Background
Methods
Study design and participants
Measurement and categorization of sedentary behavior
Measurement of type 2 diabetes
Confounding variables
Statistical analysis
Results
All participants (n = 3942) | Participants who developed type 2 diabetes (n = 91) | Participants who did not develop type 2 diabetes (n = 3851) | P value for diabetes vs. non-diabetes | |
---|---|---|---|---|
Sex | 0.06 | |||
Male | 1738 (44.1) | 49 (53.9) | 1689 (43.9) | |
Female | 2204 (55.9) | 42 (46.1) | 2162 (56.1) | |
Missing | 0 | 0 | 0 | |
Ethnicity | 0.39 | |||
White | 2953 (74.9) | 66 (72.5) | 2887 (75.0) | |
Other | 115 (2.9) | 1 (1.1) | 114 (3.0) | |
Missing | 874 (22.2) | 24 (26.4) | 850 (22.1) | |
BMI category | < 0.0001 | |||
Not overweight | 1900 (48.2) | 21 (23.1) | 1879 (48.8) | |
Overweight | 247 (6.3) | 19 (20.9) | 228 (5.9) | |
Obese | 43 (1.1) | 6 (6.6) | 37 (1.0) | |
Missing | 1752 (44.4) | 45 (49.5) | 1707 (44.3) | |
Parental education | 0.02 | |||
No qualifications | 518 (13.1) | 20 (22.0) | 498 (12.9) | |
O-levels | 953 (24.2) | 15 (16.5) | 938 (24.4) | |
A-levels | 268 (6.8) | 9 (9.9) | 259 (6.7) | |
Degree or higher | 879 (22.3) | 14 (15.4) | 865 (22.5) | |
Missing | 1324 (33.6) | 33 (36.3) | 1291 (33.5) | |
Smoking status | 0.15 | |||
Non-smoker | 2212 (56.1) | 49 (53.9) | 2163 (56.2) | |
Occasional smoker | 1005 (25.5) | 19 (20.9) | 986 (25.6) | |
Smoker | 682 (17.3) | 23 (25.3) | 659 (17.1) | |
Missing | 43 (1.1) | 0 | 43 (1.1) | |
Fruit consumption | 0.04 | |||
0–1 times/week | 451 (11.4) | 18 (19.8) | 433 (11.2) | |
2–3 times/week | 890 (22.6) | 26 (28.6) | 864 (22.4) | |
4–5 times/week | 871 (22.1) | 15 (16.5) | 856 (22.2) | |
6–7 times/week | 1090 (27.7) | 21 (23.1) | 1069 (27.8) | |
Missing | 640 (16.2) | 11 (1.7) | 629 (16.3) | |
Sugary beverage consumption | 0.02 | |||
None | 676 (17.2) | 9 (9.9) | 667 (17.3) | |
1–2 glasses/day | 1224 (31.1) | 41 (45.1) | 1183 (30.7) | |
3–4 glasses/ day | 680 (17.3) | 18 (19.8) | 662 (17.2) | |
> 4 glasses/day | 595 (15.1) | 11 (12.1) | 584 (15.2) | |
Missing | 767 (19.5) | 12 (13.2) | 755 (19.6) | |
Takeaway consumption | 0.11 | |||
None | 1545 (39.2) | 34 (37.4) | 1511 (39.2) | |
1 time/week | 1456 (36.9) | 28 (30.8) | 1428 (37.1) | |
> 2 times/week | 747 (19.0) | 26 (28.6) | 721 (18.7) | |
Missing | 194 (4.9) | 3 (3.3) | 191 (5.0) | |
Physical activity at age 16 | 0.65 | |||
Quartile 1 | 864 (21.9) | 22 (24.2) | 842 (21.9) | |
Quartile 2 | 1019 (25.9) | 19 (20.9) | 1000 (26.0) | |
Quartile 3 | 1037 (26.3) | 23 (25.3) | 1014 (26.3) | |
Quartile 4 | 1022 (25.9) | 27 (29.7) | 995 (25.8) |
N | Person-years of follow-up | Number of cases of type 2 diabetes | Type 2 diabetes cases/10,000 person-years | Hazard ratio (95% confidence interval) for type 2 diabetes | |||
---|---|---|---|---|---|---|---|
Model 1 | Model 2 | Model 3 | |||||
Watching TV and videos | |||||||
≤ 120 min/day | 1857 | 49,910 | 36 | 7 | 1 | 1 | 1 |
121–240 min/day | 1404 | 38,012 | 27 | 7 | 0.99 (0.60, 1.63) | 0.89 (0.54, 1.47) | 0.89 (0.54, 1.47) |
> 240 min/day | 681 | 17,768 | 28 | 16 | 2.31 (1.41, 3.78)* | 2.01 (1.22, 3.32)* | 2.06 (1.24, 3.43)* |
Computer | |||||||
None | 3606 | 96,920 | 80 | 8 | 1 | 1 | 1 |
1–30 min/day | 197 | 5128 | 6 | 12 | 1.43 (0.63, 3.29) | 1.20 (0.52, 2.81) | 1.21 (0.52, 2.84) |
> 30 min/day | 139 | 3642 | 5 | 14 | 1.71 (0.69, 4.22) | 1.26 (0.50, 3.16) | 1.11 (0.44, 2.80) |
Total screen time | |||||||
≤ 120 min/day | 1821 | 48,950 | 36 | 7 | 1 | 1 | 1 |
121–240 min/day | 1385 | 37,478 | 25 | 7 | 0.91 (0.55, 1.52) | 0.83 (0.50, 1.39) | 0.83 (0.49, 1.38) |
> 240 min/day | 736 | 19,262 | 30 | 16 | 2.23 (1.37, 3.62)* | 1.85 (1.13, 3.04)* | 1.86 (1.13, 3.06)* |
N | Person-years of follow-up | Number of cases of type 2 diabetes | Type 2 diabetes cases/10,000 person-years | Hazard ratio (95% confidence interval) for type 2 diabetes | |||
---|---|---|---|---|---|---|---|
Model 1 | Model 2 | Model 3 | |||||
Homework | |||||||
None | 2512 | 67,060 | 59 | 9 | 1 | 1 | 1 |
1–30 min/day | 373 | 10,022 | 9 | 9 | 1.01 (0.50, 2.04) | 1.12 (0.55, 2.26) | 1.13 (0.56, 2.31) |
> 30 min/day | 1057 | 28,608 | 23 | 8 | 0.89 (0.55, 1.44) | 1.05 (0.65, 1.72) | 1.13 (0.67, 1.86) |
Reading | |||||||
None | 2246 | 59,986 | 47 | 8 | 1 | 1 | 1 |
1–30 min/day | 1082 | 29,148 | 30 | 10 | 1.30 (0.82, 2.05) | 1.39 (0.87, 2.20) | 1.39 (0.87, 2.22) |
> 30 min/day | 614 | 16,556 | 14 | 8 | 1.07 (0.59, 1.94) | 1.15 (0.63, 2.10) | 1.13 (0.62, 2.07) |
Reading and doing homework | |||||||
None | 1479 | 39,220 | 31 | 8 | 1 | 1 | 1 |
1–120 min/day | 1643 | 44,338 | 43 | 10 | 1.20 (0.75, 1.90) | 1.34 (0.84, 2.14) | 1.37 (0.86, 2.19) |
> 120 min/day | 820 | 22,132 | 17 | 8 | 0.94 (0.52, 1.70) | 1.16 (0.64, 2.12) | 1.24 (0.68, 2.27) |