Normative and mean carotid intima-media thickness values according to metabolic syndrome in Koreans: the Namwon study

Objectives: We determined the gender- and age-specific normative values of carotid intima-media thickness (IMT) in a healthy Korean population. We also present the mean age-specific carotid IMT values according to the presence of metabolic syndrome (MetS) and the number of MetS components.

Methods: A total of 9374 subjects from the Namwon Study aged 45-74 years were included in the analysis. Subjects without hypertension, diabetes, dyslipidemia, obesity, and current smoking were classified as the healthy reference population (n = 2595). MetS was identified by the presence of three or more of the following five components: abdominal obesity, high triglycerides, low high-density lipoprotein cholesterol, high blood pressure, and high fasting blood glucose. Common carotid artery IMT (CCA-IMT) and carotid bulb IMT values were determined in a region free of plaque by B-mode carotid ultrasonography.

Results: The mean normative CCA-IMT values of 45-49, 50-54, 55-59, 60-64, 65-69, and 70-74 year old males were 0.614, 0.671, 0.711, 0.759, 0.783, and 0.787 mm and 0.613, 0.653, 0.689, 0.718, 0.753, and 0.778 mm for females, respectively. An increase in CCA-IMT of 0.007 mm/year was estimated in both genders. The mean CCA-IMT values of subjects with 0, 1, 2, 3, 4, and 5 MetS components were 0.744, 0.753, 0.765, 0.766, 0.771, and 0.798 mm for males and 0.688, 0.705, 0.724, 0.734, 0.757, and 0.762 mm for females, respectively.

Conclusion: The gender-specific normative carotid IMT values were determined in a large healthy Korean population. An increasing trend in the CCA-IMT values was observed with an increasing number of MetS components in both genders.