Table 1 Baseline characteristics comparisons between IPN group and No IPN group of the 85 participants

General conditions and Comorbid conditions

Age (year)

68.48 ± 8.78

70.17 ± 9.06

67.24 ± 8.45

Male sex, n (%)

63 (74.1%)

27 (75%)

36 (73.5%)

Hypertension, n (%)

60 (70.6%)

27 (75%)

33 (67.3%)

Diabetes mellitus, n (%)

26 (30.6%)

14 (38.9%)

12 (24.5%)

Cerebral infraction, n (%)

21 (24.7%)

7 (19.4%)

14 (28.6%)

Coronary heart disease, n (%)

38 (44.7%)

17 (47.2%)

21 (42.9%)

Smoking history, n (%)

20 (23.5%)

6 (16.7%)

14 (28.6%)

Statin therapy, n (%)

79 (92.9%)

33 (91.7%)

46 (93.9%)

Serum lipid

Lp(a) (mg/L) *

184 (96.5–370)

260 (92–427.75)

173 (100–258.5)

TC (mmol/L)

4.49 ± 1.21

4.44 ± 1.10

4.53 ± 1.29

TG (mmol/L) *

1.34 (1.04–1.99)

1.44 (1.08–2.26)

1.23 (0.87–1.66)

LDL-C (mmol/L)

2.92 ± 0.91

2.88 ± 0.81

2.95 ± 0.99

LDL-C^(F) (mmol/L)

2.13 ± 0.75

2.07 ± 0.64

2.17 ± 0.82

HDL-C (mmol/L) *

0.99 (0.87–1.16)

0.98 (0.83–1.16)

1.02 (0.88–1.15)

Apo(a) (mmol/L)*

1.16 (1.01–1.28)

1.13 (1.00–1.25)

1.16 (1.02–1.30)

Apo(b) (mmol/L)*

0.79 (0.64–1.01)

0.77 (0.63–0.94)

0.80 (0.64–1.04)

Carotid plaque

Maximum ICA plaque thickness (mm)

3.89 ± 1.14

4.27 ± 0.90

3.61 ± 1.22

Total maximum ICA plaque thickness (mm)

6.59 ± 2.12

7.28 ± 1.84

6.08 ± 2.19

Degree of carotid stenosis

Mild, n (%)

27 (31.8%)

11 (30.6%)

16 (32.7%)

Moderate, n (%)

14 (16.5%)

6 (16.7%)

8 (16.3%)

Severe, n (%)

28 (32.9%)

14 (38.9%)

14 (28.6%)

Occlusion, n (%)

16 (18.8%)

5 (13.9%)

11 (22.4%)

Reasons for referral

Cardiovascular ischemia-related, n (%)

44 (51.8%)

22 (66.1%)

22 (44.9%)

Cerebral ischemia-related, n (%)

30 (35.3%)

11 (30.6%)

19 (38.8%)

Asymptomatic, n (%)

7 (8.2%)

2 (5.6%)

5 (10.2%)

Other

4 (4.7%)

1 (2.8%)

3 (6.1%)