Table 4.
ORs (95% CIs) of colorectal cancer ranked by quartile of serum carnitine and betaine
| OR (95% CI) by quartile of serum biomarker (µmol/L) | ||||||
|---|---|---|---|---|---|---|
| Carnitine | N | 1 (≤29.8) | 2 (>29.8 to 33.5) | 3 (>33.5 to 38.3) | 4 (>38.3) | P trend |
| Colorectal cancer | ||||||
| No. cases/ No. controls |
644/644 | 157/161 | 151/161 | 178/161 | 158/161 | |
| Age and batch adjusted | 644/644 | 1.00 (Ref.) | 0.97 (0.70–1.35) | 1.15 (0.83–1.59) | 1.02 (0.73–1.43) | 0.74 |
| Fully adjusteda | 642/643 | 1.00 (Ref.) | 0.97 (0.70–1.35) | 1.15 (0.83–1.59) | 1.03 (0.73–1.44) | 0.71 |
| Cancer of the Proximal Colon | ||||||
| No. cases/ No. controls |
169/169 | 38/50 | 42/46 | 50/34 | 39/39 | |
| Age and batch adjusted | 169/169 | 1.00 (Ref.) | 1.34 (0.70–2.59) | 2.22 (1.13–4.36) | 1.44 (0.72–2.87) | 0.16 |
| Fully adjusteda | 169/169 | 1.00 (Ref.) | 1.33 (0.69–2.58) | 2.21 (1.12–4.34) | 1.42 (0.71–2.84) | 0.17 |
| Cancer of the Distal Colon | ||||||
| No. cases/ No. controls |
153/153 | 42/36 | 25/42 | 46/41 | 40/34 | |
| Age and batch adjusted | 153/153 | 1.00 (Ref.) | 0.49 (0.24–1.00) | 0.96 (0.49–1.89) | 1.05 (0.50–2.20) | 0.60 |
| Fully adjusteda | 152/153 | 1.00 (Ref.) | 0.49 (0.24–1.02) | 0.97 (0.49–1.90) | 1.06 (0.51–2.22) | 0.60 |
| Cancer of the Rectum | ||||||
| No. cases/ No. controls |
282/282 | 69/66 | 73/62 | 70/77 | 70/77 | |
| Age and batch adjusted | 282/282 | 1.00 (Ref.) | 1.12 (0.67–1.85) | 0.85 (0.51–1.41) | 0.84 (0.51–1.40) | 0.37 |
| Fully adjusteda | 281/281 | 1.00 (Ref.) | 1.15 (0.69–1.91) | 0.84 (0.51–1.41) | 0.85 (0.51–1.41) | 0.37 |
| Betaine | N | 1 (≤24.75) |
2 (>24.75 to 30.62) |
3 (>30.62 to 37.56) |
4 (>37.56) |
P trend |
| Colorectal cancer | ||||||
| No. cases/ No. controls |
644/644 | 152/161 | 169/161 | 154/161 | 169/161 | |
| Age and batch adjusted | 644/644 | 1.00 (Ref.) | 1.12 (0.82–1.54) | 1.02 (0.74–1.41) | 1.13 (0.82–1.56) | 0.58 |
| Fully adjusteda | 642/643 | 1.00 (Ref.) | 1.12 (0.82–1.53) | 1.02 (0.74–1.40) | 1.12 (0.81–1.55) | 0.61 |
|
Cancer of the Proximal Colon |
||||||
| No. cases/ No. controls |
169/169 | 40/49 | 41/31 | 43/45 | 45/44 | |
| Age and batch adjusted | 169/169 | 1.00 (Ref.) | 1.68 (0.87–3.23) | 1.20 (0.64–2.25) | 1.33 (0.69–2.53) | 0.62 |
| Fully adjusteda | 169/169 | 1.00 (Ref.) | 1.71 (0.88–3.30) | 1.24 (0.66–2.33) | 1.34 (0.70–2.57) | 0.60 |
|
Cancer of the Distal Colon |
||||||
| No. cases/ No. controls |
153/153 | 38/37 | 41/40 | 34/40 | 40/36 | |
| Age and batch adjusted | 153/153 | 1.00 (Ref.) | 1.00 (0.52–1.92) | 0.81 (0.41–1.58) | 1.11 (0.57–2.18) | 0.83 |
| Fully adjusteda | 152/153 | 1.00 (Ref.) | 1.00 (0.52–1.93) | 0.79 (0.40–1.57) | 1.17 (0.59–2.31) | 0.73 |
| Rectal Cancer | ||||||
| No. cases/ No. controls |
282/282 | 62/60 | 81/78 | 68/67 | 71/71 | |
| Age and batch adjusted | 282/282 | 1.00 (Ref.) | 1.12 (0.69–1.82) | 1.09 (0.66–1.81) | 1.08 (0.65–1.80) | 0.86 |
| Fully adjusteda | 281/281 | 1.00 (Ref.) | 1.10 (0.68–1.78) | 1.05 (0.63–1.75) | 1.02 (0.61–1.71) | 0.98 |
Logistic regression models adjusted for batch (categorical, 27 batches) and age (continuous). Quartiles of serum carnitine were based on the distribution among controls. Medians for each quartile (based on controls) were used in trend test; medians for carnitine quartiles 1 through 4 were 26.4, 31.9, 35.5 and 41.1, respectively; medians for betaine quartiles 1 through 4 were 24.75, 30.62 and 37.56, respectively.
P<0.0001
P<0.001
Model additionally adjusted for the number of years smoked regularly (continuous), number of cigarettes smoked per day (continuous), education (college graduate, some college or technical school, versus ≤ high school), body mass index (continuous, kg/m2), heavy physical activity in leisure (yes/no), heavy occupational physical activity (yes/no), physical activity frequency (≥3 times per week, versus <3), total energy intake (continuous, kcal/day)