Table 5. Associations between APOE ε2 and IQ score measures.
| Association between APOE ε4 and the given IQ measure | ||||||
|---|---|---|---|---|---|---|
| Median (Min, Q1, Q3, Max) | Single variable analysis | Multivariable analysis | ||||
| IQ measure | ε2 allele not present (N = 519) | ε2 allele present (N = 88) | Regression coefficient (95% CI) | P-value | Regression coefficient (95% CI) | P-value |
| Full Scale IQ Score | 112 (72, 100, 120, 152) | 114 (76, 104, 122, 134) | 1.16 (-2.27, 4.58) | 0.51 | 0.03 (-2.41, 2.48) | 0.98 |
| Verbal Comprehension Index (VCI) | 110 (65, 100, 120, 140) | 110 (65, 98, 120, 130) | -0.03 (-3.53, 3.47) | 0.99 | -0.70 (-3.33, 1.94) | 0.60 |
| Working Memory Index (WMI) | 110 (60, 95, 115, 140) | 110 (65, 100, 115, 140) | 0.68 (-2.85, 4.21) | 0.70 | -0.11 (-2.75, 2.53) | 0.93 |
| Processing Speed Index (PSI) | 110 (55, 100, 125, 145) | 115 (80, 105, 125, 145) | 3.00 (-0.48, 6.49) | 0.091 | 1.85 (-1.56, 5.25) | 0.29 |
| Perceptual Reasoning Index (PRI) | 110 (65, 95, 120, 145) | 110 (70, 95, 120, 135) | 0.16 (-3.42, 3.73) | 0.93 | -0.80 (-4.14, 2.53) | 0.64 |
Regression coefficients, 95% CIs, and p values were calculated from linear regression models. Regression coefficients are interpreted as the difference in means of the given IQ measure between carriers and non-carriers of the ε2 allele (i.e. ε2 allele present vs. ε2 allele not present). A regression coefficient greater than “0” indicates a higher value of the given measure for ε2 carriers, and a regression coefficient less than “0” indicates a lower value of the given measure for ε2 carriers. Multivariable models were adjusted for school (Xiamen University or AnFang College), age, gender, height, weight, BMI, personality, smoking, drinking alcohol, physical exercise, and sleep quality. P values of 0.01 or lower were considered as statistically significant after applying a Bonferroni correction for multiple testing. Min = Minimum; Q1 = first quartile; Q3 = third quartile; Max = Maximum; CI = confidence interval.