High accumulation of calcium and phosphorus in the coronary artery of the Thai in comparison with the Japanese

To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the coronary arteries of Thai and Japanese. The Thai subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr, whereas the Japanese subjects consisted of 17 men and 9 women, ranging in age from 55 to 92 yr. After the ordinary dissections at Chiang Mai University and Nara Medical University were finished, the coronary arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the Thai, an accumulation of calcium and phosphorus began to occur in the forties and increased markedly in the fifties, whereas in the Japanese, an accumulation of calcium and phosphorus began to occur in the seventies and increased markedly in the nineties. The result revealed that an accumulation of calcium and phosphorus occurred earlier in the Thai than in the Japanese. Regarding the relationships among element contents, extremely significant correlations were found between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in both the coronary arteries of the Thai and the Japanese. As far as the coronary arteries with a very high accumulation of calcium and phosphorus, the mass ratios of magnesium to calcium and phosphorus were lower in the coronary arteries of the Thai in comparison with the Japanese.