179 Evaluation and Comparison of Lung Function by Plethysmography in Adolescents with Morbid Obesity, not Morbid Obesity and Healthy Eutrophic Children

BACKGROUND: The objective was to measure and compare lung function by plethysmography in young healthy children, obese and morbidly obese. METHODS: Cross-sectional, prospective study in 150 adolescents from 11 to 17 years old, grouped according to their body mass index (BMI): group 1 (G1) healthy eutrophic (BMI percentile 10–84 of the boards of the CDC) Group 2 (G2) not morbidly obese (BMI 85–98) and group 3 (G3), morbidly obese (BMI> 99). Anthropometry was performed and plethysmography. Statistics: mean, standard deviation (SD), confidence interval 95%, CI 95%. ANOVA post hoc analysis. RESULTS: The mean age was 13.7 years, 46.7% women and 53.3% men. G1 had 40 children, G2 had 67 and G3 had 43. Mean values and CI 95% of vital capacity (VC) of G1 was 104.97% (100.12–109.82), G2 114.65% (111.36–117.94), G3 118.09% (112.71–123.47) [G1 with significant difference compared the G2 and G3 P <0.05]. The total lung capacity (TLC) was 124.67% G1 (105.94–143.40), G2 145.61% (114.77–176.45), G3 132.27% (125.14–139.41) [no intergroup difference]. Functional residual capacity (FRC) of G1 was 145.95% (133.75–158.14), G2 122.41% (110.23–134.59), G3 115.74% (103.05–128.43) [G1 with significant difference compared with the G2 and G3 P <0.05]. The expiratory reserve volume (ERV) of G1 was 113.15% (90.57 – 135.72), G2 68.64% (60.34 – 76.93), G3 67.33% (52.40 – 82.26) [In contrast to the G1 compared to G2 and G3 P <0.05]. Inspiratory capacity (IC) in G1 was 76.90% (66.94–86.85), G2 102.04% (94.94–109 145), G3 115.72% (105.61–125.82) [G1 with significant difference compared with the G2 and G3 P < 0.05]. CONCLUSIONS: The morbidly obese have a lower FRC and ERV and increased IC and CV.