Obese children without comorbidities have impaired microvascular endothelial function

AIM: The aim was to test acetylcholine-induced endothelium-dependent vasodilatation in obese children without comorbidities, compared with normal weight controls, and to analyse associations between vasodilatation and other potential risk factors. METHODS: Endothelium-dependent vasodilatation was induced by transdermal iontophoresis of acetylcholine in 54 obese children (8.3-18.2 years old, 41% girls) and 44 normal weight controls (7.5-20.2 years old, 82% girls), and the subsequent change in perfusion was measured with laser Doppler flowmetry. In a subgroup of the obese children, associations between acetylcholine-induced vasodilatation and blood lipids, glucose/insulin metabolism, inflammation, 24-h ambulatory blood pressure (ABP), cardiovascular fitness and duration of obesity were evaluated. RESULTS: We found a lower endothelium-dependent vasodilatory response to acetylcholine in the obese children than the controls (p < 0.001). The peak perfusion response was 33% lower in obese children (p = 0.001). There was a trend towards lower vasodilatation in obese children with higher levels of triglycerides (p = 0.07). Children with the shortest duration of obesity exhibited the lowest vasodilatation (p = 0.03). No associations were found between 24-h ABP, cardiovascular fitness, inflammation and glucose/insulin metabolism. CONCLUSION: Obese children without comorbidities have significantly impaired microvascular endothelial function. The children who had been obese for a longer time seemed less affected.