Table 1. Baseline characteristics and unadjusted associations with incident CHD events (n = 2193; number of CHD events = 351).
| Variable | Mean ± SD / n (%) | HR (95% CI) | p |
| Age | 73.50±2.85 | 1.03 (1.00, 1.07) | 0.09 |
| Age (categories) | 0.03* | ||
| 70–71 | 672 (30.6) | ||
| 72–75 | 934 (42.6) | 0.99 (0.77, 1.27) | |
| 76–78 | 464 (21.2) | 1.05 (0.78, 1.41) | |
| 79 | 123 (5.6) | 1.59 (1.04, 2.43) | |
| Gender | |||
| Men | 981 (44.7) | ||
| Women | 1212 (55.3) | 0.52 (0.42, 0.65) | <0.001 |
| Race | |||
| White | 1293 (59.0) | ||
| Black | 900 (41.0) | 0.96 (0.78, 1.19) | 0.73 |
| Site | |||
| Memphis | 1125 (51.3) | ||
| Pittsburgh | 1068 (48.7) | 0.99 (0.79, 1.22) | 0.89 |
| Education | 0.29* | ||
| <high school | 532 (24.3) | ||
| High school graduate | 734 (33.6) | 0.81 (0.61, 1.07) | |
| Postsecondary | 922 (42.1) | 0.87 (0.67, 1.13) | |
| Smoking status | 0.03* | ||
| Never | 1016 (46.3) | ||
| Former | 956 (43.6) | 1.41 (1.13, 1.77) | |
| Current | 221 (10.1) | 1.49 (1.04, 2.12) | |
| Alcohol, drinks/wk | 0.41* | ||
| <1 | 1535 (70.3) | ||
| 1–7 | 482 (22.1) | 0.88 (0.68, 1.14) | |
| >7 | 166 (7.6) | 1.17 (0.81, 1.70) | |
| Physical activity, kcal/wk† | 0.20* | ||
| <500 | 1148 (52.3) | ||
| 500–1500 | 598 (27.3) | 0.96 (0.74, 1.23) | |
| ≥1500 | 447 (20.4) | 1.18 (0.91, 1.54) | |
| Hypertension‡ | 1258 (57.4) | 1.28 (1.03, 1.59) | 0.02 |
| Diabetes mellitus | 292 (13.3) | 1.63 (1.24, 2.13) | <0.001 |
| Body mass index, kg/m2 | 27.41±4.91 | 1.02 (1.00, 1.04) | 0.10 |
| Abdominal circumference | 99.43±13.54 | 1.01 (1.00, 1.02) | 0.02 |
| Systolic blood pressure, per 10 mmHg | 135.72±20.63 | 1.09 (1.04, 1.15) | <0.001 |
| Diastolic blood pressure, per 10 mmHg | 71.59±11.66 | 1.12 (1.02, 1.22) | 0.01 |
| Total cholesterol, per 10 mg/dl | 204.83±37.93 | 0.99 (0.96, 1.01) | 0.31 |
| HDL-cholesterol, per 10 mg/dl | 55.46±17.12 | 0.87 (0.81, 0.93) | <0.001 |
| Total/HDL-cholesterol | 3.98±1.22 | 1.15 (1.06, 1.25) | <0.001 |
| LDL-cholesterol, per 10 mg/dl | 122.87±34.44 | 1.01 (0.98, 1.04) | 0.50 |
| Triglycerides, mg/dl∥ | 116 (87–160) | 1.11 (0.89, 1.39) | 0.36 |
| Glucose, per 10 mg/dl | 102.46±31.88 | 1.05 (1.03, 1.08) | <0.001 |
| Framingham risk score, %¶ | <0.001 | ||
| <5% | 468 (21.3) | ||
| 5–9.99% | 557 (25.4) | 1.35 (0.92, 1.99) | |
| 10–19.99% | 543 (24.8) | 2.12 (1.47, 3.04) | |
| ≥20% | 625 (28.5) | 3.06 (2.17, 4.31) | |
| Creatinine, mg/dl∥ | 1 (0.9–1.1) | 1.96 (1.33, 2.87) | 0.001 |
| GFR, ml/min/1.73 m2 # | 61.15±15.05 | 1.00 (0.99, 1.01) | 0.87 |
| GFR (categories)** | 0.63 | ||
| ≥80 | 525 (23.9) | 1.00 | |
| 70–79.99 | 536 (24.5) | 1.11 (0.83,1.49) | |
| 60–69.99 | 555 (25.3) | 0.87 (0.64,1.18) | |
| <60 | 576 (26.3) | 1.00 (0.75,1.35) | |
| Medication use | |||
| Lipid-lowering | 229 (10.4) | 1.04 (0.75, 1.46) | 0.79 |
| Ace inhibitors | 273 (12.4) | 1.14 (0.84, 1.54) | 0.39 |
| Hormone replacement therapy | 48 (2.2) | 0.82 (0.37, 1.85) | 0.64 |
| Aspirin | 412 (18.8) | 1.31 (1.02, 1.69) | 0.03 |
Abbreviations: SD: standard deviation; HR: hazard ratio; CI: confidence interval; HDL: high-density lipoprotein; LDL: low-density lipoprotein; GFR: glomerular filtration rate.
*p for trend.
Physical activity was assessed by questionnaire about all types of walking and exercise performed in the prior week [14].
Defined by self-report of hypertension and use of anti-hypertensive medications, or measured SBP≥140 and/or DBP≥90 mmHg.
Expressed as median (25%–75%), because of skewed distribution. The effect of the logarithm of the covariates on the CHD is measured.
Classes of CHD risk at 10 years, according to Framingham functions [2].
Glomerular filtration rate (GFR) was estimated using the MDRD equation: GFR = 175 * Creatinine−1.154 * Age−0.203 * (1.212*Iblack+Iwhite)* (0.742*Ifemale+Imen) [32].
**Quartiles were used instead of clinical cut-offs to avoid categories with few participants. In particular, categories of GFR<15 and within 15–29.99 were collapsed with the category 30–59.99 (only 0.2% in the class of GFR<15 and 0.5% in the class of GFR within 15–29.99) and a ≥80 category was replaced to the usual ≥90 (only 7% for GFR≥90).