Table 2. Relative risks of colorectal adenoma among women in the Nurses' Health Study II, 1991-2007, by categories of calcium.
| Calcium (mg/ day) | RR and (95% CI) by Category | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| <=500 | 501-600 | 601-700 | 701-800 | 801-1000 | 1001-1250 | 1251-1500 | 1501-6000 | P trend₪ | |
| Adenoma≠ | |||||||||
| #Ca/ #Co | 61/926 | 104/1,629 | 176/2,674 | 212/3,463 | 483/7,808 | 521/9,207 | 362/6,648 | 354/6,775 | |
| Age Adjusted RR† | 1.32(1.00-1.73) | 1.23(0.99-1.33) | 1.25(1.05-1.50) | 1.15(0.97-1.35) | 1.12(0.99-1.27) | 1.00 | 0.95(0.83-1.09) | 0.90(0.79-1.04) | <0.001 |
| Multivariable RR§ | 1.21(0.90-1.61) | 1.14(0.91-1.43) | 1.18(0.98-1.41) | 1.09(0.92-1.29) | 1.09(0.96-1.24) | 1.00 | 0.98(0.85-1.12) | 0.99(0.85-1.14) | 0.03 |
| Proximal colon | |||||||||
| #Ca/ #Co | 24/926 | 40/1,629 | 67/2,674 | 89/3,463 | 209/7,808 | 250/9,207 | 156/6,648 | 173/6,775 | |
| Age Adjusted RR† | 1.19(0.78-1.83) | 1.06(0.76-1.49) | 1.06(0.80-1.39) | 1.06(0.83-1.35) | 1.03(0.86-1.24) | 1.00 | 0.85(0.69-1.04) | 0.90(0.74-1.10) | 0.03 |
| Multivariable RR§ | 1.07(0.69-1.68) | 0.97(0.68-1.38) | 0.98(0.74-1.31) | 1.00(0.77-1.28) | 1.00(0.83-1.21) | 1.00 | 0.87(0.71-1.07) | 1.00(0.81-1.23) | 0.71 |
| Distal colon | |||||||||
| #Ca/ #Co | 36/926 | 50/1,629 | 89/2,674 | 106/3,463 | 249/7,808 | 243/9,207 | 181/6,648 | 152/6,775 | |
| Age Adjusted RR† | 1.56(1.09-2.24) | 1.21(0.89-1.65) | 1.31(1.02-1.67) | 1.19(0.94-1.50) | 1.22(1.02-1.46) | 1.00 | 1.02(0.84-1.25) | 0.84(0.68-1.03) | <0.001 |
| Multivariable RR§ | 1.39(0.95-2.03) | 1.10(0.80-1.51) | 1.21(0.94-1.56) | 1.11(0.88-1.41) | 1.18(0.99-1.42) | 1.00 | 1.06(0.87-1.29) | 0.94(0.76-1.16) | 0.03 |
| Rectum | |||||||||
| #Ca/ #Co | 14/926 | 20/1,629 | 33/2,674 | 43/3,463 | 79/7,808 | 86/9,207 | 61/6,648 | 62/6,775 | |
| Age Adjusted RR† | 1.78(1.00-3.16) | 1.40(0.86-2.29) | 1.40(0.93-2.09) | 1.36(0.96-2.01) | 1.10(0.81-1.50) | 1.00 | 0.97(0.70-1.35) | 0.96(0.69-1.33) | 0.007 |
| Multivariable RR§ | 1.68(0.92-3.06) | 1.36(0.82-2.26) | 1.37(0.91-2.08) | 1.37(0.94-2.00) | 1.10(0.81-1.50) | 1.00 | 0.97(0.69-1.35) | 0.99(0.70-1.39) | 0.04 |
Adenoma found in proximal and/or distal colon and/or rectum
Odds ratio and 95% confidence interval from age (5 yr cats) and time period (2 yr study period intervals) adjusted logistic regression
Odds ratio and 95% confidence interval from logistic regression with adjustment for the following covariates: age, family history of colorectal cancer (first degree relative), reason for endoscopy (screening vs. symptoms), height (inches), BMI (quintiles), physical activity (METs-hrs//wk in quintiles), pack years of smoking, aspirin use (never, past, current 1 dy/wk, current 2-3 dys/wk, current 4-5 dys/wk, current >=6 dys/wk), UV-B flux (Robertson-Berger meter units in quintiles), energy adjusted intakes of folate (mcg/dy), vitamin B6 (mg/dy), alcohol (gm in cats: 0, >0 to <5, 5 to <15, and >=15/dy), unprocessed red meat (servings/d), and processed meats (servings/d)
Calculated using median intakes of calcium