Stiffness and aneurysm of the aorta. Relations to vascular aging, hyperglycemia, and inflammation

Sammanfattning: A well-functioning arterial system for the transport of oxygen to the cells is essential for human health. The aorta has a key role for the provision of this physiological effect. Disturbances to aortic function can lead to majorsymptoms and even death due to ruptured abdominal aortic aneurysm (AAA). Multiple diseases may exacerbate, or alleviate the symptoms of aortic conditions.This thesis examines the following features potentially affecting aortic function:Aortic stiffness; the wall of the aorta loses its elasticity and blood travels with excessive speed Horizontal/radial expansion of the abdominal aorta, referred to as AAA Diabetes mellitus (DM), excessive concentration of glucose in the blood streamThe above relationships are complex and the pathways not yet fully clarified by contemporary medical research.Research has implied a positive link between type 2 DM (DM2) and stiffening but a negative link between typeDM2 and AAA, indicating a need for more studies about details in these correlations. The purpose of this thesishas been to investigate relationships between:DM2 and aortic stiffnessBiomarkers and AAADM2 and AAAThe research has used data obtained from a number of primary sources:The cardiovascular arm of the Malmö Diet Cancer Study, and the Malmö Offspring StudyNational and regional diabetes registriesThe Swedish Vascular Register, SwedvascThe ultrasound screening program for AAA in MalmöStatistical calculations have been used with the concept of significance as the pivotal measure of whether anassociation could be proven or not. This has yielded a total of five papers, all published in scientific journals withvarious co-authors. The main conclusions are:DM2 is related to aortic stiffness, primarily in older individuals.None of six evaluated plasma biomarkers predicted aortic diameter 15 – 20 years laterThe reported protective effect of DM2 on AAA could not be detected in the early stages of DM2During follow-up after elective endovascular AAA repair, DM2 was associated with lower need of re-interventionDuring follow-up after acute AAA repair, DM2 was associated with lower rates of cardiovascular diseases andmortalityPlausible explanatory theories for the above mechanisms are discussed, and further research is needed to identify which of these that are most clinically relevant.