Age-related differences in calcium accumulation in human arteries.

To elucidate the accumulation of calcium in the human arteries, the calcium contents of the thoracic aorta, coronary, common carotid, basilar, internal thoracic, axillary, radial, femoral, popliteal, and dorsalis pedis arteries, were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The calcium content began to increase in both the thoracic aorta and femoral artery around the age of 50 years (yrs), in the popliteal artery at the age of 60 yrs, in the coronary, basilar and dorsalis pedis arteries at the age of 70 yrs, and in the common carotid artery at the age of 80 yrs. In the same time, the calcium content did not increase significantly in the internal thoracic and radial arteries. Accumulation of calcium in human arteries was classified into two groups: The first is an age-related increase of calcium content in the arteries like the thoracic aorta, coronary, common carotid, basilar, axillary, femoral, popliteal and dorsalis pedis arteries. The second is non-age-related, such as the internal thoracic and radial arteries. To examine the localization of this calcium accumulation, the thoracic-aortic and femoral-arterial walls were separated into the three tunicae, intima, media and adventitia. In the case of the thoracic aorta, the accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, secondarily in the tunica intima. With regard to the femoral artery, the accumulation of calcium and phosphorus occurred only in the tunica media, only in the tunica intima, or in both the tunicae media and intima. Therefore, the manner of accumulation of calcium and phosphorus in the femoral-arterial wall was different from that in the aortic wall. Comparing the upper and lower limb arteries, the calcium content was found to be higher in the femoral, popliteal, and dorsalis pedis arteries of the lower limb than that of the axillary and radial arteries of the upper limb.