Body mass index and its association with 22 cancer types: a Norwegian cohort study of 481 202 cancer cases

Figures & data

Figure 1. Forest plots illustrating hazard ratios (HR) and corresponding 95% confidence intervals (CI) for the risk of Gastrointestinal cancers across different age groups, considering both sexes combined (a), men (B), and women (C). each plot demonstrates the effect of a 5 kg/m² increase in body-mass index (BMI) on cancer risk, with BMI modelled as a linear variable. The number of cancer cases are indicated within brackets. Age 16-29 was at time of BMI measurement.

▪ Both sexes.

• Men.

♦ Women.

Figure 2. Forest plots illustrating hazard ratios (HR) and corresponding 95% confidence intervals (CI) for the risk of Gender specific cancers across different age groups. The plot demonstrates the effect of a 5 kg/m² increase in body-mass index (BMI) on cancer risk, with BMI modelled as a linear variable. The number of cancer cases are indicated within brackets. Age 16-29 was at time of BMI measurement.

• Men.

♦ Women.

Figure 3. Forest plots illustrating hazard ratios (HR) and corresponding 95% confidence intervals (CI) for the risk of other cancers across different age groups, considering both sexes combined (A), men (B), and women (C). Each plot demonstrates the effect of a 5 kg/m² increase in body-mass index (BMI) on cancer risk, with BMI modelled as a linear variable. The number of cancer cases are indicated within brackets. Age 16–29 was at time of BMI measurement.

▪ Both sexes.

• Men.

♦ Women.

Table 1. Characteristics of the study cohort from the Norwegian tuberculosis screening program 1963–1975.

	Men	Women	Both sexes
Study Cohort	829 081 (48.1%)	894 611 (51.9%)	1 723 692
Age at measurement* (years), Mean (SD)	43.2 (16.5)	43.1 (16.5)	43.2 (16.5)
Age group 1 (16–29)	216 228 (26.1%)	234 892 (26.3%)	451 120 (26.1%)
Height (cm), Mean (SD)	175.2 (6.3)	162.5 (5.8)	168.6 (8.8)
Weight (kg), Mean (SD)	74.8 (10.6)	65.6 (11.4)	70.1 (11.9)
BMI** (kg/m^2) Mean (SD)	24.4 (3.2)	24.9 (4.4)	24.6 (3.9)
BMI categories***
Underweight (BMI 15–18.5)	12 297 (1.5%)	23 817 (2.7%)	36 114 (2.1%)
Normal (18.5–25)	494 357 (59.6%)	494 551 (55.2%)	988 908 (57.4%)
Overweight (25–30)	282 710 (34.1%)	262 828 (29.4%)	545 538 (31.6%)
Obese (>30)	39 717 (4.8%)	113 415 (12.7%)	153 132 (8.9%)
Years of follow up****, Mean (SD)	30.9 (15.2)	33.8 (14.2)	32.4 (14.8)
Deceased at end of study ^† (%)	247 615 (29.9%)	149 997 (16.7%)	397 612 (23.1%)

All values are N (%) unless otherwise stated.

*Initial BMI measurement.

**Body Mass Index.

***WHO classification.

****Follow-up from BMI registration to cancer diagnoses.

^†Individuals deceased before age 75 at end of study (December 31st, 2018).

Data availability statement

Aggregated anonymous data may be available upon request and approval of Regional Committees for Medical and Health Research Ethics.