Table 3.
Type 3 test of multivariate-adjusted interaction effects for cognitive decline between green tea intake and HbA1c groups at each cut-off point of HbA1c level among 1,304 older Japanese adultsa
| Wald χ2 | P valueb | |
|---|---|---|
| Cut-off point of HbA1c 5.6% | ||
| Green tea intakec × HbA1c groupsd | 0.355 | 0.551 |
| Green tea intakec | 2.625 | 0.105 |
| HbA1c groupsd | 1.803 | 0.179 |
| Cut-off point of HbA1c 6.0% | ||
| Green tea intakec × HbA1c groupsd | 6.237 | 0.013 |
| Green tea intakec | 7.593 | <0.01 |
| HbA1c groupsd | 7.733 | <0.01 |
| Cut-off point of HbA1c 6.5% | ||
| Green tea intakec × HbA1c groupsd | 0.655 | 0.418 |
| Green tea intakec | 3.042 | 0.081 |
| HbA1c groupsd | 1.609 | 0.205 |
Abbreviations: HbA1c; glycosylated hemoglobin A1c (National Glycohemoglobin Standardization Program value).
a Cox proportional hazard model was used with adjusting for age, sex, body mass index, smoking, total physical activity, education, medical history of hypertension and dyslipidemia (considered separately), total energy intake, alcohol intake, intake of green and yellow vegetables, fish intake, and MMSE scores at baseline.
b Significance level adjusted by Bonferroni’s correction: P<0.017.
c Categories: < once a day, once a day, 2–3 times a day, and ≥4 times a day.
d Lower or higher groups of HbA1c levels were assigned for each of the three cut-off points.