Table 1.
Demographic and clinical characteristics at baseline among women who underwent bilateral oophorectomy and age-matched referent women.
| Characteristicsa | Bilateral oophorectomy (n=270) | Referent women (n=270) | p-valueb | ||
|---|---|---|---|---|---|
| N | % or median (IQR) | N | % or median (IQR) | ||
| Age at index (years) | -- | ||||
| <40 | 34.1 | 34.1 | |||
| 40–45 | 65.9 | 65.9 | |||
| Calendar year at index | -- | ||||
| 1988–1997 | 44.8 | 44.8 | |||
| 1998–2007 | 55.2 | 55.2 | |||
| Race | 0.21 | ||||
| White | 97.0 | 93.7 | |||
| Black | 1.5 | 2.6 | |||
| Asian | 0.7 | 3.7 | |||
| Other | 0.7 | 0.0 | |||
| Hispanic ethnicity | 1.5 | 1.5 | >0.99 | ||
| Years of education | 0.003 | ||||
| ≤12 | 37.9 | 24.2 | |||
| 13–16 | 50.9 | 56.8 | |||
| >16 | 11.2 | 18.9 | |||
| Household incomec | 0.17 | ||||
| <$42,000 | 31.1 | 21.6 | |||
| $42,000–56,999 | 28.5 | 25.6 | |||
| $57,000–71,999 | 19.5 | 25.6 | |||
| ≥$72,000 | 21.0 | 27.1 | |||
| Smoking status | 0.009 | ||||
| Never | 50.4 | 58.5 | |||
| Former | 21.5 | 25.2 | |||
| Current | 28.1 | 16.3 | |||
| Hysterectomy status | <0.001 | ||||
| No | 1.5 | 94.4 | |||
| Before | 10.7 | 5.6 | |||
| Concurrent | 87.8 | ||||
| Prior unilateral oophorectomy | 13.3 | 2.2 | <0.001 | ||
| Indication for oophorectomyd | -- | ||||
| Benign ovarian condition | 50.7 | ||||
| No ovarian condition | 49.3 | ||||
| Hypertensione | 20.7 | 14.4 | 0.053 | ||
| Hyperlipidemiaf | 43.0 | 34.4 | 0.04 | ||
| Systolic blood pressure (mmHg)g | 252 | 120.0 (111.0–130.0) | 239 | 120.0 (110.0–128.0) | 0.04 |
| Diastolic blood pressure (mmHg)g | 252 | 76.0 (70.0–82.0) | 239 | 74.0 (68.0–82.0) | 0.09 |
| Weight (kg)g | 246 | 72.5 (61.9–92.8) | 234 | 70.2 (60.9–79.4) | 0.002 |
| Body mass index (kg/m2)g | 246 | 26.7 (23.2–33.6) | 234 | 25.1 (22.4–29.5) | <0.001 |
| Total cholesterol (mg/dL)g | 161 | 197.0 (170.0–221.0) | 143 | 188.0 (167.0–211.0) | 0.49 |
| Triglycerides (mg/dL)g | 156 | 110.0 (73.0–159.0) | 133 | 97.0 (64.0–141.0) | 0.053 |
| HDL cholesterol (mg/dL)g | 144 | 50.0 (44.0–59.0) | 127 | 54.0 (44.0–66.0) | 0.32 |
| LDL cholesterol (mg/dL)g | 119 | 115.0 (96.0–139.0) | 107 | 107.0 (91.0–130.0) | 0.75 |
IQR = interquartile range.
Women with unknown data were not included in the tests for differences between the groups..
The p-values were calculated using tests which accounted for the matched pairs (McNemar’s tests or Bowker’s tests of symmetry for categorical variables or Wilcoxon signed rank tests for continuous variables). Non-parametric tests were used for the continuous variables because the paired differences for systolic blood pressure, triglycerides, and LDL cholesterol were not normally distributed.
Income was derived from the 2000 United States Census. Each woman was assigned the median household income for the census block group in which she lived at the index date.
The indication was listed by the gynecologist in the medical record at the time of oophorectomy. Benign ovarian conditions include benign tumors, cyst, or endometriosis in either ovary. No ovarian condition includes women without a benign ovarian condition in either ovary. Historically, the terms ‘prophylactic’, ‘elective’, or ‘incidental’ oophorectomy were used; however, we avoided these terms.
Hypertension was defined as systolic blood pressure >140 mmHg, diastolic blood pressure >90 mmHg, or onset of antihypertensive medication use before the index date.
Hyperlipidemia was defined as total cholesterol ≥200 mg/dL, triglycerides ≥150 mg/dL, HDL cholesterol ≤50 mg/dL, or onset of lipid lowering medication use before the index date.
Measurements closest to and within 3 years before in the index date.