Table 1.
Baseline demographic characteristics of participants in the ARIC study according to categories of coffee consumption
| Baseline characteristics | Coffee consumption categories |
P value | ||||
|---|---|---|---|---|---|---|
| Never (n = 3792) | <1 cup/d (n = 1948) | 1 cup/d (n = 2710) | 2–3 cups/d (n = 3323) | >3 cups/d (n = 2434) | ||
| Age (yr) | 54 ± 6 | 54 ± 6 | 55 ± 6 | 54 ± 6 | 54 ± 6 | <0.001 |
| Sex, % female | 2382 (62.8) | 1045 (53.6) | 1558 (57.5) | 1739 (52.3) | 1178 (48.4) | <0.001 |
| Race, % black | 1313 (34.6) | 459 (23.6) | 1007 (37.2) | 581 (17.5) | 157 (6.5) | <0.001 |
| Education level (%) | ||||||
| Less than high school | 916 (24.2) | 394 (20.2) | 822 (30.3) | 654 (19.7) | 448 (18.4) | <0.001 |
| High school or equivalent | 1524 (40.2) | 816 (41.9) | 1006 (37.1) | 1430 (43.0) | 1089 (44.7) | |
| College or above | 1352 (35.7) | 738 (37.9) | 882 (32.6) | 1239 (37.3) | 897 (36.9) | |
| Center (%) | ||||||
| Forsyth County, NC | 854 (22.5) | 475 (24.4) | 755 (27.9) | 998 (30.0) | 596 (24.5) | <0.001 |
| Jackson, MS | 1144 (30.2) | 399 (20.5) | 912 (33.7) | 535 (16.1) | 132 (5.4) | |
| Minneapolis, MN | 814 (21.5) | 568 (29.2) | 396 (14.6) | 899 (27.1) | 1047 (43.0) | |
| Washington County, MD | 980 (25.8) | 506 (26.0) | 647 (23.9) | 891 (26.8) | 659 (27.1) | |
| Physical activity index scorea | 2.4 ± 0.8 | 2.5 ± 0.8 | 2.4 ± 0.8 | 2.5 ± 0.8 | 2.5 ± 0.8 | <0.001 |
| Smoking status (%) | ||||||
| Never smoker | 1990 (52.5) | 944 (48.5) | 1238 (45.7) | 1231 (37.0) | 553 (22.7) | <0.001 |
| Former smoker | 1073 (28.3) | 631 (32.4) | 856 (31.6) | 1199 (36.1) | 843 (34.6) | |
| Current smoker | 729 (19.2) | 373 (19.2) | 616 (22.7) | 893 (26.9) | 1038 (42.7) | |
| BMI (kg/m2) | 28 ± 6 | 28 ± 5 | 28 ± 6 | 27 ± 5 | 27 ± 5 | <0.001 |
| Total energy intake (kcal/d) | 1561 ± 594 | 1592 ± 581 | 1614 ± 595 | 1630 ± 586 | 1728 ± 619 | <0.001 |
| DASH diet score (8–40) | 25 ± 5 | 24 ± 5 | 24 ± 5 | 24 ± 5 | 24 ± 5 | <0.001 |
| SBP (mm Hg) | 123 ± 19 | 121 ± 18 | 123 ± 19 | 120 ± 18 | 117 ± 17 | <0.001 |
| DBP (mm Hg) | 75 ± 11 | 74 ± 11 | 75 ± 12 | 73 ± 11 | 71 ± 11 | <0.001 |
| MAP (mm Hg) | 91 ± 13 | 90 ± 12 | 91 ± 13 | 89 ± 12 | 87 ± 12 | <0.001 |
| Diabetes (%) | 465 (12.3) | 208 (10.7) | 337 (12.4) | 304 (9.2) | 143 (5.9) | <0.001 |
| Hypertension (%) | 1464 (38.6) | 673 (34.6) | 1100 (40.6) | 990 (29.8) | 549 (22.6) | <0.001 |
| Antihypertensive medication (%) | 1299 (34.3) | 608 (31.2) | 962 (35.6) | 851 (25.6) | 472 (19.4) | <0.001 |
| ACE inhibitors (%) | 130 (3.4) | 52 (2.7) | 95 (3.5) | 78 (2.4) | 55 (2.3) | 0.005 |
| Fasting blood glucose (mmol/l) | 6.0 ± 2.1 | 5.9 ± 1.7 | 6.1 ± 2.1 | 5.9 ± 1.8 | 5.7 ± 1.4 | <0.001 |
| Serum creatinine (μmol/l) | 95.3 ± 16.1 | 96.6 ± 16.1 | 96.3 ± 16.1 | 96.7 ± 15.7 | 96.0 ± 14.9 | 0.001 |
| Serum potassium (mmol/l) | 4.4 ± 0.5 | 4.4 ± 0.5 | 4.3 ± 0.5 | 4.5 ± 0.5 | 4.6 ± 0.5 | <0.001 |
| Serum magnesium (mmol/l) | 0.8 ± 0.1 | 0.8 ± 0.1 | 0.8 ± 0.1 | 0.8 ± 0.1 | 0.8 ± 0.1 | <0.001 |
| eGFR (ml/min per 1.73 m2) | 104 ± 15 | 103 ± 15 | 104 ± 15 | 102 ± 13 | 102 ± 12 | <0.001 |
| Alcohol intake status (%)b | ||||||
| Never | 1309 (34.5) | 478 (24.5) | 809 (29.9) | 629 (18.9) | 286 (11.8) | <0.001 |
| Former | 742 (19.6) | 317 (16.3) | 525 (19.4) | 554 (16.7) | 471 (19.4) | |
| Current (moderate) | 256 (6.8) | 177 (9.1) | 222 (8.2) | 407 (12.3) | 345 (14.2) | |
| Current (heavy) | 1485 (39.2) | 976 (50.1) | 1154 (42.6) | 1733 (52.2) | 1332 (54.7) | |
ACE, angiotensin-converting enzyme; ANOVA, analysis of variance; DASH, Dietary Approaches to Stop Hypertension; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; MAP, mean arterial pressure; SBP, systolic blood pressure; UACR, urinary albumin-to-creatinine ratio.
Data for categorical variables are presented as n (%) and were analyzed by χ2 tests. Data for continuous variables are presented as mean ± SD and were analyzed by ANOVA test.
The physical activity index included considerations of both time and intensity of the exercise or sporting activity completed during leisure time, with scores ranging from 1 (lowest) to 5 (highest).
Moderate alcohol intake was defined as follows: <1 alcoholic beverage per day for women or <2 alcoholic beverages per day for men. Heavy alcohol intake was defined as ≥1 alcoholic beverage per day for women or ≥2 alcoholic beverages per day for men.