Table 2.

Results of analyses associating lipid metabolites with VCI.

References	Statistical analysis	Covariates in fully adjusted model	Statistically significant	Key finding
Liu et al. (10)	Bonferroni correction; Random forests; Logistic regression model	Age, sex, diabetes, hypertension, current drinkers, dietary, and lipid-lowering drugs	1) Ceramides and sphingolipids: Cer species comprising short-chain fatty acyls (16–18C) and long chain fatty acids. 2) Phospholipids: PC PC (22:6/13:0), PC (36:6), PC(37:6), PC (38:3), PC (38:5), PC(38:6), PC (38:8), PC (39:3), PC (40:7), PC (40:8), PC (40:9), PC (42:7), PC (42:9), PC (42:10), PC (37:1), PC (38:1); PE PE (16:0/22:6), PE (18:0/22:6), PE (18:0p/22:6), PE (18:1p/22:6) and PE (20:0p/22:6) 3) Cholesterol esters and glycerolipids: ChE (16:0), ChE (17:0), ChE (18:1), ChE (18:1), ChE (20:3), ChE (20:4), and ChE (20:5); DG (12:0/20:5) and DG (18:0/18:0)	1) Ceramides and sphingolipids: The level of various Cer species were lower in plasma of VaD patients.SM species did not significantly differ between VaD patients and controls. 2) Phospholipids: VaD patients had higher levels of plasma LPC. LPC (22:6) showed a significantly higher level in VaD. Major phospholipids classes including PC, PE and PI showed a tendency to be lower in VaD patients compared to healthy controls. 3) Cholesterol esters and glycerolipids: Most ChEs showed lower abundance in VaD patients
Liu et al. (5)	Principal component analysis (PCA);partial least-squares discriminant analysis (PLS-DA);orthogonal partial least-squares discriminant analysis (OPLS-DA); unit variance (UV); logistic regression model	______	Carnitine, creatinine, glutamine, proline, N-acetylneuraminic acid, hypoxanthine, uric acid, tyrosine, kynurenine, phenylalanine, sphingosine-1-phosphate, and palmitoylcarnitine, citric acid, valine, isoleucine, tryptophan, and lysoPCs	(1)The serum samples of stroke patients exhibited higher levels of carnitine, creatinine, glutamine, proline, N-acetylneuraminic acid, hypoxanthine, uric acid, tyrosine, kynurenine, phenyl-alanine, sphingosine-1-phosphate, and palmitoylcarnitine in combination with lower levels of citric acid, valine, isoleucine, tryptophan and lysoPCs. (2) Sixteen differential metabolites were identified as potential markers for discriminating between the stroke patients with and without cognitive impairment. In contrast with the PSNCI group, the levels of carnitine, glutamine, uric acid, tyrosine, kynurenine, and phenylalanine were increased in the PSCI group, whereas the levels of valine, isoleucine, tryptophan, lysoPCs, palmitoylcarnitine, and stearoylcarnitine were markedly decreased. (3) Three serum metabolites [glutamine, kynurenine, and LysoPC(18:2)] were identified as candidate diagnostic biomarkers for PSCI, and their combined use yielded good diagnostic capacity for PSCI by receiver operating characteristic curves.
Zarrouk et al. (12)	Student's t-test; Bonferroni correction; Receiver operating characteristic curves (ROC); Spearman correlation	_______	Fatty acid profiles of red blood cells and plasma, including SFA (sum of saturated fatty acids), MUFA (sum of monounsaturated fatty acids), PUFA (sum of polyunsaturated fatty acids), OA (oleic acid), LA (linoleic acid), ALA (alpha linolenic acid), AA (arachidonic acid), EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid)	Significant variations of several SFAs, including VLCFAs; C26:0 could constitute a convenient peripheral blood biomarker of dementia, including AD.
Zhang et al. (13)	Student's t-test; Chi-square test; Logistic regression model; Pearson	_______	Lp-PLA2	The serum Lp-PLA2 in VD group were significantly higher than the non-dementia group, the Lp-PLA2 in VCIND group were significantly higher than the nomal cognition group. The result of Logistic regression showed that Lp-PLA2 was a significant risk factor of VD, and its level was negatively correlated with the score of cognitive function. The cutoff value of Lp-PLA2 between the VD and non-dementia was 164.65 ng/ml and was 120.8 ng/ml between the normal cognition group and VCIND group.
Niu et al. (14)	Logistic regression model; Spearman's correlation	_______	Lp-PLA2	Lp-PLA2 was the independent risk factors for cognitive impairment in ischemic CSVD patients. Serum levels of and Lp-PLA2 were significantly higher in moderate and severe CI groups than in mild CI group and in severe CI group than in moderate CI group and were positively related with the severity of CI in ischemic CSVD patients
Zhang et al. (15)	Student's t-test; Chi-square test; Logistic regression model	_______	Lp-PLA2 activity	The activity of Lp-PLA2 was significant higher in VCIND group compared to healthy controls. And the Lp-PLA2 activity increased as MoCA scores went down.
Hou et al. (16)	Student's t-test; Chi-square test; Logistic regression model	Age, sex, BMI, blood pressure, blood glucose, and blood fats	Lp-PLA2	Plasma Lp-PLA2 levels in AD group and VaD group were significantly higher than those in control group, and plasma Lp-PLA2 level in VaD group was significantly higher than that in AD group. The elevated plasma Lp-PLA2 level was associated with high risk of AD and VaD, and the correlation with VaD was greater than AD.
Bai et al. (17)	Student's t-test; Chi-square test	_______	Lp-PLA2	Plasma Lp-PLA2 levels was significant higher in VCIND group compared to controls.