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

Table 3 The effects of sex × p-tau₁₈₁ 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	0.20*	-0.11	0.23*
Age	0.11	0.30*	0.26*	0.19*	0.17*	0.00	0.45*	0.13
Sex	0.18	0.14	0.07	-0.03	0.19	0.19	0.22*	0.02
APOE ɛ4 genotype	0.01	-0.08	-0.01	0.03	0.03	0.00	0.01	-0.01
Amyloid-β₄₂	-0.03	-0.01	-0.07	0.09	0.02	-0.07	-0.02	-0.06
P-tau₁₈₁	-0.01	-0.02	0.26*	0.02	0.09	0.04	0.05	0.27*
Sex x P-tau₁₈₁	0.01	-0.01	-0.08	-0.11	-0.16	0.08	-0.06	-0.08
Adjusted R²	0.06	0.12	0.13	0.08	0.03	0.07	0.27	0.11
B. AD
Age	0.04	0.22*	0.22*	0.16*	0.18*	-0.01	0.41*	0.10
Sex	0.16*	0.16*	0.04	-0.12	0.07	0.26*	0.22*	-0.02
Amyloid-β₄₂	0.08	0.01	0.02	-0.13	-0.01	-0.01	0.03	0.01
P-tau₁₈₁	0.10	0.02	0.34*	-0.09	0.08	0.03	0.07	0.34*
Sex x P-tau₁₈₁	-0.07	-0.06	-0.09	-0.04	-0.16	0.03	-0.08	-0.06
Adjusted R²	0.03	0.07	0.12	0.04	0.04	0.05	0.23	0.09
C. CU
Age	0.36*	0.46*	0.33*	0.18	0.11	0.05	0.49*	0.19
Sex	0.20	0.11	0.05	-0.09	0.15	0.12	0.14	0.02
Amyloid-β₄₂	0.05	-0.03	0.21	0.02	0.03	0.09	0.00	0.22
P-tau₁₈₁	-0.34	-0.21	0.27	0.12	-0.09	-0.08	-0.07	0.32
Sex x P-tau₁₈₁	0.12	0.05	-0.23	-0.28	0.09	0.08	0.08	-0.28
Adjusted R²	0.15	0.18	0.15	0.02	-0.01	-0.02	0.23	0.08

^*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, CU cognitively unimpaired, KA kynurenic acid, Kyn kynurenine, Pic picolinic acid, Trp trypthophan, QA quinolinic acid

ISSN: 1758-9193