Table 1.
Baseline characteristics of study subjects according to ABO blood type*
| Blood group |
||||
| Characteristic | O | A | AB | B |
| No. of subjects | ||||
| NHS | 33 258 | 27 514 | 6150 | 10 438 |
| HPFS | 12 962 | 11 153 | 2314 | 3714 |
| Total | 46 220 | 38 667 | 8464 | 14 152 |
| Age | ||||
| Median (years) | 62 | 62 | 64 | 62 |
| <60 years (%) | 38.8 | 40.0 | 32.6 | 40.4 |
| 60–69.9 years (%) | 38.9 | 38.2 | 39.8 | 38.6 |
| ≥70 years (%) | 22.2 | 21.8 | 27.6 | 21.0 |
| Female (%) | 72.0 | 71.1 | 72.7 | 73.8 |
| White (%) | 97.1 | 97.9 | 96.3 | 96.2 |
| BMI | ||||
| Median (kg/m2) | 25.8 | 25.7 | 25.6 | 25.7 |
| <25 kg/m2 (%) | 42.5 | 42.8 | 43.9 | 42.2 |
| 25–29.9 kg/m2 (%) | 37.8 | 38.0 | 37.3 | 38.2 |
| ≥30 kg/m2 (%) | 19.7 | 19.3 | 18.9 | 19.6 |
| Physical activity level | ||||
| Median (MET-h/wk) | 13.4 | 13.7 | 13.1 | 13.4 |
| <10 MET-h/wk (%) | 42.1 | 41.2 | 43.2 | 42.2 |
| 10–19.9 MET-h/wk (%) | 19.9 | 20.9 | 19.0 | 20.1 |
| ≥20 MET-h/wk (%) | 38.0 | 37.8 | 37.8 | 37.7 |
| Smoking status (%) | ||||
| Never | 45.0 | 46.2 | 44.5 | 45.0 |
| Past | 44.4 | 43.7 | 44.1 | 44.2 |
| Current | 10.6 | 10.2 | 11.3 | 10.8 |
| Diabetes mellitus (%) | 6.7 | 6.7 | 7.9 | 7.1 |
| Family history of pancreatic cancer (%)† | 2.5 | 2.5 | 3.0 | 2.9 |
*
NHS = Nurses’ Health Study; HPFS = Health Professionals Follow-up Study; BMI = body mass index; MET-h/wk = metabolic equivalent task hours per week.
†
History of pancreatic cancer in a participant's mother, father, or sibling; data available only for Nurses’ Health Study participants.