Cytokines and clustered cardiovascular risk factors in children

Area of Science:

• Pediatric cardiovascular health
• Inflammation and metabolic disease
• Childhood obesity and fitness

Background:

• Cardiovascular disease (CVD) risk factors and insulin resistance often cluster in childhood.
• The role of specific inflammatory markers like tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) in early CVD risk factor clustering is not fully understood.

Purpose of the Study:

• To investigate the association between inflammatory markers (TNF-alpha, IL-6, C-reactive protein [CRP]), fitness, fatness, and the clustering of CVD risk factors and insulin resistance in 9-year-old children.
• To determine if low fitness and high fatness are linked to these inflammatory markers and CVD risk profiles.

Main Methods:

• Cross-sectional study of 210 third-grade children (aged 9) selected from a larger cohort in Denmark based on their cardiovascular disease (CVD) risk profiles.
• Analysis included cytokine levels (TNF-alpha, IL-6), CRP, fitness (VO2peak), fatness, and composite CVD risk scores.
• Subgroup analysis compared children in the upper and lower quartiles of the CVD risk score.

Main Results:

• CVD risk factors and CRP levels differed significantly between high-risk and low-risk groups.
• Strong associations were observed between CVD risk scores and fitness or fatness.
• No significant associations were found between CVD risk scores and TNF-alpha or IL-6 levels.
• CRP was associated with fitness, fatness, and the CVD risk score, indicating higher inflammation in unfit and overweight children.

Conclusions:

• This study does not support a direct association between plasma IL-6 or TNF-alpha and low insulin sensitivity or clustered CVD risk factors in this young cohort.
• Inflammation, as indicated by CRP, is more pronounced in children with lower fitness and higher fatness.
• Other mechanisms likely mediate the relationship between fitness, fatness, insulin resistance, and clustered CVD risk.