Association between the MetS and angiographically determined coronary atherosclerosis
Significant CAD at angiography was present in 564 patients (55.8%); its prevalence was higher in patients with MetS than in subjects without MetS (59.5 vs. 52.8%; P = 0.034); adjustment for age, sex, LDL cholesterol, smoking, cardiovascular medications (statins, aspirin, ACE inhibitors/angiotensin receptor blocking agents and β-blocking agents), and CRP confirmed this result, with an odds ratio (OR) of 1.49 (95% CI 1.12–1.98; P = 0.007) for MetS patients.
The low HDL cholesterol (OR 1.57 [95% CI 1.11–2.22]; P = 0.011) and the high-glucose traits (1.33 [1.02–1.73]; P = 0.038) proved significantly and independently of the above covariates associated with significant CAD, whereas high triglycerides (P = 0.082), large waist (P = 0.826), and high blood pressure criteria (P = 0.145) were not independently associated with significant CAD.
CRP, MetS, and CAD
CRP was significantly higher in patients with MetS than in subjects without MetS (0.46 ± 0.62 vs. 0.35 ± 0.49 mg/dl; P < 0.001). In contrast, CRP did not differ significantly between patients with significant CAD and subjects without significant CAD (0.40 ± 0.59 vs. 0.39 ± 0.52 mg/dl; P = 0.706). CRP also was similar in subjects with any atherosclerotic lesion at angiography compared with subjects with completely normal coronary arteries (0.41 ± 0.57 vs. 0.36 ± 0.50 mg/dl; P = 0.325). Furthermore, CRP was not associated with significant CAD in a multivariate model adjusting for age, sex, LDL cholesterol, smoking, cardiovascular medications, and presence of MetS (standardized adjusted OR 0.97 [95% CI 0.76–1.25]; P = 0.822).
Considering both MetS and significant CAD, CRP was significantly higher in patients with MetS, both among those without significant CAD (0.45 ± 0.50 vs. 0.36 ± 0.53 mg/dl; P < 0.001) and among those with significant CAD (0.47 ± 0.69 vs. 0.34 ± 0.45; P = 0.001). In contrast, CRP did not differ between patients with significant CAD and those without significant CAD among subjects without MetS (P = 0.869) or among subjects with MetS (P = 0.411).
ANCOVA, adjusting for age, sex, LDL cholesterol, smoking, and cardiovascular medications, confirmed that MetS (F = 11.74; P = 0.001) but not significant CAD (F = 0.01; P = 0.983) was significantly associated with CRP.
Associations of individual MetS components with CRP
Univariately, serum CRP was significantly higher in patients who fulfilled the large waist (P < 0.001), the low HDL cholesterol (P < 0.001), the high blood pressure (P = 0.016), and the high glucose (P < 0.001) criteria but not in patients who fulfilled the high triglyceride criterion (P = 0.352) compared with patients who did not fulfill the respective MetS criteria. When all MetS traits were entered simultaneously into one ANCOVA model, only low HDL cholesterol proved associated with CRP (F = 44.19; P < 0.001) independently of age, sex, LDL cholesterol, smoking, major cardiovascular medications, and of all other MetS criteria.
CRP increased significantly (Ptrend <0.001) with an increasing number of MetS traits (A) after adjustment for age, sex, smoking, LDL cholesterol, and major cardiovascular medications. Further adjustment for the high waist (F = 11.66; P = 0.001), the high glucose (F = 14.18; P < 0.001), the high blood pressure (F = 17.94; P < 0.001), and the high triglyceride (F = 32.81; P < 0.001) traits rendered this relationship virtually unchanged. In contrast, the positive association between the number of metabolic traits and CRP was no longer significant (B) after adjustment for the low HDL cholesterol criterion (F = 0.87; P = 0.352).
Figure 1 A: Relationship of the number of MetS components and CRP adjusted for age, sex, LDL cholesterol, smoking, and major cardiovascular medications. B: Further adjustment for the low HDL criterion. P value is given for the association of CRP with the number (more ...)