Table 1.
Characteristics of the study population at baseline by tertiles of fish consumption (N = 62,629).
| Fish Consumption | ||||
|---|---|---|---|---|
| All (N = 62,629) | 1st Tertile (0–16.7 g/day) (N = 20,681) |
2nd Tertile (16.7–31.1 g/day) (N = 19,749) |
3rd Tertile (31.1–261 g/day) (N = 22,199) |
|
| Age at baseline (years) | 52.5 (6.5) | 52.3 (6.5) | 52.1 (6.4) | 53.1 (6.5) |
| Educational level | ||||
| <High School | 8322 (13.3) | 3091 (14.9) | 2542 (12.8) | 2689 (12.1) |
| Up to two-level university | 32,032 (51.1) | 10,754 (52.0) | 10,123 (51.3) | 11,155 (50.3) |
| ≥Three-level university | 22,275 (35.6) | 6836 (33.1) | 7084 (35.9) | 8355 (37.6) |
| Smoking status | ||||
| Current smoker | 8269 (13.2) | 2779 (13.5) | 2532 (12.8) | 2958 (13.3) |
| Non smoker | 33,558 (53.6) | 11,401 (55.1) | 10,622 (53.8) | 11,535 (52.0) |
| Former smoker | 20,802 (33.2) | 6501 (31.4) | 6595 (33.4) | 7706 (34.7) |
| Passive smoking in childhood | 8972 (14.3) | 3043 (14.7) | 2880 (14.6) | 3049 (13.7) |
| Gastrointestinal transit | ||||
| Normal | 45,104 (72.0) | 14,814 (71.6) | 14,319 (72.5) | 15,971 (71.9) |
| Diarrhoea | 1720 (2.8) | 569 (2.8) | 541 (2.8) | 610 (2.8) |
| Constipation | 8579 (13.7) | 2922 (14.1) | 2631 (13.3) | 3026 (13.6) |
| Alternating diarrhoea/constipation | 7226 (11.5) | 2376 (11.5) | 2258 (11.4) | 2592 (11.7) |
| Body mass index (kg/m2) | 22.9 (3.2) | 22.7 (3.1) | 22.8 (3.2) | 23.2 (3.3) |
| Physical activity (MET.h/week) | 44.8 (28.7) | 44.2 (28.7) | 44.2 (28.1) | 45.9 (29.4) |
| Hypothyroidism | 1287 (2.1) | 366 (1.8) | 401 (2.0) | 520 (2.4) |
| Diabetes mellitus | 3780 (6.0) | 1106 (5.3) | 1087 (5.5) | 1587 (7.1) |
| Daily caloric intake (kcal/day) | 2136.3 (542.4) | 2034.9 (525.4) | 2159.0 (529.4) | 2210.4 (555.1) |
| Food consumption | ||||
| Fish (g/day) | 28.6 (21.7) | 9.6 (4.3) | 23.0 (3.5) | 51.3 (20.6) |
| Fruits (g/d day) | 255.0 (169.2) | 244.7 (171.2) | 248.7 (161.8) | 270.3 (172.6) |
| Vegetables (g/day) | 278.4 (134.6) | 245.4 (125.6) | 271.0 (124.2) | 315.7 (142.3) |
| Olive oil (g/day) | 4.8 (5.6) | 3.8 (5.1) | 4.5 (5.3) | 5.8 (6.2) |
| Cereal (g/day) | 191.2 (99.2) | 186.6 (98.0) | 194.0 (97.2) | 193.1 (102.0) |
| Dairy products (g/day) | 249.7 (194.3) | 235.3 (190.7) | 243.3 (187.2) | 268.8 (202.3) |
| Meat (g/day) | 103.4 (50.2) | 97.4 (50.4) | 109.3 (50.4) | 103.7 (49.1) |
| Glucose (g/day) | 236.1 (61.8) | 230.9 (61.3) | 238.6 (61.2) | 238.7 (62.4) |
| Incident RA after baseline | 480 (0.8) | 172 (0.8) | 121 (0.6) | 187 (0.8) |
Results are expressed as N (%) for categorical variables and mean (STD) for continuous variables. Abbreviations: RA: rheumatoid arthritis; MET: metabolic equivalents of task: g: gram; kcal: kilocalories.