Respiratory muscle strength in obese individuals and influence of upper-body fat distribution

Sao Paulo Med J. 2007 Jul 5;125(4):215-9. doi: 10.1590/s1516-31802007000400004.


Context and objective: Pulmonary dysfunction in obese individuals may be associated with respiratory muscle impairment, and may be influenced by predominance of upper-body fat distribution. The objective of this study was to evaluate the strength of respiratory muscles in obese individuals and to analyze the influence of adipose tissue distribution.

Design and setting: Cross-sectional study on the preoperative period prior to bariatric surgery. Research developed within the Postgraduate General Surgery Program, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (Unesp).

Method: Respiratory muscle strength was quantified by measuring maximum inspiratory and expiratory pressures (PImax and PEmax) in obese candidates for bariatric surgery. Adipose tissue distribution was assessed using the waist-hip circumference ratio (WHR). PImax, PEmax and WHR were compared with normal reference values and also in groups with different body mass index (BMI).

Results: We evaluated 23 men and 76 women. All underwent PImax evaluation and 86 underwent PEmax. The mean BMI was 44.42 kg/m2. PImax and PEmax were within normal values; WHR showed that there was predominance of upper-body fat distribution; and there were no correlations among the variables studied. There was no significant variance among the variables PImax, PEmax and WHR when the study population was divided into groups with different BMI.

Conclusion: In the obese population studied, the excess weight did not result in impairment of respiratory muscle strength, and their predominant upper-body fat distribution also did not influence respiratory muscle strength.

MeSH terms

  • Adipose Tissue / physiopathology*
  • Adult
  • Analysis of Variance
  • Body Fat Distribution*
  • Body Mass Index
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Muscle Strength / physiology*
  • Obesity / pathology
  • Obesity / physiopathology*
  • Pulmonary Ventilation / physiology
  • Respiratory Muscles / physiology*
  • Spirometry
  • Waist-Hip Ratio