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

Table 4 The effects of sex × neopterin on tryptophan, KP metabolites and the KA/QA ratio

	Trp	Kyn	KA	AA	3-HK	Pic	QA	KA/QA
A. Whole cohort
Diagnoses	-0.09	0.12	0.28*	-0.23*	0.05	0.22*	0.01	0.30*
Age	0.06	0.15*	0.17*	0.17*	0.11	-0.02	0.32*	0.08
Sex	0.18*	0.15*	0.03	-0.10	0.09	0.24*	0.19*	-0.02
APOE ɛ4 genotype	0.01	-0.09	-0.03	0.04	0.04	-0.01	0.00	-0.02
Amyloid-β₄₂	-0.02	0.02	-0.06	0.08	0.01	-0.06	0.00	-0.06
P-tau₁₈₁	-0.02	-0.10	0.17*	-0.05	-0.03	0.07	-0.05	0.20*
Neopterin (log10)	0.07	0.47*	0.39*	0.08	0.20*	0.05	0.40*	0.30*
Neopterin x sex	0.09	0.00	-0.16	-0.05	-0.01	0.05	0.01	-0.19*
Adjusted R²	0.07	0.29	0.20	0.08	0.05	0.07	0.39	0.14
B. AD
Age	0.02	0.08	0.12	0.12	0.14	-0.03	0.30*	0.03
Sex	0.16*	0.14*	0.01	-0.13	0.05	0.27*	0.20*	-0.06
Amyloid-β₄₂	0.09	-0.03	0.00	-0.13	0.00	-0.03	0.00	-0.01
P-tau₁₈₁	0.04	-0.13	0.20*	-0.15	-0.05	0.03	-0.07	0.24*
Neopterin (log10)	0.09	0.50*	0.48*	0.16	0.23*	0.02	0.44*	0.37*
Neopterin x sex	0.00	-0.05	-0.22*	-0.04	-0.05	0.07	-0.07	-0.23*
Adjusted R²	0.03	0.26	0.24	0.06	0.05	0.06	0.36	0.15
C. CU
Age	0.22	0.25*	0.31*	0.21	-0.08	0.00	0.29*	0.22
Sex	0.11	-0.16	0.12	-0.15	0.15	0.14	0.14	0.11
Amyloid-β₄₂	0.04	-0.04	0.20	0.00	0.02	0.09	-0.01	0.21
P-tau₁₈₁	-0.24*	-0.17	0.08	-0.11	-0.02	-0.01	0.00	0.09
Neopterin (log10)	0.00	0.34	0.16	-0.15	0.21	0.09	0.24	0.13
Neopterin x sex	0.31	0.10	-0.13	0.09	0.20	0.02	0.22	-0.23
Adjusted R²	0.21	0.31	0.13	-0.01	0.10	-0.02	0.37	0.06

^*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