Spirometric function improves in the morbidly obese after 1-year post-surgery

Obes Surg. 2010 Sep;20(9):1273-7. doi: 10.1007/s11695-010-0142-y.


Background: Obesity can negatively affect pulmonary function tests, with or without clinical symptoms, but the impact of bariatric weight loss is still debated. Aiming to document such profile in a consecutive homogeneous population, a prospective cohort study was undertaken.

Methods: Sixty-one patients (100% females, age 40 +/- 8 years, BMI 49 +/- 5 kg/m(2) and without respiratory disease) were enrolled. Spirometric analysis was carried out to compare preoperative respiratory pattern with outcome after 6 and 12 months. Variables included vital capacity (VC), expiratory reserve volume (ERV), forced expiratory volume (1 s) (FEV1), FEV1/FVC ratio and maximum voluntary ventilation (MVV). Correlation of results with weight loss was examined.

Results: The following initial variables exhibited significant difference when compared to the 12-month postoperative control: FVC (P = 0.0308), FEV1/FVC (P = 0.1998), MVV (P = 0.0004) and ERV (P = 0.2124). Recovery of FVC and FEV1/FVC occurred earlier by 6 months. The most seriously depressed preoperative finding was ERV, which even after 1 year still remained inadequate.

Conclusions: (1) Pulmonary limitations were diagnosed in approximately one third of the population. (2) Changes were demonstrated for FVC, FEV1/FVC, ERV and MVV. (3) FEV1 and FEV1/FVC were acceptable due to the absence of an obstructive pattern. (4) Two variables increased by 6 months (FEV1/FVC and ERV), whereas recovery for others was confirmed after 1 year. (5) The only exception was ERV which continued below the acceptable range.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Expiratory Reserve Volume
  • Female
  • Forced Expiratory Volume
  • Gastric Bypass*
  • Humans
  • Maximal Voluntary Ventilation
  • Obesity, Morbid / physiopathology
  • Obesity, Morbid / surgery*
  • Respiratory Function Tests*
  • Spirometry
  • Vital Capacity