Table 2.
Regression coefficients (95% CI) for cognitive function by quartiles of iron related dietary pattern among Chinese adults aged ≥55 years old attending China Health and Nutrition Survey (N = 4852) between 1997 and 2006
| Dietary pattern quartiles | |||||
|---|---|---|---|---|---|
| Q1 (low intake) | Q2 | Q3 | Q4 (high intake) | p for trend | |
| Global cognitive function | Coef. (95% CI) | ||||
| Model 1a | 0.00 | −0.06 (−0.42–0.30) | −0.53 (−0.92--0.15) | −1.23 (−1.65--0.81) | < 0.001 |
| Model 2b | 0.00 | 0.00 (− 0.39–0.38) | − 0.32 (− 0.73–0.08) | − 0.74 (−1.19--0.28) | < 0.001 |
| Model 3c | 0.00 | − 0.11 (− 0.50–0.28) | − 0.42 (− 0.84–0.00) | − 0.79 (− 1.25--0.32) | < 0.001 |
| Model 3+ carbohydrate (quartiles) | 0.00 | 0.15 (− 0.26–0.55) | 0.05 (− 0.40–0.50) | − 0.19 (− 0.70–0.32) | 0.373 |
| Model 3 + lead (quartiles) | 0.00 | −0.01 (− 0.45–0.42) | −0.24 (− 0.74–0.27) | −0.57 (− 1.16–0.02) | 0.035 |
| Model 3 + iron (quartiles) | 0.00 | 0.05 (−0.37–0.47) | −0.16 (− 0.63–0.31) | −0.41 (− 0.95–0.13) | 0.080 |
| Sensitivity analysis d | 0.00 | 0.01 (− 0.36–0.38) | −0.30 (− 0.69–0.09) | −0.52 (− 0.96--0.09) | 0.006 |
| Verbal memory score | |||||
| Model 1a | 0.00 | −0.13 (− 0.38–0.13) | −0.44 (− 0.71--0.17) | −0.71 (− 1.00--0.41) | < 0.001 |
| Model 2b | 0.00 | −0.09 (− 0.37–0.18) | −0.25 (− 0.55–0.04) | −0.33 (− 0.66--0.01) | 0.026 |
| Model 3c | 0.00 | −0.15 (− 0.43–0.13) | −0.31 (− 0.61--0.02) | −0.37 (− 0.70--0.04) | 0.020 |
| Model 3+ carbohydrate (quartiles) | 0.00 | 0.01 (−0.29–0.30) | − 0.07 (− 0.39–0.26) | −0.10 (− 0.47–0.26) | 0.509 |
| Model 3 + lead (quartiles) | 0.00 | −0.09 (− 0.41–0.22) | −0.17 (− 0.54–0.19) | −0.19 (− 0.61–0.24) | 0.376 |
| Model 3 + iron (quartiles) | 0.00 | −0.01 (− 0.31–0.29) | −0.09 (− 0.42–0.25) | −0.06 (− 0.45–0.33) | 0.688 |
| Sensitivity analysisd | 0.00 | −0.10 (− 0.38–0.17) | −0.23 (− 0.52–0.06) | −0.22 (− 0.55–0.10) | 0.131 |
Regression coefficients and 95% CI were estimated with mixed effect regression models with different levels of adjustment
a Model 1 adjusted for age, gender and energy intake
b Model 2 further adjusted for intake of fat, smoking, alcohol drinking, income, urbanicity, education, and physical activity
c Model 3 further adjusted for BMI and hypertension
d Sensitivity analysis model 3 further adjusted for diabetes and stroke after excluding those with a global cognitive function score ≤ 4
All the adjusted variables are treated as time-varying covariates. Bold font represents p<0.05