Sex differences in peripheral artery intima, media and intima media thickness in children and adolescents.

Objective: Males have higher coronary heart disease (CHD) lifetime risk and increased magnitude of atherosclerosis, compared with women. Using very high-resolution ultrasound, we have shown that the intima thickness (IT) of radial and dorsal pedal arteries, measured separately from the media thickness (MT), increases with age. We wanted to test whether there is already a difference between the sexes in childhood for IT, MT and intima media thickness (IMT) in the radial and dorsal pedal arteries.

Methods And Results: A total of 252 children (age 14.5 years S.D.+/-1.0girls/boys 139/113) from two schools in Gothenburg, Sweden, participated in the study. The high-resolution (55MHz) ultrasound measurements showed that boys had larger values than girls for the radial IT (0.057+/-0.010mm vs. 0.054+/-0.008mm, P=0.007), MT (0.176+/-0.033 vs. 0.153+/-0.025, P=0.031), IMT (0.232+/-0.035 vs. 0.207+/-0.026, P=0.000), and for dorsal pedal artery MT (0.160+/-0.039 vs. 0.149+/-0.034, P=0.022) and IMT (0.222+/-0.041 vs. 0.209+/-0.037, P=0.016).

Conclusion: With this new very high-resolution ultrasound technique, we demonstrated in a large study population of children, that both intimal and medial arterial wall layers were thicker in boys than in girls. These findings may constitute an "early background" explaining why CHD starts sooner in men compared with women.