Longitudinal effects of obesity on pulmonary function in obese children and adolescents.

BACKGROUND: To investigate the longitudinal effects of obesity on change in lung function after 1 year of follow-up in obese children and adolescents. METHODS: Obese children/adolescents aged 8-15 years with pulmonary function test (PFT) results and recorded anthropometric obesity indices from 1 year earlier for comparison were recruited. Multiple linear regression of change in each lung function parameter was applied to determine the effect of sex, change in body mass index (ΔBMI), change in chest circumference (ΔCC), change in waist circumference (ΔWC), and change in waist circumference-to-height ratio (ΔWC/Ht). RESULTS: Sixty-six children/adolescents (mean age: 12.5 ± 2.6 years) were recruited. Multiple linear regression analysis showed that ΔWC negatively affects the ratio of the forced expiratory volume in the first 1 s to the forced vital capacity of the lungs Δ(FEV1/FVC) (b = -0.3, p = 0.002), forced expiratory flow rate within 25-75% of vital capacity (ΔFEF25-75%) (b = -0.92, p = 0.006), and Δ(FEF25-75%/FVC) (b = -0.99, p = 0.003). When replacing ΔWC with Δ(WC/Ht) as the independent variable, Δ(WC/Ht) also negatively affects Δ(FEV1/FVC) (b = -33.71, p = 0.02), ΔFEF25-75% (b = -102.9, p = 0.03) and Δ(FEF25-75%/FVC) (b = -102.7, p = 0.03). CONCLUSION: After 1 year of follow-up, change in abdominal adiposity determined by WC and WC/Ht exerted significant negative effect on lung function change specific to FEV1/FVC, FEF25-75% /FVC, and FEF25-75%. IMPACT: Longitudinal effects of change in obesity on lung function in obese children and adolescents are evidenced. Change in waist circumference or waist-to-height ratio, which indicates abdominal adiposity, was inversely correlated with a change in FEV1/FVC, FEF25-75% /FVC, and FEF25-75% in children and adolescents with obesity after 1 year of follow-up. Our results suggest using waist circumference and/or waist-to-height ratio in addition to BW and/or BMI for monitoring obesity. Fat loss programs, especially those focused on reducing abdominal adiposity should be encouraged to prevent late lung function impairment.

Incidence and risk factors for long COVID in children with COVID-19 pneumonia.

BACKGROUND AND OBJECTIVE: There are only a few reports of long COVID including pulmonary function in children after COVID-19 pneumonia. We determined the incidence of long COVID and abnormal pulmonary function in those children and identify risk factors. METHODS: This cohort study enrolled children admitted with COVID-19 pneumonia during 2021-2022. We gathered clinical characteristics during admission and at follow-up 3 months after. RESULTS: We determined the incidence of long COVID at 39.7% (95% confidence interval [CI]: 30.7%-49.1%). All severe pneumonia cases consistently reported persistent symptoms. Exercise intolerance, cough, and fatigue were the three most common persistent symptoms in 26 (22.4%), 21 (18.1%), and 18 (15.5%) of the patients, respectively. At the follow-up, 21 cases (18.1%) demonstrated persistent abnormal chest radiographs. Three cases (6.9%) demonstrated restrictive ventilatory defects. Among those, one case (2.3%) demonstrated concomitant diffusion defect. Three cases (6.0%) demonstrated exercise-induced hypoxemia after the 6-minute walk test. Comparing spirometry variables between children with long COVID and without revealed significant difference of FEF25-75 (z score) between two groups. Age [adjusted OR (95% CI): 1.13 (1.05-1.22), p value 0.002], allergic diseases [adjusted OR (95% CI): 4.05 (1.36-12.06), p value 0.012], and living in polluted areas [adjusted OR (95% CI): 2.73 (1.18-6.33), p value 0.019] were significantly associated with long COVID. CONCLUSION: A significant percentage of children developed long COVID after COVID-19 pneumonia. We should give additional attention to those who have exercise intolerance, chronic cough, or fatigue, especially older children, severe cases, children with allergic diseases, and those living in polluted areas.

Effect of Threshold Inspiratory Muscle Training on Functional Fitness and Respiratory Muscle Strength Compared to Incentive Spirometry in Children and Adolescents With Obesity: A Randomized Controlled Trial.

Background: To determine the effect of threshold inspiratory muscle training (IMT) on functional fitness and respiratory muscle strength (RMS) compared to incentive spirometry (IS) in children/adolescents with obesity. Methods: A total of 60 obese children/adolescents aged 8-15 years were randomized into the threshold IMT group (n = 20), the IS group (n = 20), or the control group (n = 20). The IMT group performed 30 inspiratory breaths with the intensity set at 40% of baseline maximal inspiratory pressure (MIP) twice daily for 8 weeks; the IS group performed 30 breaths with sustained maximum inspiration twice daily for 8 weeks; and, the control group was assigned no training device for 8 weeks. Six-min walk test (6-MWT), RMS, and spirometry were compared between baseline and 8 weeks. Results: Six-MWT distance (528.5 ± 36.2 vs. 561.5 ± 35.2 m, p = 0.002) and MIP (121.2 ± 26.8 vs. 135.3 ± 32.1%Predicted, p = 0.03) were significantly improved after 8 weeks of IMT training. There was no significant difference in any evaluated pulmonary function parameters between baseline and 8 weeks in the IS or control groups; however, 6-MWT distance demonstrated a trend toward significant improvement in the IS group (526.9 ± 59.1 vs.549.0 ± 50.6 m, p = 0.10). No significant difference among groups was found for any variable relative to change from baseline to post-training. Conclusion: Eight weeks of threshold IMT training significantly improved both inspiratory muscle strength (MIP) and functional fitness (6-MWT) in children/adolescents with obesity. Eight weeks of IS training yielded a trend toward significantly improved functional fitness.

Obesity Indices for Predicting Functional Fitness in Children and Adolescents With Obesity.

Objectives: We aimed to determine the obesity indices that affect 6-min walk test (6-MWT) distance in children and adolescents with obesity and to compare the 6-MWT distance of obese subjects with that of normal-weight subjects. Methods: Obese children and adolescents aged 8-15 years and normal-weight age- and gender-matched controls were enrolled. All participants performed the 6-MWT; respiratory muscle strength (RMS), including maximal inspiratory pressure and maximal expiratory pressure; and spirometry. Data between groups were compared. In the obesity group, correlation between obesity indices and pulmonary function testing (6-MWT, RMS, and spirometry) was analyzed. Results: The study included 37 obese and 31 normal-weight participants. The following parameters were all significantly lower in the obesity group than in the normal-weight group: 6-MWT distance (472.1 ± 66.2 vs. 513.7 ± 72.9 m; p = 0.02), forced expiratory volume in one second/forced vital capacity (FEV1/FVC) (85.3 ± 6.7 vs. 90.8 ± 4.5%; p < 0.001), forced expiratory flow rate within 25-75% of vital capacity (FEF25-75%) (89.8 ± 23.1 vs. 100.4 ± 17.3 %predicted; p = 0.04), and peak expiratory flow (PEF) (81.2 ± 15 vs. 92.5 ± 19.6 %predicted; p = 0.01). The obesity indices that significantly correlated with 6-MWT distance in obese children and adolescents were waist circumference-to-height ratio (WC/Ht) (r = -0.51; p = 0.001), waist circumference (r = -0.39; p = 0.002), body mass index (BMI) (r = -0.36; p = 0.03), and chest circumference (r = -0.35; p = 0.04). WC/Ht was the only independent predictor of 6-MWT distance by multiple linear regression. Conclusions: Children and adolescents with obesity had a significantly shorter 6-MWT distance compared with normal-weight subjects. WC/Ht was the only independent predictor of 6-MWT distance in the obesity group.

Severe obesity is a risk factor for severe obstructive sleep apnea in obese children.

OBJECTIVE: To determine the association between degree of obesity and severity of OSA in Thai children MATERIAL AND METHOD: The present retrospective study recruited obese children aged 3 to 15 years who had habitual snoring and underwent polysomnography (PSG) between January 2009 and June 2010. Obesity was defined as percentage of ideal weight for height (%W/H) > or = 120 and was classified as mild (%W/H of 120-139), moderate (140-159), severe (160-199) and morbid (> or = 200). OSA was classified as severe (AHI > or = 10) and non-severe (AHI < 10). RESULTS: Of 73 obese children, the mean age was 9.92 +/- 3.42 years of which 60.3% were boys. The mean +/- SD of BMI was 28.38 +/- 5.99 kg/m2 and %W/H +/- SD was 162.63 +/- 26 26. Gender age, height, weight and BMI were not significantly different between severe and non-severe OSA groups. However, the %W/H of the severe OSA group (171.38% +/- 29.54%) was significantly greater than the non-severe group (157.19% +/- 22.68%) (p = 0.02). Severe to morbid obesity (OR 2.80, 95% CI 1.06-7.42; p = 0.038) and enlarged tonsils at least 3+ (OR 3.28, 95% CI 1.22-8.81; p = 0.018) were the risk factors for severe OSA. CONCLUSION: Severe to morbid obesity was a predicting factor for severe OSA. These results suggested that severely obese children with snoring should have early recognition for severe OSA, which is highly contributing to multiple sequalae.

Clinical presentation and lung function of children hospitalized with 2009 pandemic influenza A (H1N1) pneumonia.

To determine the clinical presentation and subsequent lung function following pneumonia caused by 2009 pandemic influenza A (H1N1), pH1N1, in children aged 5-15 years hospitalized from June to September 2009, we contacted patients meeting the criterion 3-6 months post-hospitalization. Of the 88 patients contacted, 31 (35.2%) had pH1N1 and 57 (64.8%) had infections due to other viral pathogens (non-pH1N1), the mean age was 10.4 years and 52 (59%) were boys. Compared to non-pH1N1 patients, the pH1N1 patients were more likely to have a high fever (96.8% vs 77.2%, p = 0.03), sore throat (58.1% vs 33.3%, p = 0.03), and injected pharynx (80.6% vs 40.4%, p = 0.001). At 3-6 months after pneumonia onset, means for FVC, FEV1, FEV1/FVC, FEF25-75%, and PEF were within normal limit in both the pH1N1 and non-pH1N1 groups. Five (28%) of 18 pH1N1 children and 4 (20%) of 20 non-pH1N1 children had abnormal lung function results. All were restrictive type. In conclusion, pH1N1 pneumonia were more likely to present with high fever, sore throat, and pharyngeal injection than pneumonia from other viruses. About one quarter of the children who had pH1N1 had restrictive lung function 3-6 months after infection. This number did not differ from the non-pH1N1 group.