Atherosclerosis, Mummies and Histological Analysis: A Review

Atherosclerosis has always been considered as a pathology of modern life, but we know by now that it is an inevitable condition of human ageing. In fact arterial degeneration begins early in postnatal life and is progressive in all human populations even if the degree of atherosclerosis can be delayed by a lifelong avoidance of lifestyle risk factors [Wang et al., 2010]. Among the modifiable risk factors, it is clear that in general the average population of the past had poor access to fatty and well-seasoned food and practiced intense physical activity in comparison to the modern population. In every period there have been élite social classes in which there is a high consumption of fatty food associated with lack of physical exercise. Atherosclerotic disease has been identified, however, in individuals from very different social contexts and with different standard of living. For this reason we believe that a fundamental role has been played by the infectious diseases and chronic inflammatory conditions. For the past populations infections would have been very common in the daily life and it was the major cause of death. Several studies demonstrated that a prolonged inflammatory response might accelerate an atherosclerotic process in those patients who suffer from chronic inflammatory disease like rheumatoid arthritis or systemic lupus erythematosus [Kahlenberg & Kaplan, 2013]. Since atherosclerosis begins as an inflammatory reaction against endothelial cells and other components of the artery wall, it is important to take into account the role of proper oral hygiene in order to avoid periodontitis, which is a chronic inflammatory disease that affects the periodontium. Bacterial populations on the tooth surfaces are extremely numerous and it is crucial that commensal bacteria would not overwhelmed by pathogenic strains; for example, Gram-negative bacteria, has been reported to be a significant predictor of coronary heart disease [Meurman et al., 2004]. Some supposed mechanisms by which dental bacteria may contribute to the atherosclerotic disease are the activation of innate immunity and the direct involvement of mediators activated by dental plaque [Bartova et al., 2014] For many years the anthropological studies have focused on the oral state of health, highlighting that the populations of the past suffered from different pathologies caused by incorrect eating practices or by lack of oral hygiene or by the use of the teeth as ‘third hand’. Caries, for example, is a very old disease. It has been reported in several lineages of fossil hominines like Homo habilis, H. erectus, H. heidelbergensis and H. neanderthalensis [Lanfranco & Eggers, 2012] and follows the increase of carbohydrates intake in human history from the advent of agriculture to the recently dietary changes of the Industrial Revolution. In conclusion, inflammation associated with lack of oral hygiene could have played a part in atherosclerotic disease process. Given the post-mortemchanges seen in the vessel walls of a mummy, obtaining histologic specimens is important to confirming the diagnosis of an atherosclerotic plaque. While CT scans can be used to identify atherosclerosis in ancientmummies, this approach only detectsplaques that have already been calcified, and histological examination is necessary to detect early stages of disease. CT scans can be used to identify atherosclerosis in ancient mummies, this approach only detects plaques that have already been calcified, and histological examination is necessary to detect early stages of disease. The development of vascular calcification is related not only to atherosclerosis Other conditions may lead to the formation of such lesions, including aging, diabetes, disorders of calcium-phosphorus metabolism, chronic microinflammation, hyperhomocysteinemia, and chronic renal insufficiency (Davies MR, Hruska KA. Pathophysiological mechanisms of vascular calcification in end-stage renal disease. Kidney Int. 2001;60(2):472-479.) Moreover, given the poor state of preservation of the organic tissues, a differential diagnosis for the findings should include parasitic calcifications in lymphatic vessels (particularly from filariasis). While there are other diseases such as syphilis, which can cause vascular calcification, the pattern and distribution of arterial calcification related to atherosclerosis is quite distinctive. When observing a vascular calcification on a CT (particularly 6-slice), it is not possible to distinguish lesions of atherosclerosis and mediacalcosis (Charlier, 2010)