Table 1.
Baseline characteristics of 257 healthy, premenopausal women from the BioCycle study
| Characteristic | n = 257 |
|---|---|
| Age in years (range, 18–44 yr) | 27.3 (8) |
| Cycle length, mean from 2 cycles (d) | 28.8 (4.1) |
| Race, n (%) | |
| White | 153 (60%) |
| Black | 50 (20%) |
| Asian/Pacific Islander | 41 (16%) |
| Other race | 13 (4%) |
| Household income, n (%) | |
| Less than $19,999 | 55 (21%) |
| $20,000–$39,999 | 61 (24%) |
| $40,000–$74,999 | 72 (28%) |
| $75,000–$99,999 | 43 (17%) |
| $100,000 or over | 24 (9%) |
| Missing | 2 (1%) |
| Education, n (%) | |
| High school or less | 32 (12%) |
| Some college | 100 (39%) |
| Bachelor/associate degree | 97 (38%) |
| Graduate program | 28 (11%) |
| Married | 65 (25%) |
| Past smoker, n (%) | 43 (17%) |
| Current smoker, n (%) | 10 (4%) |
| Height (cm) | 164.1 (6) |
| Weight (kg) | 64.8 (11) |
| Body mass index (kg/m2) | 24.1 (4) |
| Underweight, BMI < 18.5 | 9 (3%) |
| Normal, 18.5 ≤ BMI < 25 | 157 (61%) |
| Overweight, 25 ≤ BMI < 30 | 66 (26%) |
| Obese, BMI ≥ 30 | 25 (10%) |
| Physical activity (METs/d) | 1281 (1907) |
| Mean caloric intake (kcal/d) | 1608 (405) |
| Glucose (mg/dl) | 87 (7) |
| Insulin (μU/ml)a | 6 (4–8) |
| HOMA-IRa | 1.3 (0.8–1.8) |
| Follicular SHBG (nmol/liter)a | 43.3 (30.9–61.5) |
All hormone values are from cycle 1. Values are expressed as mean (sd) and are from d 2 unless otherwise indicated. Conversion factors: Glucose, mg/dl × 0.0555 = mmol/liter; insulin, pIU/liter × 6.945 = pmol/liter; estradiol, pg/ml × 3.671 = pmol/liter; progesterone, ng/ml × 3.18 = nmol/liter; FSH mIU/ml × 1.0 = IU/liter; LH, mIU/ml × 1.0 = IU/liter. METs, Metabolic equivalents.
a
Median (25th–75th percentile) for cycle 1.