Table 1.

Baseline characteristics of participants stratified by case-control status

Characteristic	Measure	Cases (N=1,461)	Controls (N=1,507)	P*
Age	mean (SD)	62.5 (5.1)	62.3 (5.1)	0.2
Ethnicity (white)		98.5%	98.7%	0.3
BMI (kg/m2)**	mean (SD)	27.9 (3.7)	28.2 (4.1)	0.1
Tobacco use**	Current smoker	20.2%	17.3%	0.1
	Ever smoked	63.3%	65.5%	0.3
Alcohol consumption in the past 12 months**	Almost daily or more often	38.5%	37.8%	0.5
	Once or twice per week	41.2%	42.4%
	Once or twice per month	8.5%	6.9%
	Special occasions or never	11.9%	12.9%
Vitamin supplement use in past 12 months (yes/no)**		7.8%	7.9%	0.9

Circulating vitamin and metabolite concentrations	median (5th – 95th percentile)	median (5th – 95th percentile)
Folate (nmol/L)	15.9 (6.1 – 51.4)	15.8 (6.2 – 52.3)	0.6
Vitamin B12 (pmol/L)	307 (156 – 542)	299 (158 – 521)	0.1
Holo-haptocorrin (pmol/L)	247 (119 – 439)	240 (120 – 425)	0.04
Holo-transcobalamin (pmol/L)	57 (23 – 117)	56 (24 – 119)	0.9
Total-transcobalamin (pmol/L)	860 (612 – 1269)	874 (602 – 1270)	0.1
Total homocysteine (μmol/L)	11.1 (7.8 – 17.6)	11.1 (7.7 – 17.7)	0.9

^*Chi-squared test (proportions), Student’s t-test (means) or two-sample Wilcoxon rank-sum (Mann-Whitney) test (medians)

^**Numbers of cases and controls for whom these data were available: BMI (1,183 cases, 1,105 controls); current smoker (846 cases, 808 controls); ever smoked (1,208 cases, 1,117 controls); alcohol consumption (1,204 cases, 1,116 controls); vitamin supplementation (875 cases, 831 controls)