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Strong evidence suggests that systemic inflammation and central adiposity contribute to and perpetuate metabolic syndrome. All of these alterations predispose individuals to type 2 diabetes mellitus (T2DM), cardiovascular disease, as well as Alzheimer's disease (AD), all characterized by chronic inflammatory status. On the other hand, extensive abnormalities in insulin and insulin-like growth factor I (IGF-I) and IGF-II signaling mechanisms in brains with AD have been demonstrated, suggesting that AD could be a third form of diabetes. The Src homology domain-containing inositol 5-phosphatase 2 (SHIP2) has an important role in the insulin pathway because its over-expression causes impairment of insulin/IGF-1 signaling. Because some single-nucleotide polymorphisms (SNP) of the gene encoding SHIP2 were significantly associated in T2DM patients with metabolic syndrome and some related conditions, we decided to conduct a case-control study on this gene, analyzing AD and T2DM subjects as cases and young, old, and centenarians as controls. Our results suggest a putative correlation between the the rs144989913 SNP and aging, both successful and unsuccessful, rather than age-related diseases. Because this SNP is an insertion/deletion of 28 bp, it might cause an alteration in SHIP2 expression. It is noteworthy that SHIP2 has been demonstrated to be a potent negative regulator of insulin signaling and insulin sensitivity. Many studies demonstrated the association of the insulin/IGF1 pathway with aging and longevity, so it is tempting to speculate that the found association with SHIP2 and aging might depend on its effect on the insulin/IGF-1 pathway.

Aging has a striking impact on the heart and the vascular system, particularly on the large elastic arteries (i.e., aorta), resulting in a multitude of changes at different structural and functional levels. As result, medial degeneration (MD) occurs. A characteristic example of MD is sporadic thoracic aortic aneurysm (S-TAA), whose patho-physiological mechanisms remain unclear. In this study, typical MD morphological phenotypes were researched in S-TAA cases and control aorta specimens by histopathological and immunohistochemical analyses. Three phenotypes (I, II, and III) were detected, but mainly the phenotype III was observed. Elevated cystic MD, plurifocal medial apoptosis, and increased metalloproteinase-9 amount characterize it. In addition, it was significantly correlated with the severity of elastic fragmentation, hypertension, and smoking, and particularly with advancing age. Thus, phenotype III might represent the typical MD phenotype associated with S-TAA in old people that have a major risk of aorta rupture and dissection independently on aneurysm diameter. This might permit the assumption that phenotype III with its typical histological abnormalities is an optimal biomarker of rupture and/or dissection in aged individuals and is useful both for applying different surgical approaches and providing appropriate surgical indications