Table IV.
Association between caffeine intake and the risk of NMSC in the Singapore Chinese Health Study (N = 61,321)
| Cancer | Cases | Person-years | Model 1* HR (95% CI) | Model 2† HR (95% CI) |
|---|---|---|---|---|
| All skin cancers | ||||
| Caffeine intake, mg/d | ||||
| 0 to <50 | 124 | 185,966 | 1.00 | 1.00 |
| 50 to <250 | 421 | 778,614 | 0.80 (0.66–0.98) | 0.81 (0.66–0.99) |
| 250 to <400 | 50 | 121,741 | 0.62 (0.45–0.87) | 0.63 (0.45–0.88) |
| ≥400 | 14 | 36,264 | 0.58 (0.33–1.01) | 0.59 (0.34–1.04) |
| P for trend | .0017 | .0025 | ||
| Basal cell carcinoma | ||||
| Caffeine intake, mg/d | ||||
| 0 to <50 | 87 | 185,224 | 1.00 | 1.00 |
| 50 to <250 | 299 | 775,848 | 0.84 (0.66–1.06) | 0.85 (0.67–1.08) |
| 250 to <400 | 30 | 121,359 | 0.57 (0.38–0.87) | 0.59 (0.39–0.90) |
| ≥400 | 11 | 36,217 | 0.70 (0.37–1.32) | 0.76 (0.40–1.42) |
| P for trend | .01 | .03 | ||
| Squamous cell carcinoma | ||||
| Caffeine intake, mg/d | ||||
| 0 to <50 | 37 | 184,620 | 1.00 | 1.00 |
| 50 to <250 | 122 | 773,586 | 0.73 (0.50–1.06) | 0.71 (0.49–1.03) |
| 250 to <400 | 20 | 121,234 | 0.71 (0.41–1.23) | 0.67 (0.38–1.17) |
| ≥400 | 3 | 36,072 | 0.35 (0.11–1.15) | 0.33 (0.10–1.07) |
| P for trend | .0498 | .03 | ||
CI, Confidence interval; HR, hazard ratio; NMSC, nonmelanoma skin cancer.
*
Model 1 is adjusted for age at recruitment, sex, dialect group, year of recruitment, and education.
†
Model 2 is adjusted for the variables in model 1 and body mass index; smoking; alcohol consumption; history of diabetes; and time spent sitting at work, watching television, engaging in moderate activity, engaging in strenuous sports, and engaging in vigorous activity.