Table 1. Basic characteristics of study participants according to serum ALP levels in men and women.
| Variables | Quartiles of ALP levels＊, U/L | p value | |||
|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | ||
| Men (n= 11,408) | ＜69 | 69-84 | 84-100 | ＞100 | |
| No. (%) | 2676 (23.5) | 2901 (25.4) | 3050 (26.7) | 2781 (24.4) | |
| Age, y | 65.2 (6.5) | 65.4 (6.5) | 65.2 (6.3) | 65.1 (6.8) | 0.40 |
| BMI†, kg/m2 | 24.4 (3.2) | 24.3 (3.1) | 24.3 (3.1) | 24.1 (3.1) | ＜0.001 |
| High school or above†, No. (%) | 1131 (42.3) | 1191 (41.1) | 1228 (40.3) | 1051 (37.8) | 0.005 |
| SBP†, mmHg | 132.1 (19.6) | 133.1 (20.2) | 133.9 (20.1) | 134.5 (20.5) | ＜0.001 |
| DBP†, mmHg | 79.1 (11.4) | 79.4 (11.9) | 79.9 (11.8) | 80.4 (12.2) | ＜0.001 |
| Fasting blood glucose†, mmol/L | 5.7 (5.2-6.3) | 5.7 (5.2-6.2) | 5.7 (5.2-6.3) | 5.7 (5.2-6.3) | 0.29 |
| Total cholesterol†, mmol/L | 4.9 (4.3-5.5) | 4.8 (4.3-5.5) | 4.8 (4.3-5.5) | 4.8 (4.2-5.5) | 0.13 |
| Total glyceride†, mmol/L | 1.1 (0.8-1.6) | 1.2 (0.8-1.6) | 1.2 (0.9-1.7) | 1.3 (0.9-1.8) | ＜0.001 |
| HDL-C†, mmol/L | 1.4 (1.2-1.6) | 1.3 (1.2-1.6) | 1.3 (1.1-1.6) | 1.3 (1.1-1.6) | ＜0.001 |
| LDL-C†, mmol/L | 2.8 (2.4-3.3) | 2.8 (2.4-3.3) | 2.8 (2.3-3.4) | 2.8 (2.3-3.4) | 0.40 |
| Current smoker†, No. (%) | 966 (36.1) | 1091 (37.6) | 1257 (41.2) | 1300 (46.8) | ＜0.001 |
| Current drinker†, No. (%) | 1297 (48.5) | 1324 (45.6) | 1314 (43.1) | 1117 (40.2) | ＜0.001 |
| Physical activity, No. (%) | 1939 (72.5) | 2139 (73.7) | 2257 (74.0) | 2006 (72.1) | 0.29 |
| Diabetes, No. (%) | 487 (18.2) | 475 (16.4) | 567 (18.6) | 561 (20.2) | 0.003 |
| Hyperlipidemia, No. (%) | 1047 (39.1) | 1205 (41.5) | 1340 (43.9) | 1299 (46.7) | ＜0.001 |
| Hypertension, No. (%) | 1432 (53.5) | 1600 (55.2) | 1720 (56.4) | 1642 (59.0) | ＜0.001 |
| Family history of CVD, No. (%) | 261 (9.8) | 214 (7.4) | 227 (7.4) | 240 (8.6) | 0.003 |
| Anticoagulants use, No. (%) | 40 (1.5) | 44 (1.5) | 45 (1.5) | 40 (1.4) | 1.00 |
| Aspirin use, No. (%) | 300 (11.2) | 303 (10.4) | 322 (10.6) | 259 (9.3) | 0.14 |
| eGFR†, mL/min/1.73 m2 | 82.6 (70.5-93.8) | 81.6 (70.0-92.9) | 80.8 (69.2-93.0) | 80.2 (68.6-91.5) | ＜0.001 |
| WBC†, 109/L | 5.6 (4.8-6.7) | 5.9 (4.9-7.0) | 6.0 (5.1-7.0) | 6.2 (5.2-7.3) | ＜0.001 |
| ALT†, U/L | 19.0 (15.0-26.0) | 19.0 (15.0-26.0) | 20.0 (15.0-27.0) | 21.0 (16.0-29.0) | ＜0.001 |
| ALP, U/L | 61.0 (54.0-65.0) | 76.0 (73.0-80.0) | 91.0 (87.0-96.0) | 115.0 (106.0-127.0) | ＜0.001 |
| Women (n= 14,981) | ＜71 | 71-87 | 87-105 | ＞105 | |
| No. (%) | 3720 (24.8) | 3661 (24.4) | 3861 (25.8) | 3739 (25.0) | |
| Age, y | 56.5 (8.0) | 58.6 (7.9) | 59.8 (7.9) | 60.6 (7.7) | ＜0.001 |
| BMI†, kg/m2 | 23.8 (3.3) | 24.0 (3.3) | 24.1 (3.4) | 24.4 (3.4) | ＜0.001 |
| High school or above†, No. (%) | 1757 (47.2) | 1610 (44.0) | 1575 (40.8) | 1306 (34.9) | ＜0.001 |
| SBP†, mmHg | 125.6 (19.7) | 127.4 (19.5) | 129.4 (19.7) | 132.0 (20.9) | ＜0.001 |
| DBP†, mmHg | 76.4 (11.1) | 76.7 (11.2) | 77.3 (10.9) | 78.4 (11.7) | ＜0.001 |
| Fasting blood glucose†, mmol/L | 5.4 (5.1-5.9) | 5.5 (5.1-6.0) | 5.6 (5.1-6.1) | 5.6 (5.2-6.2) | ＜0.001 |
| Total cholesterol†, mmol/L | 5.0 (4.4-5.7) | 5.2 (4.6-5.8) | 5.2 (4.6-5.9) | 5.3 (4.6-5.9) | ＜0.001 |
| Total glyceride†, mmol/L | 1.1 (0.8-1.6) | 1.2 (0.9-1.7) | 1.3 (0.9-1.8) | 1.4 (1.0-1.9) | ＜0.001 |
| HDL-C†, mmol/L | 1.5 (1.3-1.7) | 1.5 (1.3-1.7) | 1.5 (1.2-1.7) | 1.4 (1.2-1.7) | ＜0.001 |
| LDL-C†, mmol/L | 2.8 (2.4-3.3) | 3.0 (2.5-3.5) | 3.0 (2.5-3.6) | 3.0 (2.5-3.6) | ＜0.001 |
| Current smoker†, No. (%) | 47 (1.3) | 70 (1.9) | 81 (2.1) | 100 (2.7) | ＜0.001 |
| Current drinker†, No. (%) | 420 (11.3) | 341 (9.3) | 328 (8.5) | 263 (7.0) | ＜0.001 |
| Physical activity, No. (%) | 2523 (67.8) | 2541 (69.4) | 2696 (69.8) | 2629 (70.3) | ＜0.001 |
| Diabetes, No. (%) | 435 (11.7) | 485 (13.3) | 569 (14.7) | 682 (18.2) | ＜0.001 |
| Hyperlipidemia, No. (%) | 1213 (32.6) | 1434 (39.2) | 1621 (42.0) | 1647 (44.1) | ＜0.001 |
| Hypertension, No. (%) | 1448 (38.9) | 1594 (43.5) | 1815 (47.0) | 1990 (53.2) | ＜0.001 |
| Family history of CVD, No. (%) | 576 (15.5) | 514 (14.0) | 528 (13.7) | 439 (11.7) | ＜0.001 |
| Anticoagulants use, No. (%) | 45 (1.2) | 52 (1.4) | 56 (1.5) | 53 (1.4) | 0.80 |
| Aspirin use, No. (%) | 308 (8.3) | 314 (8.6) | 351 (9.1) | 343 (9.2) | 0.47 |
| Postmenopausal women, No. (%) | 2584 (69.5) | 3011 (82.3) | 3452 (89.4) | 3467 (92.7) | ＜0.001 |
| WBC†, 109/L | 5.2 (4.3-6.2) | 5.3 (4.5-6.3) | 5.5 (4.6-6.6) | 5.7 (4.8-6.7) | ＜0.001 |
| eGFR†, mL/min/1.73 m2 | 88.1 (74.5-99.5) | 85.3 (72.2-97.2) | 82.3 (70.1-94.6) | 80.5 (68.8-92.9) | ＜0.001 |
| ALT†, U/L | 17.0 (13.0-23.0) | 18.0 (14.0-24.0) | 19.0 (14.0-26.0) | 20.0 (15.0-28.0) | ＜0.001 |
| ALP, U/L | 61.0 (54.0-67.0) | 79.0 (75.0-83.0) | 95.0 (91.0-100.0) | 121.0 (112.0-135.0) | ＜0.001 |
Note: Normally distributed variables were presented as mean (SD), non-normally distributed variables were presented as median (IQR) and categorical variables were presented as a number (%). Abbreviations: ALP, alkaline phosphatase; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; CVD, cardiovascular disease; WBC, white blood cell; eGFR, estimated glomerular filtration rate; ALT, alanine aminotransferase.
＊The quartiles of ALP levels in men were Q1 (＜69 U/L), Q2 (69-84 U/L), Q3 (84-100 U/L), and Q4 (＞100 U/L), while the quartiles of ALP levels in women were Q1 (＜71 U/L), Q2 (71-87 U/L), Q3 (87-105 U/L), and Q4 (＞105 U/L), respectively.
†Data were incomplete for these variables. 159 (1.4%), 65 (0.6%), 106 (0.9%), 143 (1.3%), 139 (1.2%), 369 (3.2%), 15 (0.1%), 15 (0.1%), 14 (0.1%), 31 (0.3%), 18 (0.2%), 22 (0.2%), 809 (7.1%), and 100 (0.9%) of men had missing data for BMI, education, fasting blood glucose, SBP, DBP, total cholesterol, triglyceride, HDL-C, LDL-C, smoking status, drinking status, eGFR, WBC, and ALT, respectively. 206 (1.4%), 110 (0.7%), 146 (1.0%), 186 (1.2%), 185 (1.2%), 465 (3.1%), 23 (0.2%), 16 (0.1%), 20 (0.1%), 97 (0.6%), 25 (0.2%), 29 (0.2%), 1058 (7.1%), and 136 (0.9%) of women had missing data for BMI, education, fasting blood glucose, SBP, DBP, total cholesterol, triglyceride, HDL-C, LDL-C, smoking status, drinking status, eGFR, WBC, and ALT, respectively.