Body fat distribution, inflammation and cardiovascular disease

Abstract: Cardiovascular disease (CVD) is one of the major health issues of our time. The prevalence of CVD is increasing, both in industrialized and in developing countries, and causes suffering and a decreased quality of life for millions of people worldwide. CVD can have multiple etiologies, but the main underlying cause is atherosclerosis, which causes blood clot formation and obstructs vital arteries.Multiple risk factors of atherosclerosis have been identified, and body fatness is one of the most important ones. The main aims of this thesis were to investigate the relation between body fatness and: CVD risk factors (paper I), incident stroke (paper II), and overall mortality (paper III). The results showed that abdominal obesity is strongly associated with both CVD risk factors and stroke incidence (papers I-II). The results also suggested that a substantial part of the association between increased body fat and stroke can be explained by an increase in traditional stroke risk factors associated with increased body fat (paper II). A gynoid fat distribution, with a high share of fat located around the hip, is, on the other hand, associated with lower risk factor levels in both men and women, and with a decreased risk of stroke in women (papers I-II). This illustrates the importance of assessing the overall distribution of body fat rather, than solely focusing on total body fatness.In elderly women, total body fat was found to be associated with increased survival, while abdominal fat moderately increased mortality risk (paper III). Lean mass (fat-free mass) was strongly associated with increased survival among elderly men and women (paper III).Erythrocyte sedimentation rate (ESR) is an indicator of inflammation and, possibly, an indicator of atherosclerotic disease. In paper IV, the relationship between ESR in young adulthood and the later risk of myocardial infarction (MI) was studied. Results showed that higher levels of ESR were associated with a higher MI risk, in a dose-responsive manner, and was independent of other well-established risk factors.In summary, both total and regional fat distribution are associated with CVD risk factors and stroke, but do not seem to correspond to an increase in mortality risk among the elderly. Also, inflammation, detected as an increase in ESR, is associated with long term MI risk in young men.