Comparison between ORs of skin SCC and quartiles of RBC fatty acids among participants in the Southeastern Arizona Health Study by inclusion of all controls (OR1) and only those without history of prior actinic keratoses (OR2)
| Level of fatty acid* | P for trend | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1st quartile | 2nd quartile | 3rd quartile | 4th quartile | |||||||||
| Saturated fatty acids | ||||||||||||
| 16:00 | OR1 | 1.00 | 0.59 (0.36-0.96) | 0.68 (0.42-1.10) | 0.46 (0.26-0.82) | 0.003 | ||||||
| OR2 | 1.00 | 0.92 (0.56-1.51) | 0.61 (0.36-1.04) | 0.34 (0.18-0.64) | ||||||||
| 18:00 | OR1 | 1.00 | 1.01 (0.51-1.99) | 1.04 (0.51-2.12) | 0.96 (0.45-2.03) | 0.311 | ||||||
| OR2 | 1.00 | 1.05 (0.52-2.14) | 1.13 (0.54-2.38) | 1.20 (0.55-2.65) | ||||||||
| Monounsaturated fatty acids | ||||||||||||
| 16:1n-7 | OR1 | 1.00 | 0.82 (0.49-1.36) | 0.70 (0.42-1.18) | 0.51 (0.30-0.89) | 0.066 | ||||||
| OR2 | 1.00 | 1.03(0.60-1.76) | 0.84 (0.48-1.46) | 0.78 (0.44-1.39) | ||||||||
| 18:1n-7c | OR1 | 1.00 | 0.67 (0.33-1.35) | 0.34 (0.15-0.79) | 0.34 (0.14-0.78) | 0.042 | ||||||
| OR2 | 1.00 | 0.67 (0.33-1.36) | 0.32 (0.14-0.76) | 0.24 (0.10-0.57) | ||||||||
| 18:1n-9c | OR1 | 1.00 | 1.42 (0.88-2.27) | 0.73 (0.41-1.30) | 0.91 (0.45-1.85) | 0.278 | ||||||
| OR2 | 1.00 | 1.25 (0.73-2.12) | 0.95 (0.53-1.70) | 0.92 (0.44-1.91) | ||||||||
| 18:1n-9t | OR1 | 1.00 | 1.19 (0.70-2.03) | 0.91 (0.55-1.49) | 0.87 (0.53-1.44) | 0.286 | ||||||
| OR2 | 1.00 | 1.05 (0.60-1.85) | 0.65 (0.36-1.17) | 0.64 (0.36-1.12) | ||||||||
| Polyunsaturated fatty acids | ||||||||||||
| 18:2n-6c | OR1 | 1.00 | 1.07 (0.65-1.76) | 1.36 (0.83-2.25) | 0.96 (0.55-1.66) | 0.735 | ||||||
| OR2 | 1.00 | 1.00 (0.59-1.69) | 1.39 (0.82-2.38) | 0.99 (0.56-1.75) | ||||||||
| 18:2n-6t | OR1 | 1.00 | 0.45 (0.27-0.76) | — | — | 0.003 | ||||||
| OR2 | 1.00 | 0.71 (0.42-1.19) | — | — | 0.780 | |||||||
| 18:3n-3 | OR1 | 0.753 | ||||||||||
| OR2 | 1.00 | 1.28 (0.87-1.89) | — | — | ||||||||
| 20:2n-9 | OR1 | 1.00 | 1.47 (0.87-2.49) | 1.30 (0.77-2.20) | 1.26 (0.74-2.13) | 0.560 | ||||||
| OR2 | 1.00 | 1.64 (0.95-2.83) | 1.43 (0.84-2.45) | 1.03 (0.61-1.74) | ||||||||
| 20:3n-9 | OR1 | 1.00 | 1.31 (0.78-2.21) | 0.88 (0.51-1.50) | 1.45 (0.88-2.39) | 0.450 | ||||||
| OR2 | 1.00 | 1.24 (0.72-2.13) | 0.83 (0.48-1.43) | 1.96 (1.12-3.42) | ||||||||
| 20:4n-6 | OR1 | 1.00 | 0.98 (0.58-1.64) | 1.09 (0.65-1.85) | 1.52 (0.91-2.52) | 0.001 | ||||||
| OR2 | 1.00 | 1.61 (0.92-2.80) | 1.40 (0.79-2.49) | 2.38 (1.37-4.12) | ||||||||
| Long-chain N-3 polyunsaturated fatty acids | ||||||||||||
| 20:5n-3 | OR1 | 1.00 | 1.60 (0.94-2.73) | 1.60 (0.95-2.70) | 1.22 (0.72-2.08) | 0.448 | ||||||
| OR2 | 1.00 | 1.87 (1.07-3.24) | 2.28 (1.31-3.95) | 1.54 (0.91-2.60) | ||||||||
| 22:6n-3 | OR1 | 1.00 | 1.61 (0.96-2.72) | 1.66 (0.97-2.86) | 1.71 (0.99-2.94) | 0.726 | ||||||
| OR2 | 1.00 | 1.37 (0.80-2.33) | 1.61 (0.92-2.81) | 1.17(0.67-2.05) | ||||||||
| P/S ratio | OR1 | 1.00 | 1.55 (1.02-2.36) | 1.19 (0.71-1.99) | 1.94 (1.02-3.66) | 0.020 | ||||||
| OR2 | 1.00 | 1.56 (0.92-2.63) | 1.89 (1.11-3.21) | 1.28 (0.76-2.17) | ||||||||
| N3/N6 ratio | OR1 | 1.00 | 1.45 (0.85-2.47) | 1.38 (0.80-2.39) | 1.28 (0.73-2.25) | 0.731 | ||||||
| OR2 | 1.00 | 1.53 (0.88-2.64) | 1.45 (0.82-2.56) | 1.32 (0.74-2.35) | ||||||||
NOTE: OR1 is OR adjusted for age, sex, lab, tanning ability, freckles, history of actinic keratosis and includes all cases and controls (n = 657). OR2 is OR adjusted for age, sex, lab, tanning ability, freckles and excludes 94 controls with history of prior actinic keratosis (n = 563).
↵* Quartiles defined by control group (all controls for OR1 and controls without AK for OR2); for 18:2n6t and 18:3n3 groups were categorized as detectable or not.