BMI–mortality association: shape independent of smoking status but different for chronic lung disease and lung cancer

Figures & data

Table 1 Baseline characteristics of the study population

Characteristic	Never	Former	Light	Heavy	Total	Missingsa
Full datasetb (%)	17,028 (47.4)	6,576 (18.3)	7,127 (19.8)	5,123 (14.3)	35,854 (100)
Analyzed observations, n (%)	16,727 (47.5)	6,468 (18.4)	7,015 (19.9)	5,002 (14.2)	35,212 (100)	702
Women, n (%)	11,124 (66.5)	2,377 (36.8)	3,441 (49.0)	1,685 (33.7)	18,627 (52.9)	0
Person-years	382,060	140,390	166,768	112,246	801,464
Years of follow-up, mean ± SD	22.8±9.0	21.7±8.9	23.8±9.3	22.4±9.1	22.8±9.1
Age, mean ± SD	47.0±16.6	48.6±14.7	42.2±14.7	41.2±12.2	45.5±15.6	0
BMI, mean ± SD	24.2±4.0	25.0±4.0	23.8±3.7	24.3±3.8	24.3±3.9
BMI categories (%)
<18.5	637 (3.9)	126 (2.0)	300 (4.3)	165 (3.3)	1,228 (3.5)	443
18.5–25 (ref)	9,817 (59.6)	3,290 (51.4)	4,311 (62.0)	2,887 (58.2)	20,305 (58.4)
25–30	4,603 (28.0)	2,355 (36.8)	1,927 (27.7)	1,565 (31.6)	10,450 (30.1)
>30	1,400 (8.5)	630 (9.8)	412 (5.9)	344 (6.9)	2,786 (8.0)
Marital status (%)
Married	10,827 (64.8)	4,909 (75.9)	4,516 (64.4)	3,176 (63.5)	23,428 (66.6)	16
Divorced	809 (4.8)	413 (6.4)	507 (7.2)	549 (11.0)	2,278 (6.5)
Single	3,594 (21.5)	807 (12.5)	1,712 (24.4)	1,148 (23.0)	7,261 (20.6)
Widowed	1,490 (8.9)	337 (5.2)	275 (3.9)	127 (2.5)	2,229 (6.3)
Other covariates
Alcohol use (%)	9,503 (57.1)	4,823 (74.7)	4,930 (70.5)	3,816 (76.4)	23,072 (65.8)	135
Healthy diet (%)	12,185 (74.0)	4,379 (69.0)	4,456 (64.9)	2,405 (48.2)	23,425 (67.5)	535
Years of education, mean ± SD	11.5±3.2	12.3±3.3	12.0±3.1	11.8±3.1	11.8±3.2	584
Swiss (%)	14,223 (85.0)	5,418 (83.8)	5,693 (81.2)	3,938 (78.7)	29,272 (83.1)	0
Mortality
All, n (%)	4,524 (27.1)	1,891 (29.2)	1,691 (24.1)	1,359 (27.2)	9,465 (26.9)
CLD, n (%)	164 (1.0)	150 (2.3)	142 (2.0)	156 (3.1)	612 (1.7)
Lung cancer, n (%)	95 (0.6)	104 (1.6)	121 (1.7)	236 (4.7)	556 (1.6)

Notes:

a The maximum number of missing values in an analysis was 2,027 (some individuals had missing values for multiple variables).

b Excluding 60 study participants with missing information on smoking status.

Abbreviations: BMI, body mass index; CLD, chronic lung disease.

Figure 1 Relative* risks of chronic lung disease (A) and lung cancer (B) of BMI categories by smoking status (hazard ratios with 95% CI).

Notes: *Reference population are normal weight (BMI 18.5 to ≤25 kg/m²) individuals who never smoked; adjusted for age, sex, survey, years of education, marital status, nationality, physical activity, alcohol consumption, and a diet proxy.
Abbreviations: BMI, body mass index; CLD, chronic lung disease; HR, hazard ratio.