Liina Remmel will defend the dissertation "Relationships between inflammatory markers, body composition, bone health and cardiorespiratory fitness in 10- to 11-year old overweight and normal weight boys" on 30 May 2014 at 3 p.m. in the Senate Hall, applying for the degree of Doctor of Philosophy in Exercise and Sport Sciences.
Professor Jaak Jürimäe, PhD, University of Tartu
Professor Vallo Tillmann, MD, University of Tartu
Professor emeritus Toivo Jürimäe, University of Tartu
Professor Sigitas Kamandulis, PhD, Lithuanian Academy of Physical Education
Obesity has an adverse impact on health and it is a serious problem among children. Active lifestyle in childhood provides basement for better health in adulthood. Overweight children have more frequent fractures indicating a link between obesity and bone mineral density. Puberty is particularly important as this is a time when peak bone mass accumulation starts. Inflammation has a role in the development of obesity which can be assessed by measuring various inflammatory markers in serum. Therefore, measurement of inflammatory parameters in serum should indicate whether and how the inflammation in obesity may affect bone health and cardiorespiratory fitness.
Aim of this study was to investigate the associations between thirteen different serum inflammatory markers and body composition, bone health and cardiorespiratory fitness in overweight and normal weight boys at the age of 10-11 years.
Our study showed that out of thirteen measured inflammatory markers in serum interleukin-6, interleukin-8, monocyte chemotactic protein-1, C-reactive protein and interferon-γ concentration in serum was higher in overweight boys compared to normal weight boys. In addition, serum interleukin-6, tumor necrosis factor-α, C-reactive protein and interferon-γ concentration was positively correlated with body fat mass in overweight boys. These results indicate that increased fat mass is associated with high inflammation activity. Despite of greater total body bone mineral density, overweight boys had lower total body volumetric bone mineral density compared with normal weight boys that according to the literature may increase the risk for fractures in adulthood. We found a positive correlation between serum interferon-γ concentration and bone mineral density. This indicates that inflammation already in process in 10 to 11-year old overweight children may affect further increment of bone mineral density. Overweight boys had also lower cardiorespiratory fitness level measured by relative peak oxygen consumption per kilogram of body weight. The latter was negatively correlated with serum interleukin-6 concentration. Measurement of serum interleukin-6 level in overweight boys may help to identify subjects who need specific aerobic exercise formats and levels to achieve maximal beneficial health effects.