Pulmonary function in overweight and obese children aged 6-12 years: a hospital and school-based observational study

Background: Childhood overweight and obesity may adversely influence respiratory mechanics and pulmonary function through mechanical restriction of the chest wall, altered diaphragmatic excursion, and changes in lung volumes. This study aimed to assess pulmonary function among overweight and obese children aged 6 to 12 years and compare spirometric parameters between BMI categories. Methods: A hospital-and school-based observational study was conducted among 45 overweight and obese children aged 6 to 12 years at Government Medical College and Hospital, Cuddalore District, Tamil Nadu, and selected schools in the district from December 2024 to May 2026. Baseline demographic and anthropometric characteristics were recorded. Pulmonary function was assessed using spirometry, including peak expiratory flow rate (PEFR), forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio. Observed values were compared with normal predicted values derived using Chhabra equations, and pulmonary function parameters were compared between overweight and obese children. Data were analysed using SPSS version 26.0. Results: The mean age was 10.31±0.90 years, and the mean BMI was 22.13±3.08 kg/m². Of the 45 participants, 21 (46.7%) were overweight and 24 (53.3%) were obese. The mean PEFR, FEV₁, and FVC were 3.74±0.96 L/s, 1.37±0.36 L, and 1.36±0.37 L, respectively. Their corresponding mean percentage predicted values were 69.82±21.62, 53.71±13.06, and 48.43±12.55. The mean FEV₁/FVC percentage predicted remained preserved at 107.52±2.56. Obese children showed slightly higher absolute spirometric values than overweight children. Conclusions: Overweight and obese children demonstrated reduced PEFR, FEV₁, and FVC compared with predicted normal values, while the FEV₁/FVC ratio remained preserved. Early pulmonary assessment and appropriate weight-management interventions may help reduce long-term respiratory consequences.