Sex-specific associations of kynurenic acid with neopterin in Alzheimer’s disease

Table 2 The effects of sex × Aβ₄₂ on tryptophan, KP metabolites and the KA/QA ratio

	Trp	Kyn	KA	AA	3-HK	Pic	QA	KA/QA
A. Whole cohort
Diagnoses	-0.12	-0.02	0.18*	-0.25*	-0.01	0.2*	-0.11	0.23*
Age	0.10	0.30*	0.26*	0.20*	0.17*	0.01	0.45*	0.13
Sex	0.20	0.08	0.01	-0.16	0.08	0.19	0.21	-0.04
APOE ɛ4 genotype	0.01	-0.08	-0.01	0.03	0.04	-0.01	0.01	-0.00
Amyloid-β₄₂	-0.02	-0.05	-0.09	0.04	-0.00	-0.09	-0.01	-0.08
P-tau₁₈₁	-0.00	-0.03	0.22*	-0.04	0.00	0.08	0.02	0.23*
Sex x Amyloid-β₄₂	-0.02	0.09	0.02	0.08	0.01	0.06	-0.04	0.02
Adjusted R²	0.06	0.12	0.13	0.08	0.02	0.07	0.27	0.1
B. AD
Age	0.04	0.22*	0.22*	0.16*	0.19*	-0.01	0.42*	0.10
Sex	0.16	0.16	0.05	-0.12	0.07	0.26*	0.22*	-0.02
Amyloid-β₄₂	0.07	0.05	0.04	-0.16	-0.00	-0.03	-0.01	0.04
P-tau₁₈₁	0.07	-0.02	0.29*	-0.11	-0.00	0.04	0.04	0.30*
Sex x Amyloid-β₄₂	0.03	-0.04	-0.01	0.06	0.03	0.01	0.07	-0.02
Adjusted R²	0.02	0.07	0.12	0.04	0.03	0.05	0.23	0.09
C. CU
Age	0.36*	0.46*	0.35*	0.19	0.12	0.06	0.49*	0.21
Sex	0.20	0.11	0.04	-0.09	0.15	0.12	0.14	0.02
Amyloid-β₄₂	0.00	-0.05	0.41*	0.19	0.13	0.17	-0.01	0.48*
P-tau₁₈₁	-0.24	-0.17	0.10	-0.09	-0.01	-0.01	-0.00	0.11
Sex x Amyloid-β₄₂	0.07	0.03	-0.30	-0.26	-0.14	-0.10	0.01	-0.37
Adjusted R²	0.15	0.18	0.17	0.02	-0.00	-0.02	0.23	0.11

^*P < .01. significant associations in bold. Standardized β-coefficients are presented. Diagnoses: CU controls = 0, AD = 1; APOE ɛ4 genotype: neg = 0, pos = 1; Whole cohort (A): Amyloid-β₄₂ and P-tau₁₈₁ dichotomized according to laboratory-specific cut-off values: normal = 1, pathological = 2; AD patients (B) and CU controls (C): Amyloid-β₄₂ and P-tau₁₈₁ as continuous variables. Abbreviations: 3-HK 3-hydroxykynurenine, AA anthranilic acid, AD Alzheimer’s disease, APOE apolipoprotein E, CU cognitively unimpaired, KA kynurenic acid, Kyn kynurenine, Pic picolinic acid, Trp trypthophan, QA quinolinic acid

ISSN: 1758-9193