Table 1 Baseline characteristics of 488,196 participants stratified by the frequency of salt added to food in UK Biobank study

Age, mean (SD), years

56.52 (8.08)

56.41 (8.12)

56.98 (8.04)

55.91 (8.27)

Female sex, n (%)

153,415 (56.55)

74,648 (54.58)

27,939 (49.41)

12,293 (52.14)

Whites, n (%)

259,100 (95.5)

127,655 (93.34)

52,824 (93.42)

20,646 (87.56)

Townsend deprivation index, median (IQR)

− 2.32 (− 3.73–0.18)

− 2.05 (− 3.59–0.66)

− 1.93 (− 3.54–0.9)

− 0.93 (− 3.07–2.47)

BMI, mean (SD), kg/m²

27.12 (4.68)

27.58 (4.77)

27.76 (4.76)

27.97 (5.05)

 < 18.5

1507 (0.56)

616 (0.45)

265 (0.47)

169 (0.72)

18.5–24.9

94,606 (34.87)

42,201 (30.86)

16,203 (28.66)

6632 (28.13)

25.0–29.9

113,666 (41.9)

58,687 (42.91)

24,661 (43.61)

9830 (41.69)

 ≥ 30.0

60,281 (22.22)

34,522 (25.24)

15,036 (26.59)

6738 (28.58)

Missing

1251 (0.46)

737 (0.54)

379 (0.67)

209 (0.89)

Education, n (%)

College or university

93,358 (34.41)

42,573 (31.13)

16,934 (29.95)

4750 (20.15)

Vocational

30,502 (11.24)

16,279 (11.9)

6993 (12.37)

2989 (12.68)

Upper secondary

31,705 (11.69)

14,642 (10.71)

5830 (10.31)

1857 (7.88)

Lower secondary

70,712 (26.06)

36,561 (26.73)

15,003 (26.53)

6327 (26.83)

Others

40,560 (14.95)

24,011 (17.56)

10,699 (18.92)

7018 (29.77)

Missing

4474 (1.65)

2697 (1.97)

1085 (1.92)

637 (2.7)

Household income, £

 < 18,000

49,007 (18.06)

26,554 (19.42)

11,792 (20.85)

6506 (27.59)

18,000–30,999

58,269 (21.48)

29,497 (21.57)

12,453 (22.02)

4973 (21.09)

31,000–51,999

61,426 (22.64)

30,357 (22.2)

12,114 (21.42)

4204 (17.83)

52,000–100,000

49,433 (18.22)

23,056 (16.86)

9191 (16.25)

2750 (11.66)

 > 100,000

13,282 (4.9)

6165 (4.51)

2486 (4.4)

622 (2.64)

Missing

39,894 (14.7)

21,134 (15.45)

8508 (15.05)

4523 (19.18)

Employment, n (%)

Employed

157,089 (57.9)

79,475 (58.11)

31,419 (55.57)

12,443 (52.77)

Unemployed

20,491 (7.55)

11,499 (8.41)

5179 (9.16)

3578 (15.18)

Retired

91,398 (33.69)

44,452 (32.5)

19,365 (34.25)

7192 (30.5)

Missing

2333 (0.86)

1337 (0.98)

581 (1.03)

365 (1.55)

Physical activity, n (%)

Recommended level

140,265 (51.7)

68,667 (50.21)

27,729 (49.04)

10,689 (45.33)

Insufficient

75,229 (27.73)

37,798 (27.64)

15,326 (27.1)

5619 (23.83)

Inactive

39,995 (14.74)

20,768 (15.19)

9600 (16.98)

4970 (21.08)

Missing

15,822 (5.83)

9530 (6.97)

3889 (6.88)

2300 (9.75)

Current smoking, n (%)

21,571 (7.95)

15,362 (11.23)

8566 (15.15)

5537 (23.48)

Moderate drinking, n (%)

146,975 (54.17)

72,109 (52.73)

27,901 (49.34)

9804 (41.58)

Vegetables (SVs/d), mean (SD)

2.53 (1.71)

2.33 (1.67)

2.15 (1.71)

1.95 (1.86)

Fruits (SVs/d), mean (SD)

1.65 (1.09)

1.61 (1.11)

1.61 (1.16)

1.58 (1.34)

Red meat (SVs/d), mean (SD)

2.01 (1.39)

2.17 (1.45)

2.3 (1.54)

2.43 (1.78)

Processed meat (SVs/d), mean (SD)

1.37 (1.34)

1.54 (1.38)

1.7 (1.47)

1.86 (1.62)

Urinary sodium excretion, mean (SD), mg/24 h

4075.52 (1224.12)

4177.61 (1251.93)

4220.79 (1272.24)

4351.5 (1328.88)

Urinary potassium excretion, mean (SD), mg/24 h

2806.43 (660.18)

2764.41 (663.78)

2730.87 (665.2)

2678.48 (665.63)

Hypertension, n (%)

152,444 (56.19)

74,621 (54.56)

31,193 (55.17)

12,895 (54.69)

Diabetes, n (%)

15,820 (5.83)

8511 (6.22)

3503 (6.2)

1568 (6.65)

Atrial fibrillation, n (%)

3994 (1.47)

1942 (1.42)

833 (1.47)

338 (1.43)

Congestive heart failure, n (%)

277 (0.1)

162 (0.12)

72 (0.13)

41 (0.17)

Stroke, n (%)

4651 (1.71)

2240 (1.64)

1004 (1.78)

512 (2.17)

Asthma, n (%)

31,831 (11.73)

16,873 (12.34)

6972 (12.33)

3217 (13.64)