Characteristics of the study participants by survey and diabetes status, the Tromsø Study 1994–2016
| Tromsø 4 1994–1995 | Tromsø 5 2001 | Tromsø 6 2007–2008 | Tromsø 7 2015–2016 | |||||||||
| People without diabetes | Known diabetes | Undiagnosed diabetes | People without diabetes | Known diabetes | Undiagnosed diabetes | People without diabetes | Known diabetes | Undiagnosed diabetes | People without diabetes | Known diabetes | Undiagnosed diabetes | |
| n | 6451 | 192 | 77 | 5386 | 273 | 172 | 11 103 | 610 | 274 | 18 755 | 1084 | 290 |
| Female | 3657 (56.7) | 97 (50.5) | 37 (48.1) | 3141 (58.3) | 150 (54.9) | 76 (44.2) | 5916 (53.3) | 291 (47.7) | 124 (45.3) | 9896 (52.8) | 445 (45.3) | 108 (37.2) |
| Male | 2794 (43.3) | 95 (49.5) | 40 (51.9) | 2245 (41.7) | 123 (45.1) | 96 (55.8) | 5187 (46.7) | 319 (52.3) | 150 (54.7) | 8859 (47.2) | 538 (54.7) | 182 (62.8) |
| Age groups | ||||||||||||
| 40–49 | 432 (6.7) | 4 (2.1) | 3 (3.9) | 313 (5.8) | 8 (2.9) | 2 (1.2) | 3344 (30.1) | 76 (12.5) | 22 (8.0) | 6019 (32.1) | 145 (14.7) | 37 (12.8) |
| 50–59 | 2562 (39.7) | 37 (19.3) | 16 (20.8) | 989 (18.4) | 27 (9.9) | 20 (11.6) | 2216 (20.0) | 97 (15.9) | 38 (13.9) | 5512 (29.4) | 222 (22.6) | 59 (20.3) |
| 60–69 | 2455 (38.1) | 88 (45.8) | 35 (45.5) | 2219 (41.2) | 108 (39.6) | 63 (36.6) | 3602 (32.4) | 255 (41.8) | 107 (39.1) | 4501 (24.0) | 324 (33.0) | 91 (31.4) |
| 70–79 | 987 (15.3) | 62 (32.3) | 21 (27.3) | 1654 (30.7) | 107 (39.2) | 77 (44.8) | 1534 (13.8) | 136 (22.3) | 77 (28.1) | 2186 (11.7) | 232 (23.6) | 75 (25.9) |
| 80–89 | 15 (0.2) | 1 (0.5) | 2 (2.6) | 211 (3.9) | 23 (8.4) | 10 (5.8) | 407 (3.7) | 46 (7.5) | 30 (10.9) | 537 (2.9) | 60 (6.1) | 28 (9.7) |
| Education | ||||||||||||
| Primary | 3343 (51.8) | 126 (65.6) | 54 (70.1) | 1609 (29.9) | 107 (39.2) | 65 (37.8) | 3122 (28.1) | 219 (35.9) | 127 (46.4) | 6365 (33.9) | 341 (34.7) | 121 (41.7) |
| Secondary | 1947 (30.2) | 52 (27.1) | 14 (18.2) | 2500 (46.4) | 116 (42.5) | 69 (40.1) | 3689 (33.2) | 208 (34.1) | 90 (32.8) | 8240 (43.9) | 291 (29.6) | 80 (27.6) |
| Tertiary | 1124 (17.4) | 13 (6.8) | 8 (10.4) | 1017 (18.9) | 35 (12.8) | 24 (14.0) | 4159 (37.5) | 168 (27.5) | 51 (18.6) | 4108 (21.9) | 325 (33.1) | 78 (26.9) |
| Income | ||||||||||||
| Low | – | – | – | – | – | – | 3873 (34.9) | 299 (49.0) | 156 (56.9) | 3773 (20.1) | 337 (34.3) | 95 (32.8) |
| Medium | – | – | – | – | – | – | 3685 (33.2) | 156 (25.6) | 66 (24.1) | 5215 (27.8) | 299 (30.4) | 94 (32.4) |
| High | – | – | – | – | – | – | 2728 (24.6) | 76 (12.5) | 26 (9.5) | 9097 (48.5) | 281 (28.6) | 77 (26.6) |
| BMI | ||||||||||||
| Mean | 25.9 | 28.7 | 29.0 | 26.6 | 29.0 | 29.4 | 26.7 | 29.3 | 30.1 | 27.1 | 29.9 | 31.4 |
| <25 | 2780 (43.1) | 45 (23.4) | 18 (23.4) | 1970 (36.6) | 60 (22.0) | 29 (16.9) | 4047 (36.4) | 120 (19.7) | 39 (14.2) | 6365 (33.9) | 146 (14.9) | 29 (10.0) |
| 25–29 | 2785 (43.2) | 80 (41.7) | 29 (37.7) | 2418 (44.9) | 98 (35.9) | 71 (41.3) | 5001 (45.0) | 239 (39.2) | 110 (40.1) | 8240 (43.9) | 398 (40.5) | 98 (33.8) |
| ≥30 | 873 (13.5) | 67 (34.9) | 30 (39.0) | 966 (17.9) | 112 (41.0) | 71 (41.3) | 2038 (18.4) | 249 (40.8) | 124 (45.3) | 4108 (21.9) | 432 (43.9) | 160 (55.2) |
Data are n (%). Education and household income are self-reported. Education categories, primary (primary and lower secondary education), secondary (high school or vocational school) and tertiary education (college and university level), missing data on education varied from 0.6% in Tromsø 4 to 5% in Tromsø 5. Income was divided in lower third, mid-third and upper third percentiles (<33, 33–66 and over 66). Data on income were not collected in Tromsø 4 and 5. In Tromsø 6 and 7, the proportion with missing data on income was 7.7% and 3.8%, respectively. Missing data for BMI were less than 0.6% in all surveys. Missing data were not imputed.
BMI, body mass index.