Table 1 Selected baseline characteristics of study participants by study groups in the UK Biobank

From: Blood metabolic biomarkers and colorectal cancer risk: results from large prospective cohort and Mendelian randomisation analyses

Characteristics

 

Colorectal cancer

All subjects (N = 230,420)

Cases (N = 2410)

Non-cases (N = 228,010)

P-value

Age (year), median (25th–75th percentile)

58 (50–63)

62 (56–66)

57 (50–63)

<0.001

Male sex, %

47.4

58.7

47.3

<0.001

White race, %

94.8

96.5

94.8

<0.001

Education, %

   

<0.001

 College/university degree

32.8

30.7

32.9

 

 Some professional qualifications

27.7

27.3

27.7

 

 Secondary education

22.1

21.4

22.1

 

 None of the above

17.4

20.6

17.3

 

BMI (kg/m2), median (25th – 75th percentile)

26.9 (24.3–30.0)

27.6 (25.1–30.5)

26.9 (24.3–30.0)

<0.001

Waist-to-hip ratio, median (25th–75th percentile)

0.88 (0.81–0.94)

0.91 (0.83–0.96)

0.88 (0.81–0.94)

<0.001

Physical activitya, %

   

0.16

 None

18.1

19.7

18.1

 

 Intermediate

68.0

66.8

68.0

 

 Intense

13.9

13.5

13.9

 

Processed/red meat intakeb, %

   

<0.001

 ≤4 points

29.0

23.9

29.0

 

 5–7 points

51.7

52.7

51.7

 

 ≥8 points

19.3

23.4

19.3

 

Fruit/vegetables intake, %

   

0.87

 ≤1 serving per day

4.2

4.2

4.2

 

 2–4 servings per day

54.5

55.0

54.4

 

 ≥5 servings per day

41.3

40.8

41.4

 

Alcohol consumption, %

   

<0.001

 Never or seldomc

30.8

28.1

30.8

 

 1–4 times per week

49.7

48.3

49.7

 

 Almost daily

19.5

23.6

19.5

 

Tobacco smoking, %

   

<0.001

 Never

55.2

47.1

55.3

 

 Former or current, lightd

37.5

45.4

37.4

 

 Current, heavy

7.3

7.5

7.3

 

Family history of colorectal cancer, %

10.8

14.8

10.8

<0.001

Ever received colorectal cancer screening, %

30.0

35.0

29.9

<0.001

Cholesterol-lowering medication use, %

17.2

24.2

17.1

<0.001

Fasting time (h), %

   

0.23

 <3 h

25.5

25.5

25.5

 

 3–5 h

63.5

62.4

63.5

 

 >5 h

11.0

12.1

11.0

 
  1. Abbreviations: BMI, body mass index.
  2. aIntense physical activity is defined as having 6–7 days/week of moderate activity and 3–5 days/week of vigorous activity, or having 6–7 days/week of vigorous activity; intermediate physical activity is defined as having 1-5 days/week of moderate activity, or 1–2 days/week of vigorous activity.
  3. bThis variable was summed across four variables measuring frequency of intakes of processed meat, beef, lamb/mutton, and pork. The original four variables were coded as: never (0), less than once a week (1), once a week (2), 2–4 times a week (3), 5–6 times a week (4), once or more daily (5). The derived variable had a range from 0 to 20 points and was categorised into three levels.
  4. cSeldom alcohol consumption is defined as special occasions only, or 1–3 times a month.
  5. dLight current smoking is defined as smoking <20 pack-years; heavy current smoking is defined as smoking ≥20 pack-year.
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