Association of body composition, blood pressure, physical activity and fitness with cardiovascular and metabolic health in children

Background: Cardiovascular disease (CVD) has its origin early in life and is the number one cause of death worldwide. Obesity is a main predictor of the pathophysiological development of hypertension and cardiometabolic disease. Insufficient physical activity and fitness lead to overweight and obesity from childhood until adulthood. Advanced glycation end products (AGEs) accumulate in adults with micro- and macrovascular complications. Therefore, the association of cardiovascular risk factors such as childhood obesity, high blood pressure and physical inactivity with cardiometabolic health need to be investigated in a systems physiology approach.
Aims:We aimed to investigate the association of obesity, high blood pressure, physical activity and fitness with micro- and macrovascular health in young children. Furthermore, we aimed to examine whether AGEs are related to cardiovascular risk factors early in life.
Methods: First, we conducted a systematical review and meta-analysis in over 5000 children to investigate the association of body mass index (BMI), blood pressure and physical fitness with retinal vessel diameters. An electronic literature search was performed throughout the databases of PubMed, EMBASE, Ovid, Web of Science and the Cochrane Register of Controlled Trials.
In a cross-sectional approach, over 1000 children (aged 7.2±0.4 years) were screened for BMI, blood pressure, retinal arteriolar (CRAE) and venular diameters (CRVE), pulse wave velocity (PWV) and subcutaneous AGEs. A shuttle run and a 20-m sprint test were performed to assess physical fitness parameters in children. Physical activity was reported by questionnaires. Based on data from the population-based German KiGGS Study and according to the American Academy of Pediatrics guidelines, blood pressure was categorised in children with normal, high-normal blood pressure and hypertension.
Results: Our results showed that CRAE and PWV were associated with obesity and high blood pressure. Low physical fitness and physical inactivity (screen time) in childhood were determinants for unfavourable micro- and macrovascular health, but not independent of BMI and blood pressure. Moreover, physical fitness and screen time were independently associated with a higher accumulation of subcutaneous AGEs.
Conclusions: Our study showed that obesity and high blood pressure are associated with vascular alterations already in young children. We found a beneficial association of physical fitness with vascular health and AGEs. Future primary prevention programs will have to address the improvement of physical activity and fitness to promote cardiometabolic health in children. Cardiovascular risk stratification using different vascular screening tools may be important to help recognize subclinical changes in children at risk. Long-term follow-up studies are needed to clarify whether early cardiovascular changes are predictive for the development of cardiometabolic disease later in life.