TABLE 1.
Unadjusted baseline characteristics by serum magnesium quintiles: the ARIC study, 1987–19891
| Quintiles of serum magnesium | |||||
|---|---|---|---|---|---|
| Characteristic | 1 | 2 | 3 | 4 | 5 |
| n | 3278 | 2669 | 3094 | 2726 | 2679 |
| Magnesium, mEq/L | 1.45 [0.60–1.50] | 1.55 [1.55–<1.60] | 1.65 [1.60–<1.70] | 1.70 [1.70–<1.75] | 1.80 [1.75–2.35] |
| Age, y | 54 ± 6 | 54 ± 6 | 54 ± 6 | 54 ± 6 | 54 ± 6 |
| Female | 1986 (60.6) | 1562 (58.5) | 1706 (55.1) | 1467 (53.8) | 1452 (54.2) |
| African American | 1439 (43.9) | 671 (25.1) | 745 (24.1) | 529 (19.4) | 442 (16.5) |
| Education | |||||
| <High school | 1029 (31.5) | 564 (21.2) | 625 (20.2) | 536 (19.7) | 541 (20.2) |
| High school graduate | 1243 (38.0) | 1125 (42.2) | 1329 (43.0) | 1144 (42.0) | 1080 (40.4) |
| >High school | 1000 (30.6) | 977 (36.7) | 1135 (36.7) | 1042 (38.3) | 1053 (39.4) |
| Sport index | 2.3 ± 0.8 | 2.4 ± 0.8 | 2.4 ± 0.8 | 2.5 ± 0.8 | 2.5 ± 0.8 |
| Smoking status | |||||
| Current | 927 (28.3) | 666 (25.0) | 813 (26.3) | 667 (24.5) | 680 (25.4) |
| Former | 974 (29.8) | 819 (30.7) | 977 (31.6) | 886 (32.5) | 885 (33.1) |
| Never | 1373 (41.9) | 1181 (44.3) | 1303 (42.1) | 1170 (43.0) | 1113 (41.6) |
| Pack-years smoking | 315 ± 446 | 296 ± 416 | 310 ± 419 | 299 ± 416 | 303 ± 406 |
| Drinking status | |||||
| Current | 1558 (47.8) | 1511 (56.8) | 1766 (57.2) | 1672 (61.7) | 1621 (60.7) |
| Former | 702 (21.5) | 459 (17.2) | 564 (18.3) | 432 (15.9) | 464 (17.4) |
| Never | 1002 (30.7) | 692 (26.0) | 755 (24.5) | 606 (22.4) | 586 (21.9) |
| Ethanol intake, g/wk | 40 ± 106 | 38 ± 87 | 44 ± 95 | 44 ± 93 | 45 ± 92 |
| Diabetes | 760 (23.3) | 260 (9.8) | 288 (9.3) | 168 (6.2) | 122 (4.6) |
| BMI, kg/m2 | 29 ± 6 | 28 ± 5 | 27 ± 5 | 27 ± 5 | 27 ± 5 |
| HDL-C, mg/dL | 53 ± 19 | 54 ± 18 | 53 ± 17 | 54 ± 17 | 54 ± 17 |
| LDL-C, mg/dL | 130 ± 42 | 133 ± 39 | 136 ± 41 | 136 ± 38 | 138 ± 39 |
| Total cholesterol, mg/dL | 213 ± 44 | 214 ± 41 | 215 ± 42 | 215 ± 40 | 217 ± 42 |
| Lipid-lowering medication use | 82 (2.5) | 57 (2.2) | 97 (3.2) | 59 (2.2) | 73 (2.7) |
| Systolic BP, mm Hg | 126 ± 20 | 121 ± 18 | 120 ± 18 | 119 ± 18 | 119 ± 17 |
| Antihypertension medication use | 1373 (41.9) | 726 (27.2) | 813 (26.3) | 609 (22.4) | 574 (21.4) |
| eGFR, mL · min−1 · 1.73 m−2 | 106 ± 18 | 104 ± 14 | 103 ± 14 | 101 ± 14 | 100 ± 15 |
| eGFR category | |||||
| ≥90 mL · min−1 · 1.73 m−2 | 2813 (85.8) | 2300 (86.2) | 2638 (85.3) | 2246 (82.4) | 2190 (81.8) |
| 60 to <90 mL · min−1 · 1.73 m−2 | 410 (12.5) | 348 (13.0) | 436 (14.1) | 451 (16.5) | 457 (17.1) |
| 15 to <60 mL · min−1 · 1.73 m−2 | 55 (1.7) | 21 (0.8) | 20 (0.7) | 29 (1.1) | 32 (1.2) |
| Hormone therapy use (in women only) | 407 (20.5) | 317 (20.3) | 295 (17.3) | 271 (18.5) | 232 (16.0) |
1
n = 14,446. Values are mean ± SD or median [range] for continuous variables and n (%) for categorical variables. ARIC, Atherosclerosis Risk in Communities; BP, blood pressure; eGFR, estimated glomerular filtration rate; HDL-C, HDL cholesterol; LDL-C, LDL cholesterol.