Table 1 Characteristics of the sample

Age, year: mean ± SD (median)

67.8 ± 7.8 (69.0)

61.7 ± 10.7 (64.0)

0.0001

Weight, kg: mean ± SD

72.4 ± 13.8

73.4 ± 14.5

0.358

Height, cm: mean ± SD

169.6 ± 6.6

171.4 ± 7.0

0.007

BMI, kg/m²: mean ± SD

25.1 ± 4.6

24.9 ± 4.1

0.751

Education (%)

 Primary or less

90.1

80.8

0.011

 Secondary or higher

9.9

19.2

Smoking (%)

 Non-smoker

23.0

24.5

0.900

 Ex-smoker

61.5

59.4

 Current smoker

15.5

16.2

Alcohol intake

 Non-drinker

67.9

59.7

0.176

 <6.4 g/day

15.8

19.5

 >6.4 g/day

16.3

20.8

Family history of prostate cancer (%)

16.1

11.0

0.116

Vitamin use

22.8

30.0

0.102

Cases only (% n)

 Low-grade cancer^a

43.5 (95)

–

 High-grade cancer^b

53.2 (116)

–

 Unknown

3.2 (7)

–

Serum folate. nmol/L: mean ± SD (median)

12.3 ± 4.1 (12.4)

9.7 ± 4.2 (9.1)

0.0001

Folate intake (μg/d): mean ± SD (median)

754 ± 274 (757)

793 ± 294 (768)

0.158