Comparative studies of atherosclerosis in swine.

A survey of spontaneously occurring fatty streaks and fibrous plaques, considered as atherosclerosis, in 1637 swine in different European countries and the USA, using a standardized procedure, was undertaken to determine whether significant differences exist in the occurrence and extent of the disease in various groups of animals. At the same time a preliminary study on the possible relation of any differences observed in atherosclerosis to certain environmental and constitutional factors was carried out with the ultimate goal of contributing to the understanding of analogous problems in man.STATISTICALLY SIGNIFICANT INCREASES OF FATTY STREAKS AND FIBROUS PLAQUES WERE NOTED IN RELATION TO: (a) increasing age, starting at 6 to 7 months, the earliest age period studied; (b) geographical locality; and (c) considerable as compared with moderate or slight physical activity at 1 year of age. Although not statistically significant, there was also a suggestive trend towards more atherosclerosis in pigs consuming soft water as compared with those consuming hard water.While these correlations may represent contributory factors to the increases of the changes noted in the abdominal aortas, it is not possible to pinpoint the importance of individual components because of the limited data and the large number of variables involved in this preliminary study. Studies in swine and other animals are being encouraged in which all variables but one are being kept constant to determine their possible role in the development of atherosclerotic lesions.