Elsevier

Clinical Radiology

Volume 64, Issue 11, November 2009, Pages 1097-1103
Clinical Radiology

Factors associated with gender difference in the intima–media thickness of the common carotid artery

https://doi.org/10.1016/j.crad.2009.06.009Get rights and content

Aim

To investigate the gender differences associated with a thinner intima–media thickness (IMT) of the common carotid artery (CCA) in women.

Materials and methods

In a sample of 218 consecutive healthy volunteers comprising 110 men and 108 women, the IMT of the CCA was measured using B-mode ultrasonography. Blood pressure, fasting blood sugar, body mass index (BMI), blood lipid profile, homocysteine, folic acid, uric acid, high sensitive C-reactive protein, and thiobarbituric acid reactive substances (TBARS) levels were measured and compared with each other in both genders.

Results

The IMT of the CCA was significantly thinner in women than in men (p = 0.012). Blood pressure, fasting plasma glucose, BMI, low-density lipoprotein cholesterol, triglycerides, homocysteine, uric acid, and TBARS were significantly (p < 0.05) lower, folic acid and high-density lipoprotein cholesterol (HDL-C) were significantly (p < 0.0001) higher in women compared with men. Multivariable logistic regression analysis revealed that higher serum levels of homocysteine, uric acid, and TBARS, and lower serum levels of HDL-C were significantly (p < 0.05) associated with male sex. Multiple linear regression analysis further revealed that age, sex, and BMI were independently associated with CCA IMT.

Conclusions

The IMT of the CCA was thinner in women than in men. Traditional vascular risk factors explain only a small amount of variance in multivariate regression models supporting the hypothesis that other behavioural, sex hormone-related or genetic factors, which have not been sufficiently explored so far, may play a role in the gender differences of IMT.

Introduction

Gender differences exist in many diseases and medical conditions. In premenopausal women, the incidence and severity of hypertension, stroke, and other vascular diseases are lower than in men at similar ages or than in post-menopausal women.1 Gender differences further exist in intermediate vascular risk factors, such as the intima–media thickness (IMT) of the common carotid artery (CCA), which is frequently used as a surrogate marker for subclinical atherosclerosis in multiple epidemiological and interventional studies.2, 3, 4

The pathophysiological mechanisms for these gender differences are still poorly understood, although emerging evidence suggests that sex hormone-dependent differences in vascular oxidative stress may play an important role.5, 6, 7 As gender is an unmodifiable risk factor for vascular diseases and the benefit of hormone-replacement therapy in women remain uncertain,8, 9 investigating for other factors than sex hormone-related differences may contribute to a greater understanding of the process of atherosclerosis.

The aim of the present study was to explore the factors associated with a thinner IMT in women.

Section snippets

Study design

This was a single-centre, observational study. The study hospital was a medical centre and a main referral hospital serving an area with 3 million inhabitants. The institutional ethics committee approved the study protocol, and informed written consent was obtained from each of the participants.

Subjects

From July 2006 to May 2007, a total of 218 consecutive volunteers (110 men and 108 women; age 18–65 years; mean age for men: 36.4 years; women: 37.7 years) who underwent an annual physical check-up were

CCA IMT is thinner in women

Table 1 presents the baseline characteristics of the 218 participants. Univariate analysis revealed that the mean IMT of the left CCA and the mean CCA IMT of both sides were significantly thinner in women than in men. In both women and men the left CCA IMT was thicker than the right CCA IMT (mean ± standard deviation; 0.556 ± 0.10 mm versus 0.529 ± 0.09 mm, p = 0.004).

Differences in demographic data and vascular risk factors between both genders

Univariate analysis (Table 1) revealed that blood pressure, fasting blood sugar, BMI, LDL-C, triglycerides (TG), homocysteine, uric acid,

Discussion

In accordance with the findings from multiple, large-scale, epidemiological studies,2, 3, 4 the present study revealed a thinner CCA IMT in women than in men in a Taiwanese population. Although the majority of those well-established vascular risk factors, which were analysed in the present study, differ significantly between men and women, only serum levels of HDL-C, homocysteine, uric acid, and TBARS as an indicator of lipid peroxidation were significantly associated with female gender in a

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