The associations between the changes in serum inflammatory markers and bone mineral accrual in boys with overweight and obesity during pubertal maturation: a 3-year longitudinal study in Estonian boys.

Adipose tissue produces different inflammatory cytokines which compromise bone mineral accrual during puberty. Vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), interleukin (IL)-8, and interferon-gamma (IFN-γ) are significantly related to bone mineral accrual during pubertal maturation in boys with different BMI values. INTRODUCTION: This longitudinal study aims to identify the inflammatory markers that most strongly associate with pubertal bone mineral density (BMD) increment in boys with overweight and obesity (OWB). METHODS: Twenty-six OWB and 29 normal-weight boys were followed yearly for 3 years to measure changes in 12 serum inflammatory markers, BMD (by DXA), and apparent volumetric BMD. The OWB group was further divided into two subgroups according to their BMI gain during the 3-year period. Data through time points presented as slopes were used to calculate correlation coefficients to explore the possible relationships between variables of interest. In the whole study group, linear mixed effects (LME) models were also used. RESULTS: Increment in serum VEGF concentration was inversely associated with an increase in total body (TB) BMD (r = - 0.82, P = 0.02) and TB bone mineral content (BMC)/height (r = - 0.82, P = 0.02) in those OWB whose BMI gain was higher during pubertal years. In the whole study group, the LME model confirmed the inverse association between VEGF and TB BMC/height (P < 0.05). EGF was inversely associated with LS BMD and LS BMAD (P < 0.05), whereas there was a positive association between IL-8 and TB BMAD and between IFN-γ and LS BMD (P < 0.05). CONCLUSIONS: Lower increment in BMD in OWB with higher BMI gain is associated with increasing serum VEGF concentration during pubertal maturation. VEGF, EGF, IL-8, and IFN-γ are significantly associated with BMD during pubertal maturation in boys with different BMI values.

Vigorous physical activity patterns affect bone growth during early puberty in boys.

This study aims to analyze the impact of participation in vigorous physical activity as it can promote a healthy bone development. Adolescents who increased their participation in vigorous physical activity showed higher improvements in bone parameters compared to those who did not, which highlights the relevance of vigorous physical activity engagement. INTRODUCTION: The main purpose of the study was to analyze the effects of different patterns of vigorous physical activity (VPA) on bone development. METHODS: One-week accelerometry registers and dual-energy X-ray absorptiometry scans at the whole body, hip, and lumbar spine of 140 healthy male adolescents (11-13 years, at baseline) were performed twice with a 1-year interval between measurements. Four patterns of VPA evolution ("low-low," "low-high," "high-low," and "high-high") and three patterns of bone growth ("optimal," "mean," and "reduced") were defined according to the median participation in VPA and a cluster analysis of the longitudinal changes in BMC and BMD in all sites measured, respectively. Bone mineral parameters were adjusted for skeletal age and body weight prior to statistical comparison among groups. RESULTS: Participants in the "low-high" group had greater adjusted BMD increases at both the femoral neck and lumbar spine when compared to the "low-low" group (estimated mean (95% CI) 0.066 (0.047-0.085) vs. 0.034 (0.021-0.047) g/cm2 and 0.074 (0.054-0.093) vs. 0.049 (0.035-0.062) g/cm2 respectively, both p < 0.05). Femoral neck BMD adjusted increase was also different between the "high-high" and the "high-low" groups (0.053 (0.041-0.066) vs. 0.030 (0.011-0.049) g/cm2, p < 0.05). Additionally, a higher percentage of "optimal" growth was found in the "low-high" group than in the "low-low" and "high-low" categories (36.3, 12.5 and 13.6% respectively, p < 0.05). CONCLUSIONS: Engaging in VPA as well as maintaining high levels of VPA during puberty is associated with greater gains in bone mass, which can have an impact in future bone health.