Table 1.

Study population

Subject	Sex (F or M)	Age (years)	Smoker	Number of cigarette day−1	Years on smoke
1	F	51	Yes	20	25
2	M	54	Yes	12	20
3	F	43	No	—	—
4	M	63	Yes	15	40
5	M	50	No	—	—
6	F	28	Yes	10	10
7	M	43	Yes	30	18
8	M	50	No	—	—
9	M	46	No	—	—
10	F	29	No	—	—
11	M	37	Yes	20	15
12	F	35	No	—	—
13	M	69	No	—	—
14	F	56	Yes	25	32
15	M	48	No	—	—
16	M	62	Yes	16	34
17	F	70	No	—	—
18	F	45	Yes	20	15
19	M	39	No	—	—
20	M	45	Yes	35	20
21	M	55	No	—	—
22	F	76	No	—	—
23	F	33	Yes	12	8
24	M	67	Yes	10	30
25	M	58	Yes	12	33