
| ≥ 20 years | 25 | 156.0 (47.4) | -11.3 | -39.3, 16.8 | -1.4 | -29.3, 26.4 | ||
| 15 to 19 years | 32 | 179.2 (54.5) | 12.0 | -14.2, 38.1 | 11.8 | -13.7, 37.4 | ||
| < 15 years | 30 | 205.0 (58.4) | 37.8 | 11.2, 64.4 | 35.1 | 9.3, 61.0 | ||
| Time since last use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.35 | Reference | 0.30 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -36.4, 22.3 | -7.7 | -35.8, 20.4 | ||
| Past | ||||||||
| <5 years | 26 | 183.0 (58.1) | 15.7 | -12.9, 44.4 | 14.4 | -13.0, 42.0 | ||
| 5 to <10 years | 29 | 188.3 (61.9) | 21.1 | -6.7, 48.8 | 20.7 | -6.1, 47.6 | ||
| ≥ 10 years | 32 | 173.9 (51.7) | 6.7 | -20.3, 33.8 | 14.2 | -12.0, 40.5 | ||
| Duration of use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.23 | Reference | 0.22 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -36.3, 22.2 | -7.7 | -35.7, 20.3 | ||
| Past | ||||||||
| <5 years | 21 | 197.0 (65.2) | 29.8 | -0.7, 60.2 | 25.8 | -3.6, 55.2 | ||
| 5 to < 10 years | 33 | 178.6 (50.2) | 11.4 | -15.3, 38.1 | 16.3 | -9.5, 42.0 | ||
| ≥ 10 years | 33 | 174.3 (57.4) | 7.1 | -19.6, 33.8 | 10.2 | -15.7, 36.2 | ||
| Year of first use | ||||||||
| Never | 37 | 167.2 (58.7) | Reference | 0.03 | Reference | 0.02 | ||
| Current | 24 | 160.2 (51.1) | -7.0 | -35.9, 21.8 | -8.1 | -35.6, 19.4 | ||
| Past | ||||||||
| 1979 to 1994 | 73 | 175.4 (54.8) | 8.2 | -14.0, 30.4 | 10.8 | -10.6, 32.2 | ||
| 1995 to 2004 | 14 | 212.9 (59.2) | 45.6 | 11.1, 80.1 | 46.6 | 13.4, 79.8 | ||
a Adjusted for current weight (75th percentile and above vs. below), days since last reported menstrual cycle (<=14 vs. >14), and current physical activity at least once per week (ever vs. never)