Table 1.
Baseline Characteristics of Case Patients and Controls.*
| Characteristic | Case Patients | Controls | P Value† |
|---|---|---|---|
| Women | |||
| No. of participants | 359 | 359 | |
| Age — yr | 60.3±6.1 | 60.3±6.1 | |
| White race — %‡ | 92.5 | 92.5 | |
| Body-mass index§ | 30.9±6.1 | 26.0±4.9 | <0.001 |
| Alcohol use — g/day | 2.62±7.4 | 4.19±8.3 | 0.007 |
| Current smoking — % | 14.2 | 13.7 | 0.83 |
| Strenuous physical activity ≥once/wk — % | 30.7 | 38.7 | 0.06 |
| Past postmenopausal hormone use — % | 32.0 | 27.9 | 0.22 |
| Any oral contraceptive use — % | 49.9 | 47.1 | 0.23 |
| Age at menopause — yr | 48.0±6.1 | 48.0±5.7 | 0.92 |
| Time since menopause — yr | 12.3±8.2 | 12.1±7.9 | 0.88 |
| Natural cause of menopause — % | 63.0 | 69.4 | 0.08 |
| Age at menarche, <12 yr — % | 25.4 | 21.7 | 0.46 |
| Age at first pregnancy of ≥6-mo gestation, <25 yr — % | 56.8 | 48.8 | 0.05 |
| Family history of diabetes — % | 48.5 | 24.0 | <0.001 |
| History of hypertension — % | 50.1 | 30.4 | <0.001 |
| ≥5 Pregnancies — % | 30.1 | 34.0 | 0.10 |
| Currently married — % | 63.5 | 65.2 | 0.15 |
| College graduate — % | 30.4 | 38.7 | 0.05 |
| SHBG — nmol/liter | 22.3±13.8 | 36.9±17.4 | <0.001 |
| SHBG SNP — no./total no. with data (%) | |||
| rs6257 | 0.08 | ||
| Variant allele C | 76/337 (22.6) | 65/344 (18.9) | |
| Wild-type allele T | 261/337 (77.4) | 279/344 (81.1) | |
| rs6258 | 0.91 | ||
| Variant allele T | 2/339 (0.6) | 4/347 (1.2) | |
| Wild-type allele C | 337/339 (99.4) | 343/347 (98.8) | |
| rs6259 | 0.33 | ||
| Variant allele A | 66/342 (19.3) | 82/337 (24.3) | |
| Wild-type allele G | 276/342 (80.7) | 255/337 (75.7) | |
| Men | |||
| No. of participants | 170 | 170 | |
| Age — yr | 63.7±7.6 | 63.7±7.6 | |
| White race — %‡ | 85.3 | 85.3 | |
| Body-mass index§ | 28.9±3.9 | 25.5±3.4 | <0.001 |
| Alcohol use of ≥1 drink/wk — % | 61.2 | 62.4 | 0.16 |
| Current smoking — % | 6.5 | 1.2 | 0.06 |
| Vigorous physical activity ≥1 day/wk — % | 55.3 | 65.9 | 0.34 |
| Current multivitamin use — % | 27.7 | 27.1 | 0.90 |
| Systolic blood pressure — mm Hg | 133±14 | 127±11 | <0.001 |
| Hyperlipidemia — % | 67.1 | 58.8 | 0.09 |
| Family history of diabetes — % | 32.9 | 17.1 | 0.05 |
| SHBG — nmol/liter | 19.6±7.2 | 27.3±10.7 | <0.001 |
| SHBG SNP — no./total no. with data (%) | |||
| rs6257 | 0.64 | ||
| Variant allele C | 33/167 (19.8) | 29/164 (17.7) | |
| Wild-type allele T | 134/167 (80.2) | 135/164 (82.3) | |
| rs6259 | 0.98 | ||
| Variant allele A | 27/167 (16.2) | 41/163 (25.2) | |
| Wild-type allele G | 140/167 (83.8) | 122/163 (74.8) | |
*
Plus–minus values are means ±SD. SHBG denotes sex hormone–binding globulin, and SNP single-nucleotide polymorphism.
†
P values for continuous variables were calculated by means of mixed-effects models used to determine the mean difference between case patients and controls; for categorical variables, by means of tests for homogeneity across levels, from conditional logistic-regression analysis; and for SNPs, by means of tests of Hardy–Weinberg equilibrium among controls. P values are not shown for the variables used to match case patients and controls (age and race).
‡
Race was self-reported.
§
The body-mass index is the weight in kilograms divided by the square of the height in meters.