Article Text

Download PDFPDF

The effects of obesity on pulmonary function
  1. A M Li1,
  2. D Chan1,
  3. E Wong2,
  4. J Yin1,
  5. E A S Nelson1,
  6. T F Fok1
  1. 1Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
  2. 2Centre for Clinical Trials and Epidemiological Research, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
  1. Correspondence to:
    Dr A M Li, Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR;
    albertmli{at}cuhk.edu.hk

Abstract

Aims: (1) To determine the predominant pulmonary function abnormality in our population of obese children; and (2) to assess the correlation between the severity of lung function impairment and the degree of obesity as assessed by dual energy x ray absorptiometry (DEXA).

Methods: Sixty four obese patients underwent physical examination, standardised pulmonary function tests (spirometry, lung volumes, and single breath diffusion capacity for carbon monoxide), and DEXA scan measurements. The trunk and subtotal (total − head) body fat mass were used as surrogate index of body adiposity.

Results: Sixteen girls and 48 boys with median age and body mass index (BMI) of 12 years (interquartile range (IQR): 10–14) and 30.1 kg/m2 (IQR: 27.2–32.8) respectively were studied. None of the patients had clinical evidence of cardiopulmonary disease. Reduction in functional residual capacity (median FRC 93% predicted, IQR: 68.5–116.5%) and impairment of diffusion capacity (median DLco 83.5% predicted, IQR: 70.0–100.7%) were the most common abnormalities in our cohort, being observed in 30 (46%) and 21 (33%) patients respectively. Obstructive ventilatory impairment was found in three patients. There was significant negative correlation between the degree of reduction of FRC but not DLco with DEXA scan measurements, but such a relation was not found when BMI was used as the indicator of obesity.

Conclusion: Reduction in FRC and diffusion impairment were the commonest abnormalities found in our cohort of obese patients. Reduction in static lung volume was correlated with the degree of obesity.

  • pulmonary function test
  • obesity
  • dual energy X-ray absorptiometry
  • BMI, body mass index
  • DEXA, dual energy x ray absorptiometry
  • Dlco, diffusion capacity of the lung
  • FEV1, forced expiratory volume in one second
  • FRC, functional residual capacity
  • FVC, forced vital capacity
  • IQR, interquartile range
  • MMEFR, maximum mid-expiratory flow rate
  • MVV, maximum voluntary ventilation
  • RV, residual volume
  • TLC, total lung capacity
View Full Text

Statistics from Altmetric.com

Footnotes

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.