Table 3.
No infertility | Age at first report of infertility | P value, test for trend§ | |||
---|---|---|---|---|---|
≤25 y | 26–30 y | >30 y | |||
CHD|| | |||||
Events, n | 966 | 230 | 240 | 64 | |
Person‐years | 1 676 149 | 238 335 | 376 255 | 115 744 | |
Age‐adjusted model* | 1.00 [Referent] | 1.43 (1.24–1.65) | 1.07 (0.92–1.23) | 0.87 (0.68–1.13) | <0.001 |
Multivariable model 1† | 1.00 [Referent] | 1.40 (1.21–1.63) | 1.10 (0.95–1.28) | 0.88 (0.68–1.14) | <0.001 |
Multivariable model 2‡ | 1.00 [Referent] | 1.26 (1.09–1.46) | 1.08 (0.93–1.25) | 0.91 (0.70–1.19) | 0.004 |
CVD¶ | |||||
Events, n | 1489 | 311 | 351 | 99 | |
Person‐years | 1 675 650 | 238 263 | 376 140 | 115 711 | |
Age‐adjusted model* | 1.00 [Referent] | 1.27 (1.12–1.44) | 1.01 (0.90–1.13) | 0.87 (0.71–1.07) | 0.004 |
Multivariable model 1† | 1.00 [Referent] | 1.25 (1.10–1.42) | 1.04 (0.92–1.17) | 0.87 (0.70–1.07) | 0.003 |
Multivariable model 2‡ | 1.00 [Referent] | 1.14 (1.01–1.29) | 1.02 (0.90–1.15) | 0.90 (0.73–1.11) | 0.08 |
Stroke | |||||
Events, n | 531 | 83 | 111 | 37 | |
Person‐years | 1676 650 | 238 514 | 376 389 | 115 787 | |
Age‐adjusted model* | 1.00 [Referent] | 0.98 (0.77–1.23) | 0.89 (0.73–1.10) | 0.89 (0.64–1.25) | 0.43 |
Multivariable model 1† | 1.00 [Referent] | 0.97 (0.77–1.23) | 0.91 (0.74–1.12) | 0.89 (0.63–1.25) | 0.50 |
Multivariable model 2‡ | 1.00 [Referent] | 0.91 (0.72–1.15) | 0.90 (0.73–1.12) | 0.91 (0.64–1.28) | 0.28 |
BMI indicates body mass index; CHD, coronary heart disease; CVD, cardiovascular disease; ICD‐8, International Classification of Diseases, Eighth Revision; MI, myocardial infarction; and NHSII, Nurses’ Health Study II.
Models were jointly stratified by age (months) and calendar time (months).
Model 2 additionally adjusted for age at menarche (<12, 12, 13, ≥14 years of age), White Non‐Hispanic race and ethnicity (yes, no), marital status (ever married, never), daily aspirin use (yes, no), oral contraceptive use (never, past, current), gravidity (≤1, 2, 3, or ≥4 pregnancies), BMI at age 18 years (<19, 20.5–21.9, 22–24.9, 25–29.9, or ≥30 kg/m2), and breastfeeding duration (<3, 3–12, or >12 months).
Model 3 is additionally adjusted for current BMI (<24.9, 25–29.9, 30–34.9, or ≥35 kg/m2), cigarette smoking status and current dose (never, past, current 1–34 cigarettes/d, current ≥35 cigarettes/d), physical activity (0, 0.1–1.0, 1.1–2.4, 2.5–5.9, or ≥6 h/wk), and Alternative Healthy Eating Index 2010 diet quality score (quintiles).
Tests for linear trend were conducted by modeling categories of age at first report of infertility as an ordinal variable assigning integer values.
CHD includes fatal and nonfatal MI, fatal coronary heart disease (ICD‐8: 410, 412), and self‐reported coronary artery bypass grafting/angioplasty/stent.
CVD includes CHD and fatal and nonfatal cerebrovascular accident or transient ischemic attack (ICD‐8: 430–437).