Alterations of the cardiovascular system and the circadian rhythm are frequent complications seen in obese children and adults. In this context we aim to decipher the communication of adipose tissue and the cardiovascular system as well as the circadian rhythm in obese children and young adults.
Development of obesity in children
In order to prevent obesity and to study factors that contribute to development of obesity in children, one first need to know when obesity manifests in children and whether there is a critical age. For this we study longitudinal data of the CrescNet registry (Kess 2017) and track the development of obesity throughout childhood years. Furthermore, we are analyzing growth curves and circulating factors of normal-weight and obese children in order to characterize differences in linear growth, pubertal development and endocrine profile.
With our LIFE Child cohort then, we are studying contributing factors for development of obesity beyond the clinical features, including psychosocial, familial and environmental factors (Poulain 2018).
Development of metabolic and cardiovascular comorbidities of childhood obesity
Although "classical comorbidities" such as cardiovascular disease (hypertension, vascular dysfunction) and diabetes are usually diagnosed in adults, the pathogenesis and even the onset of these complications is much earlier, already during childhood.
In parallel with the increasing fat mass, children with obesity show first alterations in metabolic and cardiovascular system. Obese children have an increased prevalence of high blood pressure, impaired vascular function and first alterations in myocardial function (Mangner 2014). In order to identify new predictors and mechanisms of obesity-related cardiovascular dysfunction we want to decipher the interaction of adipose tissue and the cardiovascular system in children. Adipokines, molecules produced and secreted by the adipose tissue, may directly contribute to the development of cardiovascular dysfunction as has been shown for chemerin (Landgraf 2012), CTRP5 (Schwartze 2017) and osteopontin (Schreier 2016).
To assess metabolism in obese children (Körner 2013, Körner 2007) and identify pre-diabetic conditions in children and the children prone for it remains a challenge. In part this is due to the fact that there are no child-specific criteria and reference ranges for glucose parameters and no references ranges for insulin during an oral glucose tolerance test. We, therefore, establish those insulin reference ranges in a cohort of lean healthy children and on the basis of that evaluate the prevalence of insulin resistance in obese children. Further on, we aim to identify risk factor for the early development of insulin resistance in children.
Dysregulation of the circadian rhythm system has already been linked to the development of obesity and obesity-related complications. We ask whether diurnal adipocytokine serum level fluctuations differ between lean and obese people. We also want to assess if those differences correlate with anthropometric and metabolic characteristics and in what way food intake, oral glucose tolerance testing, and physical exercise influence clock gene expression. In order to study these effects we created the Leipzig Circadian Rhythm Cohort.
On the basis of our findings we hope to identify new efficient strategies to improve cardiovascular function in obese children. For this we created the Leipzig Atherobesity Childhood Cohort (KFO/SFB) in which we are prospectively studying metabolic and cardiovascular alterations in lean and obese children.
