Table 2.
Odds ratios for incident Alzheimer’s disease by quintiles of intake of folate, vitamin B-12, and vitamin B-6 among 1,041 persons after 4.0 years of follow-up, Chicago Health and Aging Project, 1993–2002
| Quintiles of intake | P for Trend* |
|||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | ||
| Total folate | ||||||
| Median µg/d | 202.8 | 275.2 | 338.2 | 474.5 | 752.7 | |
| Incident Cases (%) | 11.5 | 9.1 | 15.6 | 12.1 | 6.8 | |
| Odds Ratio (95% Confidence lnterval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 0.7 (0.3, 1.8) | 1.4 (0.5, 3.7) | 1.2 (0.5, 2.8) | 0.5 (0.2, 1.2) | 0.12 |
| Basic-Adjusteda | 1.0 (referent) | 0.9 (0.4, 2.1) | 1.7 (0.6, 4.4) | 1.8 (0.7, 4.6) | 0.7 (0.3, 1.7) | 0.47 |
| Basic-and Nutrient-Adjustedb | 1.0 (referent) | 1.0 (0.4, 2.3) | 1.9 (0.7, 5.0) | 2.7 (1.0, 7.1) | 1.6 (0.5, 5.2) | 0.21 |
| Folate in food | ||||||
| Median µg/d | 184.0 | 240.2 | 279.6 | 330.3 | 405.2 | |
| Incident Cases (%) | 11.0 | 12.6 | 8.8 | 11.8 | 10.7 | |
| Odds Ratio (95% Confidence Interval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 1.3 (0.5, 3.4) | 0.7 (0.2, 2.0) | 1.1 (0.4, 2.7) | 0.8 (0.4, 1.7) | 0.55 |
| Basic-Adjusteda | 1.0 (referent) | 1.5 (0.6, 4.0) | 0.8 (0.3, 2.2) | 1.3 (0.5, 3.2) | 1.2 (0.5, 2.5) | 0.84 |
| Basic- and Nutrient-Adjustedb | 1.0 (referent) | 1.7 (0.7, 4.1) | 0.9 (0.4, 2.4) | 1.5 (0.6, 3.5) | 1.8 (0.8, 4.1) | 0.29 |
| Total Vitamin B-12 | ||||||
| Median µg/d | 3.1 | 5.3 | 7.8 | 12.7 | 20.6 | |
| Incident Cases (%) | 14.1 | 13.0 | 6.6 | 15.2 | 6.1 | |
| Odds Ratio (95% Confidence Interval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 1.0 (0.4, 3.0) | 0.5 (0.2, 1.1) | 1.2 (0.5, 3.0) | 0.4 (0.2, 1.0) | 0.12 |
| Basic-Adjusteda | 1.0 (referent) | 1.0 (0.4, 2.6) | 0.5 (0.2, 1.3) | 1.4 (0.6, 3.3) | 0.4 (0.2, 1.1) | 0.20 |
| Basic- and Nutrient-Adjustedb | 1.0 (referent) | 1.0 (0.4, 2.7) | 0.6 (0.3, 1.5) | 1.7 (0.7, 4.4) | 0.6 (0.2, 1.6) | 0.67 |
| Vitamin B-12 in food | ||||||
| Median µg/d | 2.5 | 4.2 | 5.6 | 7.7 | 14.0 | |
| Incident Cases (%) | 11.5 | 12.3 | 9.0 | 12.8 | 9.4 | |
| Odds Ratio (95% Confidence lnterval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 1.1 (0.5, 2.4) | 0.8 (0.3, 2.2) | 1.1 (0.4, 3.0) | 0.8 (0.3, 2.4) | 0.66 |
| Basic-Adjusteda | 1.0 (referent) | 1.0 (0.4, 3.0) | 0.4 (0.2, 1.1) | 1.2 (0.5, 3.0) | 0.4 (0.2, 1.0) | 0.73 |
| Basic- and Nutrient-Adjustedb | 1.0 (referent) | 1.4 (0.7, 2.7) | 0.8 (0.3, 2.3) | 1.5 (0.6, 4.0) | 1.0 (0.3, 2.7) | 0.87 |
| Total vitamin B-6 | ||||||
| Median mg/d | 1.2 | 1.6 | 1.9 | 3.1 | 5.5 | |
| Incident Cases (%) | 14.0 | 12.6 | 12.1 | 11.6 | 4.9 | |
| Odds Ratio (95% Confidence Interval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 0.8 (0.3, 1.9) | 0.8 (0.4, 1.7) | 0.9 (0.3, 2.2) | 0.3 (0.1, 0.6) | 0.002 |
| Basic-Adjusteda | 1.0 (referent) | 1.2 (0.5, 2.5) | 0.6 (0.3, 1.4) | 1.1 (0.4, 3.0) | 0.4 (0.2, 0.8) | 0.02 |
| Basic- and Nutrient-Adjustedb | 1.0 (referent) | 0.9 (0.4, 2.1) | 1.3 (0.6, 3.1) | 1.9 (0.7, 5.1) | 0.7 (0.2, 2.4) | 0.80 |
| Vitamin B-6 in food | ||||||
| Median mg/d | 1.2 | 1.4 | 1.6 | 1.9 | 2.2 | |
| Incident Cases (%) | 14.4 | 8.9 | 15.7 | 10.7 | 5.3 | |
| Odds Ratio (95% Confidence Interval) | ||||||
| Age-Adjusted** | 1.0 (referent) | 0.6 (0.2, 1.3) | 1.2 (0.5, 2.5) | 0.6 (0.3, 1.4) | 0.3 (0.2, 0.6) | 0.005 |
| Basic-Adjusteda | 1.0 (referent) | 0.7 (0.3, 1.6) | 1.3 (0.6, 2.8) | 0.8 (0.4, 2.0) | 0.4 (0.2, 0.8) | 0.10 |
| Basic- and Nutrient-Adjustedb | 1.0 (referent) | 0.7 (0.3, 1.7) | 1.6 (0.8, 3.4) | 1.0 (0.4, 2.3) | 0.7 (0.3, 1.4) | 0.66 |
P-value for linear trend is based on logistic regression models with the nutrient variable modeled as a continuous variable with persons in each quintile assigned the median value for that quintile.
Age-adjusted models include terms for age (years), time period of observation (years), and indicator variables for quintiles of nutrient intake.
Basic-adjusted models include terms from the age-adjusted model plus sex, race (black/white), education (years), APOE-ε4 (any ε4 versus none), an interaction term between race and APOE-ε4, and frequency of participation in cognitive activities.
Basic-and Nutrient-Adjusted models include terms from the basic model plus intake of vitamin E from food sources (mg/d) and total intake of niacin (mg/d).