Table 1.

Baseline characteristics of the study population in 1992

Frequency of blood donation		No donations (n=12,220)	1–5 donations (n=12,371)	6–9 donations (n=4,284)	10–19 donations (n=4,001)	20+ donations (n=3,700)
Age	years	61.1 (9. 9)	59.4 (9.5)	58.1 (9.1)	57.9 (8.9)	58.4 (8.6)
Body mass index (BMI)	kg/m²	25.3 (3.2)	25.5 (3.2)	25.6 (3.1)	25.8 (3.1)	25. 9(3.3)
	<23, %	21	18	16	14	14
	23–24.9, %	30	29	28	28	26
	25–26.9, %	24	26	27	27	28
	27–29.9, %	17	19	20	22	21
	30+, %	8	8	9	9	11
Physical activity	met-hr/week¶	21.5 (20.5)	22. 5 (20.9)	23.4 (21.0)	23.4 (21.4)	23.7 (21.3)
	Q1§, %	18	17	17	16	15
	Q2, %	18	18	16	17	18
	Q3, %	18	17	18	19	19
	Q4, %	17	18	20	18	20
	Q5, %	17	18	19	20	20
	Missing, %	11	12	10	10	8
Height	cm	178 (7.6)	178 (7.0)	179 (6.5)	179 (6.6)	179 (7.4)
Smoking history	Never, %	45	45	46	45	48
	Past, %	45	45	43	44	43
	Current, %	7	7	7	7	7
	Missing, %	3	3	4	4	2
Race	White or other, %	97	98	98	98	99
	Black or Asian, %	3	2	2	2	1
Alcohol consumption	grams/day	10.8 (14.4)	11.0 (14.1)	11.0 (13.7)	11.1 (13.7)	10.7 (13.6)
	<0.5, %	21	19	19	19	21
	0.5–4.9, %	26	27	26	25	25
	5.0–9.9, %	15	15	16	17	16
	10.0–19.9, %	18	19	20	20	19
	20+, %	17	17	17	17	17
	Missing, %	3	3	2	2	2

Values are means(SD) or percentages.

^¶METs; Metabolic Equivalents

^§Q1, Q2, Q3, Q4, and Q5 stand for 1^st, 2^nd, 3^rd, 4^th, and 5^th quintile of METs respectively