Abstract
It has been known that atherosclerosis suddenly develops after menopause in women, suggesting the presence of the interrelationship between atherosclerosis and estrogen deficiency. The purpose of this study is to investigate the interrelationship between arterial calcification and serum estradiol levels and bone mineral content in the aged. Seventy-seven postmenopausal women (age 47-82, mean 71 years old) and 59 mean(age 41-91, mean 70 years old) were subjected to thi study. Presence or absence of the arterial calcification was examined macroscopically by X-ray films, serum estradiol was measured by radioimmunoassay, and radial mineral con tent was measured by Bone Mineral Analyzer.
The results were as follows; (1) Arterial calcification and serum estradiol; In women, the mean serum estradiol level (11.5±1.3pg/ml) in those with calcification of the abdominal aorta was significantly lower than that (15.7±2.5pg/ml) in those without it (p< 0.01), and serum estradiol level (8.4±1.4pg/ml) in those with calcification of the iliac artery was sifnificantly lower than that (16.1±1.6pg/ml) in those without it (p<0.001). In men, the mean serum estradiol level (19.2±2.5pg/ml) in those with calcification of the iliac artery was significantly lower than that (29.7±2.4pg/ml) in those without it (p<0.01). (2) Arterial calcification and radial mineral content (RMC); In women, RMC (0.46±0.02g/cm2) in those with calcification of the abdominal aorta was significantly lower than that (0.52±0.02g/cm2) in those without it (p<0.02), and RMC (0.44±0.02g/cm2) in those with calcification of the iliac artery was significantly lower than that (0.52±0.01g/cm2) in those without it (p< 0.001). In men, there was no relationship between arterial calcification and RMC.
(3) Serum estradiol and RMC; In women, there was a positive correlation between serum estradiol level sand RMC (Y=0.0025X+0.4551, X=serum estradiol level Y=RMC, p<0.02). In men, there was no correlation between serum estradiol and RMC.
These results suggest that in both women and men, decrease of endogenous estrogen might accelerate the arterial calcification, and that the estrogen might protect the artery from calcification through a direct action on the arterial wall. Only in case of women, increased bone resorption might partly contribute to the arterial calcification.