Table 2.

Levels of metabolites differentially expressed in participants by diagnostic group.

	NCI	MCI	AD
Brain samples
GLCA %, median [IQR]	0.44 [0.24, 0.84]	0.59 [0.25, 1.22]	0.86 [0.42, 1.24]*
DCA/CA, median [IQR]	6.06 [2.57, 11.79]	9.14 [6.00, 15.75]	8.60 [4.26, 31.96]*
Petroselinic acid, median [IQR]	1696.67 [1,323.38, 2,166.37]	1856.55 [1,529.43, 2,374.30]	2,181.55 [1,761.35, 2,617.07]**
Linoleic acid, median [IQR]	13.86 [10.64, 18.15]	14.37 [10.40, 21.62]	19.93 [15.08, 29.43]***
Myristic acid, median [IQR]	164.14 [130.79, 205.57]	177.10 [136.34, 205.38]	206.86 [177.15, 246.65]**
Palmitic acid, median [IQR]	8,504.53 [6,898.86, 10,496.19]	9,025.76 [7,811.72, 10,964.45]	10,323.59 [9,204.13, 12,785.95]***
Palmitoleic acid, median [IQR]	64.96 [48.13, 79.72]	75.39 [61.45, 100.90]	82.06 [64.21, 127.76]**

	NCI	MCI/AD
Serum samples
GLCA %, median [IQR]	0.96 [0.49, 1.60]	1.10 [0.54, 1.94]
DCA/CA, median [IQR]	10.30 [3.11, 28.10]	14.78 [3.69, 44.75]#
Petroselinic acid, median [IQR]	0.84 [0.45, 1.41]	0.49 [0.33, 1.02]###
Linoleic acid, median [IQR]	0.90 [0.64, 1.24]	0.73 [0.58, 0.99]##
Myristic acid, median [IQR]	0.84 [0.59, 1.22]	0.63 [0.52, 0.97]###
Palmitic acid, median [IQR]	0.89 [0.68, 1.18]	0.78 [0.62, 1.00]##
Palmitoleic acid, median [IQR]	0.75 [0.35, 1.35]	0.43 [0.23, 0.87]###

*P-value < 0.05, **P-value < 0.01, ***P-value < 0.001, by Wilcoxon rank sum test comparing AD vs. NCI.

^#P-value < 0.05, ^##P-value < 0.01, ^###P-value < 0.001, by Wilcoxon rank sum test comparing MCI/AD vs. NCI.

NCI cognitively normal, MCI mild cognitive impairment, AD Alzheimer’s disease, IQR interquartile range.