Table 1.
Baseline Characteristics of Participants by Decile of Alanine Aminotransferase Level, United States, 1988–1994
| Characteristic | Decile of ALT Levela |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 |
2 |
3 |
4–9 |
10 |
||||||
| Mean (SD) | % | Mean (SD) | % | Mean (SD) | % | Mean (SD) | % | Mean (SD) | % | |
| ALT level, IU/L | 6.7 (1.4) | 9.4 (1.3) | 10.8 (1.8) | 17.0 (5.4) | 44.1 (23.4) | |||||
| Age, years | ||||||||||
| Mean | 47.8 (20.4)*** | 45.4 (18.8) | 45.4 (18.4) | 44.7 (16.4) | 41.4 (14.6)*** | |||||
| Median | 42.3 (28.6–65.7)b | 40.3 (29.5–60.9) | 41.3 (28.8–59.9) | 41.2 (31.0–56.1) | 37.8 (29.5–50.1) | |||||
| Female sex | 59.7*** | 43.9** | 48.7* | 53.0 | 53.8 | |||||
| Race/ethnicity | ||||||||||
| Non-Hispanic white | 76.6 | 76.6 | 79.5 | 78.1 | 72.6** | |||||
| Non-Hispanic black | 16.0*** | 14.6*** | 10.6** | 8.8 | 7.1** | |||||
| Mexican-American | 2.5*** | 3.6** | 3.5*** | 5.1 | 10.4*** | |||||
| Other | 4.9* | 5.2* | 6.4 | 8.0 | 10.0 | |||||
| Education, years | ||||||||||
| <12 | 30.2*** | 25.6 | 25.8 | 22.8 | 23.6 | |||||
| 12 | 33.4 | 35.5 | 32.1 | 33.7 | 34.4 | |||||
| >12 | 36.4** | 39.0 | 42.1 | 43.5 | 42.0 | |||||
| Body mass indexc | 24.8 (4.8)*** | 24.9 (4.9)*** | 25.3 (5.1)*** | 26.9 (5.6) | 29.5 (6.4)*** | |||||
| Waist:hip circumference ratio | 89.3 (9.4)*** | 90.0 (9.2)* | 89.9 (9.0)*** | 91.1 (9.0) | 93.5 (8.5)*** | |||||
| Abnormal glucose statusd | 6.3 | 4.4** | 5.1* | 6.9 | 12.9*** | |||||
| Total cholesterol, mg/dL | 200 (44)*** | 198 (42)*** | 199 (43)*** | 206 (42) | 213 (46)** | |||||
| HDL cholesterol, mg/dL | 53.2 (16.0)*** | 51.2 (15.0) | 52.3 (15.7)** | 50.4 (15.2) | 46.7 (15.4)*** | |||||
| Systolic blood pressure, mm Hg | 123 (20) | 123 (19) | 122 (18) | 122 (17) | 123 (16) | |||||
| Diastolic blood pressure, mm Hg | 71.8 (10.2)*** | 73.1 (10.0)*** | 73.1 (9.4)*** | 74.4 (9.8) | 77.2 (10.4)*** | |||||
| C-reactive protein, >0.3 mg/dL | 31.0*** | 23.1 | 24.0 | 24.5 | 34.3*** | |||||
| Estimated GFR <60 mL/minute/1.73 m2 | 9.8*** | 6.8** | 6.2** | 4.0 | 2.3** | |||||
| Transferrin saturation, % | 24.2 (11.8)*** | 26.6 (12.8) | 25.9 (11.4) | 26.5 (11.1) | 27.2 (11.4) | |||||
| Cigarette smoking | ||||||||||
| Never smoker | 43.2* | 40.1* | 42.3* | 48.0 | 50.8 | |||||
| Former smoker | 22.2*** | 27.2 | 26.0 | 26.8 | 26.4 | |||||
| Current smoker | ||||||||||
| <1 pack/day | 12.8 | 13.4 | 14.2 | 11.1 | 13.4 | |||||
| ≥1 pack/day | 21.8*** | 19.4* | 17.6* | 14.1 | 9.4** | |||||
| Alcohol drinking | ||||||||||
| Never drinker | 16.2* | 12.6 | 13.1 | 12.5 | 14.0 | |||||
| Former drinker | 34.1 | 33.2 | 31.0 | 32.7 | 31.3 | |||||
| Current drinker | ||||||||||
| <1 drink/day | 35.9** | 40.7 | 40.8 | 40.8 | 36.6* | |||||
| 1–2 drinks/day | 8.5 | 8.4 | 9.3 | 8.3 | 8.8 | |||||
| >2 drinks/day | 5.4 | 5.1 | 5.9 | 5.7 | 9.3** | |||||
| Caffeine intake, mg/day | 255 (305)* | 222 (313) | 249 (293) | 223 (272) | 197 (223)* | |||||
| Physical activity, METs/month | 98 (127)** | 110 (126) | 116 (128) | 113 (135) | 104 (125)* | |||||
| Physical function summary score ≤8e | 35.1** | 31.8 | 27.2 | 26.7 | 31.0 | |||||
| AST level, IU/L | 15.7 (3.9)*** | 16.9 (3.7)*** | 17.6 (4.0)*** | 20.5 (5.9) | 36.3 (23.3)*** | |||||
| GGT level, IU/L | 17.5 (12.7)*** | 19.0 (14.4)*** | 20.2 (16.4)*** | 27.3 (26.9) | 63.7 (77.5)*** | |||||
Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; GFR, glomerular filtration rate; GGT, γ-glutamyltransferase; HDL, high-density lipoprotein; MET, metabolic equivalent of task; SD, standard deviation.
* P < 0.05; **P < 0.01; ***P < 0.001 (compared with 4th–9th deciles).
a ALT cutpoints were 9, 11, 13, and 33 IU/L for men and 7, 8, 9, and 22 IU/L for women.
b Numbers in parentheses, interquartile range.
c Weight (kg)/height (m)2.
d Physician-diagnosed diabetes or hemoglobin A1c concentration of ≥6.5%.