Table 2

General baseline characteristics of the cohort according to total and different types of fish intake: EPIC-Norfolk Study

Portions/week
Total fishWhite fish
<1≥1<1≥1
n*2,33019,11212,7819,124
Incident diabetes*93607447274
Age (years)56.9 ± 9.258.2 ± 9.257.0 ± 9.259.7 ± 9.0
Sex (women)1,204 (51.7)10,649 (55.7)6,666 (52.2)5,461 (59.9)§
BMI (kg/m2)26.1 ± 3.926.3 ± 3.926.3 ± 3.926.2 ± 3.8
Waist circumference (cm)87.9 ± 12.487.8 ± 12.388.3 ± 12.387.3 ± 12.2§
Family history of diabetes294 (12.6)2,406 (12.6)447 (3.5)274 (3.0)
Smokers, current359 (15.6)2,146 (11.3)1,664 (13.1)896 (9.9)§
Education level
    1 (lowest)933 (40.1)7,321 (38.3)4,915 (38.5)3,569 (39.2)
    2279 (12.0)2,528 (13.2)1,682 (13.2)1,184 (13.0)
    3814 (35.0)6,724 (35.2)4,556 (35.7)3,109 (34.1)
    4 (highest)303 (13.0)2,526 (13.2)1,621 (12.7)1,253 (13.8)
Physical activity
    Inactive697 (29.9)5,477 (28.7)3,705 (29.0)2,623 (28.8)
    Moderately inactive636 (27.3)5,581 (29.2)3,604 (28.2)2,746 (30.1)
    Moderately active546 (23.4)4,433 (23.2)3,018 (23.6)2,051 (22.5)
    Active451 (19.4)3,620 (18.9)2,453 (19.2)1,704 (18.7)
Total energy intake (kcal/day)1,839.5 ± 566.12,068.6 ± 597.42§2,010.4 ± 598.22,090.8 ± 596.9§
Alcohol intake (g/day)2.3 (0–9.4)4.7 (0.8–11.0)§3.6 (0.8–10.5)4.9 (0.8–11.3)§
Fruit and vegetable intake (g/day)340.2 (229.1–478.7)418.2 (295.7–571.2)374.6 (258.3–517.1)460.4 (335.2–623.6)§
Plasma vitamin C (μmol/l)53 (38–66)55 (42–66)§53 (40–65)56 (44–68)§
Fish oil supplements at baseline535 (23.0)6,023 (31.5)3,499 (27.4)3,222 (35.3)§
<1≥1<1≥1
n*14,0597,86520,3191,608
Incident diabetes*50222065074
Age (years)58.3 ± 9.358.0 ± 9.158.2 ± 9.257.4 ± 9.1
Sex (women)7,388 (52.6)4,760 (60.5)§11,203 (55.1)943 (58.6)§
BMI (kg/m2)26.3 ± 3.926.2 ± 3.926.2 ± 3.826.7 ± 4.1
Waist circumference (cm)88.5 ± 12.386.8 ± 12.1§87.8 ± 12.288.6 ± 12.9
Family history of diabetes1,714 (12.2)1,036 (13.2)2,546 (12.5)209 (13.0)
Smokers, current1,833 (13.2)735 (9.4)§2,345 (11.6)223 (14.0)
Education level
    1 (lowest)5,624 (40.0)2,876 (36.6)7,924 (39.0)581 (36.2)
    21,744 (12.4)1,123 (14.3)2,644 (13.0)221 (13.8)
    34,978 (35.4)2,690 (34.2)7,089 (34.9)580 (36.1)
    4 (highest)1,702 (12.1)1,171 (14.9)§2,650 (13.1)223 (13.9)
Physical activity
    Inactive4,351 (31.0)1,984 (25.2)5,868 (28.9)464 (28.9)
    Moderately inactive3,946 (28.1)2,403 (30.6)5,884 (29.0)465 (28.9)
    Moderately active3,169 (22.5)1,903 (24.2)4,744 (23.4)333 (20.7)
    Active2,592 (18.4)1,575 (20.0)§3,822 (18.8)346 (21.5)
Total energy intake (kcal/day)1,999.0 ± 596.02,124.0 ± 597.2§2,035.5 ± 594.72,145.5 ± 645.5§
Alcohol intake (g/day)3.6 (0.8–10.5)5.1 (1.0–11.4)§4.1 (0.8–10.6)7.4 (1.6–16.1)§
Fruit and vegetable intake (g/day)375.4 (261.6–519.0)471.8 (347.0–635.3)§404.9 (283.0–556.2)478.4 (344.4–663.0)§
Plasma vitamin C (μmol/l)53 (39–65)57 (45–68)§54 (41–66)54 (42–67)
Fish oil supplements at baseline3,888 (27.7)2,828 (36.0)§6,205 (30.5)516 (32.1)
  • Data are means ± SD, n (%), or median (IQR) unless otherwise stated. P values correspond to t test for continuous variables, χ2 test for categorical variables, and Wilcoxon rank-sum test (for medians).

  • *Because of missing values for categories of fish intake numbers do not total 21,984, the cohort total (missing: total fish, 542; white fish, 79; oily fish, 60; and shellfish, 57). Similarly, numbers of cases do not total 725 because of missing values for fish intake (missing: total fish, 25; white fish, 4; oily fish, 3; and shellfish, 1).

  • P ≤ 0.05;

  • P ≤ 0.01;

  • §P ≤ 0.0001.