Table 3.
Subgroup analyses for the relationship between dietary iron intake trajectory groups and risk of type 2 diabetes mellitus from fully-adjusted models
| Subgroups | No. of cases/No. of total participants | Mean iron intake, (mg/day) | Hazard ratio (95% CI) | P-for interaction | |
|---|---|---|---|---|---|
| By sex | 0.53 | ||||
| Females | 1 | 98/8,910 | 10.8 | Ref | |
| 2 | 76/8,341 | 12.3 | 0.87 (0.64, 1.20) | ||
| 3 | 64/11,136 | 14.0 | 0.53 (0.37, 0.75) | ||
| 4 | 49/6,477 | 17.4 | 0.81 (0.53, 1.25) | ||
| Males | 1 | 80/4,066 | 10.9 | Ref | |
| 2 | 71/4,721 | 12.3 | 0.77 (0.56, 1.08) | ||
| 3 | 119/8,678 | 14.2 | 0.71 (0.52, 0.98) | ||
| 4 | 120/8,786 | 17.8 | 0.69 (0.49, 0.98) | ||
| By age | 0.17 | ||||
| < 65 | 1 | 137/11,316 | 10.9 | Ref | |
| 2 | 118/11,157 | 12.3 | 0.88 (0.68, 1.14) | ||
| 3 | 128/16,593 | 14.1 | 0.60 (0.46, 0.78) | ||
| 4 | 123/12,678 | 17.7 | 0.69 (0.51, 0.94) | ||
| ≥ 65 | 1 | 41/1,660 | 10.9 | Ref | |
| 2 | 29/1,905 | 12.3 | 0.51 (0.30, 0.85) | ||
| 3 | 55/3,221 | 14.0 | 0.82 (0.52, 1.27) | ||
| 4 | 46/2,585 | 17.3 | 0.86 (0.51, 1.45) | ||
| By obesity | 0.04 | ||||
| With obesity | 1 | 111/2,551 | 10.8 | Ref | |
| 2 | 69/2,381 | 12.3 | 0.62 (0.45, 0.84) | ||
| 3 | 98/3,241 | 14.1 | 0.59 (0.44, 0.80) | ||
| 4 | 83/2,337 | 17.5 | 0.59 (0.42, 0.85) | ||
| Without obesity | 1 | 67/10,424 | 10.9 | Ref | |
| 2 | 78/10,681 | 12.3 | 1.09 (0.77, 1.52) | ||
| 3 | 85/16,573 | 14.1 | 0.67 (0.47, 0.96) | ||
| 4 | 86/12,926 | 17.6 | 0.84 (0.56, 1.25) | ||
| By CVD | < 0.01 | ||||
| With CVD | 1 | 46/1,314 | 10.8 | Ref | |
| 2 | 45/1,301 | 12.3 | 0.93 (0.60, 1.46) | ||
| 3 | 48/2,061 | 14.1 | 0.69 (0.43, 1.10) | ||
| 4 | 27/1,698 | 17.7 | 0.41 (0.23, 0.73) | ||
| Without CVD | 1 | 132/11,662 | 10.9 | Ref | |
| 2 | 102/11,761 | 12.3 | 0.75 (0.57, 0.97) | ||
| 3 | 135/17,753 | 14.0 | 0.62 (0.47, 0.81) | ||
| 4 | 142/13,565 | 17.6 | 0.80 (0.59, 1.08) | ||
| By hypercholesterolemia | 0.08 | ||||
| With hyper-cholesterolemia | 1 | 60/1,666 | 10.9 | Ref | |
| 2 | 62/1,774 | 12.3 | 0.90 (0.62, 1.31) | ||
| 3 | 69/2,671 | 14.2 | 0.78 (0.53, 1.15) | ||
| 4 | 58/2,152 | 17.7 | 0.62 (0.39, 0.97) | ||
|
Without hyper-cholesterolemia |
1 | 118/11,310 | 10.9 | Ref | |
| 2 | 85/11,288 | 12.3 | 0.70 (0.52, 0.93) | ||
| 3 | 114/17,143 | 14.1 | 0.56 (0.42, 0.75) | ||
| 4 | 111/13,111 | 17.6 | 0.70 (0.50, 0.97) | ||
| By hypertension | 0.16 | ||||
| With hypertension | 1 | 145/6,664 | 10.8 | Ref | |
| 2 | 117/6,857 | 12.4 | 0.78 (0.61, 1.00) | ||
| 3 | 151/10,627 | 14.0 | 0.63 (0.49, 0.82) | ||
| 4 | 139/8,237 | 17.5 | 0.72 (0.53, 0.96) | ||
| Without hypertension | 1 | 33/6,312 | 11.0 | Ref | |
| 2 | 30/6,205 | 12.2 | 0.87 (0.52, 1.47) | ||
| 3 | 32/9,187 | 14.1 | 0.53 (0.31, 0.91) | ||
| 4 | 30/7,026 | 17.7 | 0.56 (0.30, 1.06) | ||
CI, confidence interval; CVD, cardiovascular disease