Age- and Gender-associated Determinants of Carotid Intima-media Thickness: a Community-based Study

Aim: Few population-based studies have assessed the risk factors of and gender differences in intima-media thickness (IMT) at the common carotid artery (CCA) for different age groups.

Objective: Factors determining age and gender differences in IMT were studied in ethnic Chinese participants of the Chin-Shan Community Cardiovascular Cohort in Taiwan.

Methods: From July 1994 through August 1996, the CCA-IMT of 1203 men and 1487 women aged 35 years or more was measured using high-resolution B-mode carotid ultrasound. Cardiovascular risk factors were recorded for each subject.

Results: The CCA-IMT consistently increased with age and was more in men than in women. For participants aged 55 years or more, women showed a more rapid increase in systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDL) than men. The gender difference in CCA-IMT became insignificant after 75 years of age. The major determinants of CCA-IMT in addition to age and gender were body mass index at 35-44 years of age, LDL in both genders and SBP in women at 45-54 years old, SBP at 55-64 and 65-74 years old, and women with left ventricular hypertrophy, hypertension with medication, and high LDL levels at 65-74 years old after multivariate linear regression analysis. For those aged over 75 years, SBP was an important determinant of CCA-IMT.

Conclusions: The CCA-IMT increases with age and its determinants are associated with age and gender. The rapid increase in cardiovascular risk factors in women after 55 years of age attenuates the female advantage in CCA-IMT.