Inflammation and lifestyle in cardiovascular medicine
Abstract: Despite major advances in the treatment and prevention of atherosclerosis the last several decades, cardiovascular disease still accounts for the majority of deaths in Sweden. With the population getting older, more obese and with rising numbers of diabetics, the cardiovascular disease burden may increase further in the future.The focus in cardiovascular disease has shifted with time from calcification and narrowing of arteries to the biological processes within the atherosclerotic plaque. C-reactive protein (CRP) has emerged as one of many proteins that reflect a low grade systemic inflammation and is suitable for analysis as it is more stable and easily measured than most other inflammatory markers. Several large prospective studies have shown that CRP is not only an inflammatory marker, but even a predictive marker for cardiovascular disease. C-reactive protein is associated with several other risk factors for cardiovascular disease including obesity and the metabolic syndrome.Our study of twenty healthy men during a two week endurance cross country skiing tour demonstrated a decline in already low baseline CRP levels immediately after the tour and six weeks later.In a study of 200 obese individuals with impaired glucose tolerance randomised to a counselling session at their health care centre or a one month stay at a wellness centre, we found decreased levels of CRP in subjects admitted to the wellness centre. The effect remained at one, but not after three years of follow-up.In a prospective, nested, case-referent study with 308 ischemic strokes, 61 intracerebral haemorrhages and 735 matched referents, CRP was associated with ischemic stroke in both uni- and multivariate analyses. No association was found with intracerebral haemorrhages. When classifying ischemic stroke according to TOAST criteria, CRP was associated with small vessel disease. The CRP 1444 (CC/CT vs. TT) polymorphism was associated with plasma levels of CRP, but neither with ischemic stroke nor with intracerebral haemorrhage.A study on 129 patients with atrial fibrillation was used to evaluate whether inflammation sensitive fibrinolytic variables adjusted for CRP could predict recurrence of atrial fibrillation after electrical cardioversion. In multivariate iv models, lower PAI-1 mass was associated with sinus rhythm even after adjusting for CRP and markers of the metabolic syndrome.In conclusion, lifestyle intervention can be used to reduce CRP levels, but it remains a challenge to maintain this effect. CRP is a marker of ischemic stroke, but there are no significant associations between the CRP1444 polymorphism and any stroke subtype, suggesting that the CRP relationship with ischemic stroke is not causal. The fibrinolytic variable, PAI-1, is associated with the risk of recurrence of atrial fibrillation after electrical cardioversion after adjustment for CRP. Our findings suggest a pathophysiological link between atrial fibrillation and PAI-1, but the relation to inflammation remains unclear.
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