Microvascular function is impaired in children with morbid obesity

Children's obesity is a growing problem in Western societies. We hypothesized that morbid obesity (body mass index [BMI] > 99.5th percentile) might affect microvascular function at an early stage. Therefore, we assessed the microvascular function of 41 obese children (13.2 +/- 2.8 years, BMI 32.9 +/- 6.6) in comparison to 91 healthy controls (12.7 +/- 2.1 years, BMI 18.2 +/- 2.5) by post-occlusive reactive hyperemia measured by a laser Doppler: baseline perfusion, biological zero (defined as 'no-flow' laser Doppler signal during suprasystolic occlusion), peak perfusion (following occlusion), time to peak perfusion and recovery time (time until resuming baseline perfusion) were recorded and compared between both groups. Peak perfusion was higher in children with morbid obesity than in controls (1.67 +/- 0.76 AU [arbitrary units] vs 1.26 +/- 0.5 AU, p < 0.001). Consecutively, recovery time was longer in children with morbid obesity (118.21 +/- 34.64 seconds) than in healthy children (83.18 +/- 35.08 seconds, p < 0.001). In conclusion, higher peak perfusion and prolonged recovery time in children with morbid obesity seem to reflect microvascular dysfunction due to an impaired vasoconstrictive ability of precapillary sphincters.