To Örebro University

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. Well-established risk factors for CVD include increasing age, male sex, sedentary lifestyle, obesity, smoking, diabetes, hypertension, dyslipidaemia and low socio-economic status. Traditional risk factors do, however, not fully explain cardiovascular risk in general. In this thesis we focused on two conventional risk factors (smoking, blood pressure), and two unconventional risk markers (adiponectin, an adipocyte derived protein; and sialic acid (SA), a marker of systemic inflammation) for prediction of CVD events.

Aims: In Paper I we examined to what degree smoking habits modify the risk of CVD in relation to systolic blood pressure levels in middle-aged men. In Paper II we investigated the predictive role of adiponectin for risk of CVD as well as the cross-sectional associations between adiponectin and markers of glucose metabolism, also in men. In Paper III we examined if increasing pulse pressure (PP) and increasing levels of SA both increase the risk of CVD and whether their effects act in synergism. In Paper IV the association of SA with risk of incident diabetes mellitus and related complications, resulting in hospitalization, was studied.

Subjects and Methods: Two large-scale, population-based, screening studies with long follow-up periods have been used. The Malmö Preventive Project (MPP) was used with 22,444 individuals in Paper I and a sub cohort of 3,885 individuals in Paper II. The Värmland Health Survey (VHS) was used in Papers III and IV with 37,843 and 87,035 individuals, respectively.

Results: CVD risk increases with increasing systolic blood pressure levels and this risk is almost doubled in smokers. Total adiponectin level is not associated with increased risk of future CVD but it is inversely associated with markers of glucose metabolism. PP and SA both contribute to risk of future CVD. Adjustment for mean arterial pressure reduces the risk induced by PP. Elevated SA contributes to increased risk of incident diabetes and related complications leading to hospitalization.