Background: Effective prevention of atherosclerosis requires identification of individuals at high risk already in childhood. Adipose tissue produces various proteins that participate in the regulation of metabolism and have been suggested to influence the cardiovascular system directly and via inflammation. 

Aims: The aims of this study were to examine serum levels of adipose tissue-derived proteins adiponectin and leptin in Finnish children, adolescents and adults and to study their associations with metabolic syndrome, carotid intima-media thickness and flow-mediated dilatation of the brachial artery. Moreover, the aim was to study if adiponectin levels in childhood and adolescence predict carotid atherosclerosis in adulthood. 

Participants and methods: The present thesis is part of the Cardiovascular Risk in Young Finns Study. In 1980, 3,596 children and adolescents aged 3-18 years participated in the study. Serum adiponectin concentrations were measured from samples taken in 1980, 2001 and 2007 and leptin concentrations from samples taken in 1980 and 2001. Ultrasonic evaluation of carotid artery intima-media thickness and brachial artery flow-mediated dilatation were performed in 2001 and 2007. 

Results: Serum adiponectin levels decreased from childhood to adulthood in both males and females whereas serum leptin levels increased in females and decreased slightly in males. In adulthood, decreased serum adiponectin levels were associated with incident metabolic syndrome, increased carotid artery intima-media thickness and attenuated flow-mediated dilatation of the brachial artery. Serum adiponectin levels in childhood were inversely associated with carotid atherosclerosis in adulthood. There were no independent associations between leptin levels and surrogate markers of atherosclerosis. 

Conclusions: Serum adiponectin, but not leptin, levels may be a useful biomarker in cardiovascular risk assessment.