Calcification of the internal elastic membrane in temporal arteries: its relation to age and gender.

OBJECTIVE To investigate the age and sex distribution of calcifications of the internal elastic membrane (IEM) in temporal arteries. METHODS Calcifications of the IEM were assessed light-microscopically in temporal arteries from 40 women and 21 men, aged 51 or more, who were known not to have giant cell arteritis (GCA). Their relation to age and the difference between women and men were tested statistically. RESULTS The IEM calcifications differed morphologically from the calcifications in Mönckeberg's mediosclerosis and atherosclerosis. They increased significantly with age and were 2.62 times more common in women than men. CONCLUSION Previous morphological studies indicate that the inflammatory process in GCA is initiated by a foreign-body, giant-cell attack on calcifications of the IEM. The present study showed that IEM calcifications in non-GCA controls show an age and sex distribution similar to that of GCA morbidity. The results may indicate that the presence of IEM calcifications in the general population influences the age and sex distribution of GCA. Furthermore, the findings support the hypothesis that the calcifications, although not disease specific, may play a pathogenetic role in the latter.