Aim: Carotid intima-media thickness (IMT) is a useful surrogate marker of cardiovascular disease and is associated with cardiac events. We investigated cross-sectionally the association between carotid intima-media thickness (IMT), confounding risk factors, and metabolic syndrome (MetS) using the modified Japanese criteria.
Methods: Carotid IMT was evaluated on B-mode ultrasonography in 918 patients (394 men aged 66 +/- 15 years and 524 women aged 72 +/- 13 years).
Results: Among our 918 patients, 74 (8.1%) had no metabolic abnormalities, 478 (52.1%) had a metabolic abnormality with neither type 2 diabetes or MetS, and 127 had MetS without diabetes. Of the patients with type 2 diabetes, 132 (14.4%) did not have MetS and 107 (11.7%) had both type 2 diabetes and MetS. The carotid IMT values in the four groups with any metabolic abnormalities were significantly greater than the IMT of the group with neither condition (p=0.001), respectively. In syndrome model, type 2 diabetes was significantly associated with carotid atherosclerosis (p= 0.006), but MetS was borderline significant. In the component model of MetS, there was a significant association with hypertension (p<0.001) and dyslipidemia (p=0.006). Multiple logistic regression analysis for carotid atherosclerosis compared to neither condition demonstrated that subjects with both MetS and diabetes (OR, 5.58; 95% CI, 2.64-11.8), those with type 2 diabetes without MetS (OR, 3.00; 95% CI, 1.45-6.22), and those with MetS without type 2 diabetes (OR, 2.58; 75% CI, 1.24-5.39) showed a higher odds ratio after adjustment for covariates.
Conclusion: Even after taking into account each individual component of MetS, the clustering of visceral obesity with at least 2 of the 3 components, and diabetes are independently associated with increased carotid IMT. This suggests that the components of MetS and type 2 diabetes interact to affect vascular thickness synergistically.