Table 5. Univariable and Multivariable-Adjusted Regression Analyses of Correlation between Normalized Whole-Brain GMV and TMT Scores in Participants Stratified by Age (<65 vs. ≥65 years).

Model I: Multivariable analysis adjusted for sex and age. Model II: Model I + diabetes mellitus, estimated glomerular filtration rate, and education. Model III: Model II + systolic blood pressure, smoking habits, drinking habits, hemoglobin, previous history of cardiovascular disease, and log-transformed urinary protein to creatinine ratio. Abbreviation: GMV, gray matter volume; TMT, Trail Making Test.

		TMT-A		TMT-B		ΔTMT
		Age <65 years (n = 51)	Age ≥65 years (n = 44)	Age <65 years (n = 51)	Age ≥65 years (n = 44)	Age <65 years (n = 51)	Age ≥65 years (n = 44)
Univariable analysis	Standardized β	- 0.256	- 0.500	- 0.389	- 0.472	- 0.398	- 0.412
	P	0.070	<0.001	0.005	0.001	0.004	0.006
	P for interaction	0.112		0.404		0.644
Model I	Standardized β	- 0.291	- 0.422	- 0.346	- 0.462	- 0.331	- 0.427
	P	0.097	0.004	0.040	0.003	0.048	0.009
	P for interaction	0.115		0.386		0.615
Model II	Standardized β	0.018	- 0.419	- 0.200	- 0.484	- 0.259	- 0.455
	P	0.933	0.006	0.315	0.002	0.195	0.005
	P for interaction	0.053		0.221		0.418
Model III	Standardized β	0.079	- 0.397	- 0.153	- 0.370	- 0.221	- 0.321
	P	0.729	0.041	0.467	0.054	0.287	0.101
	P for interaction	0.066		0.254		0.462