Table 3 Results of Spearman correlation analysis between baseline characteristics

CMV IgG

Age

0.19

0.017*

Education

− 0.17

0.036*

Flu vaccine uptake

0.278

0.001**

JHFRAT score

0.219

0.006**

MMSE score

−0.197

0.013*

Usage of hypnotic agents

0.169

0.043*

CD19⁺ B cell count

−0.179

0.026*

Chlamydia pneumoniae IgG

0.194

0.015*

Lymphocyte count

Age

−0.291

< 0.001***

Female Gender

0.226

0.004**

Body mass index

0.296

< 0.001***

Flu vaccine uptake

−0.192

0.017*

Smoking history

−0.194

0.014*

Diabetes mellitus

0.18

0.024*

JHFRAT

−0.225

0.004**

MMSE score

0.227

0.004**

MUST score

−0.259

0.001**

White blood cell count

0.5

< 0.001***

Hemoglobin

0.261

0.001**

Platelet count

0.185

0.018*

CD3⁺ T cell count

0.862

< 0.001***

CD4⁺ T cell count

0.757

< 0.001***

CD8⁺ T cell count

0.632

< 0.001***

CD19⁺ B cell count

0.449

< 0.001***

Albumin

0.297

< 0.001***

Cholesterol

0.319

< 0.001***

Triglyceride

0.177

0.024*

LDL-C

0.234

0.003**

hs-CRP

−0.186

0.018*

CD3⁺ T cell count

Age

−0.337

< 0.001***

Female Gender

0.304

< 0.001***

Body mass index

0.328

< 0.001***

Flu vaccine uptake

−0.209

0.01*

Diabetes mellitus

0.195

0.015*

JHFRAT score

−0.168

0.035*

MMSE score

0.193

0.015*

MUST score

−0.224

0.005

White blood cell count

0.401

< 0.001***

Hemoglobin

0.263

0.001**

Platelet count

0.17

0.032*

Lymphocyte count

0.862

< 0.001***

CD4⁺ T cell count

0.835

< 0.001***

CD8⁺ T cell count

0.792

< 0.001***

CD19⁺ B cell count

0.423

< 0.001***

Albumin

0.239

0.003**

Cholesterol

0.364

< 0.001***

LDL-C

0.281

< 0.001***

Triglyceride

0.206

0.01*

Chlamydia pneumoniae IgG

−0.17

0.033*

CD19⁺ B cell count

Age

−0.471

< 0.001***

Female gender

0.337

< 0.001***

Body mass index

0.265

0.001**

Flu vaccine uptake

−0.278

0.001**

Alcohol consumption

0.215

0.007**

Chronic liver disease

0.184

0.02*

Barthel index score

0.23

0.004**

MMSE score

0.24

0.002**

White blood cell count

0.202

0.011*

Hemoglobin

0.232

0.003**

Lymphocyte count

0.449

< 0.001***

CD3⁺ T cell count

0.423

< 0.001***

CD4⁺ T cell count

0.587

< 0.001***

CD4⁺/CD8⁺

0.343

< 0.001***

Albumin

0.192

0.016*

Cholesterol

0.299

< 0.001***

LDL-C

0.258

0.001**

Creatinine

−0.168

0.035*

CMV IgG

−0.179

0.026*