Table 3.
Pooled multivariable hazard ratios and 95% confidence intervals of squamous cell carcinoma by fat intake in the Nurses’ Health Study and Health Professionals Follow-up Study.
| Q1 | Q2 | Q3 | Q4 | Q5 | P trend | |
|---|---|---|---|---|---|---|
| Total fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 0.92 (0.83, 1.03) | 1.07 (0.94, 1.21) | 1.02 (0.92, 1.13) | 1.03 (0.92, 1.15) | 0.20 |
| Saturated fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 1.07 (0.97, 1.17) | 1.04 (0.94, 1.15) | 1.07 (0.96, 1.19) | 0.98 (0.88, 1.09) | 0.99 |
| HR2b (95% CI) | 1.00 (referent) | 1.13 (1.01, 1.25) | 1.13 (1.00, 1.27) | 1.18 (1.03, 1.34) | 1.11 (0.96, 1.30) | 0.11 |
| Monounsaturated fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 0.96 (0.87, 1.07) | 1.01 (0.92, 1.12) | 0.97 (0.88, 1.08) | 1.02 (0.92, 1.13) | 0.63 |
| HR2b (95% CI) | 1.00 (referent) | 0.90 (0.80, 1.02) | 0.92 (0.81, 1.04) | 0.87 (0.75, 1.00) | 0.91 (0.77, 1.07) | 0.37 |
| Cholesterol | ||||||
| HR1a (95% CI) | 1.00 (referent) | 0.96 (0.88, 1.06) | 0.93 (0.85, 1.03) | 0.96 (0.87, 1.05) | 0.82 (0.73, 0.93) | 0.002 |
| HR2b (95% CI) | 1.00 (referent) | 0.94 (0.86, 1.04) | 0.91 (0.83, 1.01) | 0.92 (0.83, 1.03) | 0.80 (0.67, 0.94) | 0.001 |
| Polyunsaturated fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 1.04 (0.94, 1.15) | 1.08 (0.97, 1.19) | 1.09 (0.99, 1.21) | 1.16 (1.05, 1.28) | 0.001 |
| HR2b (95% CI) | 1.00 (referent) | 1.06 (0.96, 1.18) | 1.11 (1.00, 1.24) | 1.13 (1.01, 1.27) | 1.20 (1.07, 1.36) | 0.001 |
| Omega-6 fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 1.02 (0.88, 1.17) | 1.08 (0.97, 1.19) | 1.11 (1.00, 1.23) | 1.18 (1.06, 1.30) | 0.0001 |
| HR2b (95% CI) | 1.00 (referent) | 1.04 (0.89, 1.21) | 1.11 (1.00, 1.25) | 1.16 (1.03, 1.31) | 1.23 (1.08, 1.41) | 0.0005 |
| Omega-3 fat | ||||||
| HR1a (95% CI) | 1.00 (referent) | 0.99 (0.90, 1.10) | 1.04 (0.94, 1.15) | 1.02 (0.93, 1.13) | 1.04 (0.94, 1.15) | 0.36 |
| HR2b (95% CI) | 1.00 (referent) | 0.98 (0.88, 1.08) | 1.01 (0.91, 1.12) | 0.98 (0.88, 1.09) | 0.97 (0.87, 1.10) | 0.78 |
HRs, hazard ratios; Cis, confidence intervals; NHS, Nurses’ Health Study; HPFS, Health Professionals Follow-up Study
The multivariate-adjusted hazard ratios from each cohort were pooled using random effects model.
Multivariable model 1 was jointly stratified by age in months and calendar year of the questionnaire cycle and adjusted for family history of melanoma, natural hair color, number of arm moles, sunburn susceptibility as a child/adolescent, number of lifetime blistering sunburns, cumulative UV flux since baseline, body mass index, physical activity, smoking status, incident melanoma, incident BCC, personal history of non-skin cancer, intakes of total energy, alcohol, caffeine and citrus fruits. Among women analyses were additionally adjusted for menopausal status and postmenopausal hormone use.
Multivariable model 2 was adjusted for the same covariates as multivariable model 1 and for other fats in quintiles simultaneously. Saturated, polyunsaturated, and monounsaturated fats and cholesterol were adjusted for each other. Omega-6 fat and omega-3 fat were adjusted for each other, as well as adjustment for saturated, monounsaturated fats, and for cholesterol.