Current Smoking is a Risk Factor for the Irregular Surface and Calcification of Carotid Plaque in Men

Figures & data

Table 1 Baseline Characteristics of Subjects Classified According to Smoking Status

Demographics	Never-Smoker (n=79)	Current Smoker (n=144)	Former Smoker (n=94)	P-value
Age (years)	68±9	64±8	68±8	<0.001
BMI (kg/m^2)	25.0±2.	24.7±3.0	25.2±2.9	0.541
Systolic blood pressure (mm Hg)	133.1±14.6	133.3±13.2	136.9±13.9	0.092
Diastolic blood pressure (mm Hg)	77.2±8.8	76.8±8.5	79.6±8.8	0.054
Total cholesterol (mg/dL)	3.6±1.1	3.5±0.8	3.4±0.8	0.298
HDL-cholesterol (mg/dL)	1.3±0.3	1.2±0.4	1.3±0.3	0.974
LDL-cholesterol (mg/dL)	2.1±0.9	2.0±0.7	2.1±0.7	0.944
Triglyceride (mg/dL)	1.9±1.0	1.6±1.1	1.4±0.6	0.031
Glycemia (mmol/L)	6.2±2.2	6.5±2.5	5.8±1.9	0.069
Diabetes mellitus	32/47	57/87	33/61	0.718
Hypertension	56/23	99/45	68/26	0.833
Dyslipidemia	30/49	43/101	33/61	0.433
Smoking duration (years)	0	38±9	27±12	<0.001
Daily smoking amount	0	20.6±11.1	18.5±11.8	<0.001

Figure 1 Image of irregular surface and calcification of carotid plaque for enrolled smokers and non-smokers, including CT scanning (left panel) and ultrasonography (right panel).

Table 2 Carotid Plaque Characteristics According to Smoking Status

Plaque Parameters	Never-Smoker (n=79)	Current Smoker (n=144)	Former Smoker (n=94)	P-value
Echogenicity				0.244
Homogeneous	2	0	2
Mainly high	6	17	6
Mainly medium	50	88	52
Mainly low	21	39	34
Thickness (mm)	5.8±1.4	5.7±1.3	5.9±1.2	0.833
Surface morphology				0.004
Regular	26	21	26
Irregular	53	123	68
Presence of calcification	59	139	84	<0.001

Figure 2 Ridge trace analysis for different examination strategies. (A) Gold standard for plaque diagnosis. (B) Ultrasonography for determination of calcified plaque.

Figure 3 Analysis of plaque scores and age index, which were verified by ultrasonography index. X axis, age index; Y axis, scores for calcification and other plaque morphology. *P<0.05, **P<0.01.

Table 3 Related Risk Factors Between Calcification and Plaque Surface Morphology

	Presence of Calcification			Surface Morphology
	P value	OR	CI 95%	P value	OR	CI 95%
Age	0.08	1.04	0.99–1.09	0.02	1.04	1.0–1.07
BMI	0.28	0.93	0.82–1.06	0.14	1.08	0.98–1.18
Hypertension	0.43	0.07	0.29–1.69	0.73	1.11	0.61–2.02
Hyperlipidemia	0.76	0.89	0.40–1.96	0.48	1.24	0.68–2.25
Hyperglycemia	0.13	1.91	0.83–4.41	0.67	0.89	0.50–1.56
Current smoking	0.02	3.74	1.2–11.6	0.00	2.81	1.43–5.53
Former smoking	0.01	0.336	0.14–0.78	0.52	0.81	0.40–1.57