Increased exercise capacity after surgically induced weight loss in morbid obesity.
OBJECTIVE
To investigate the effects of surgically induced weight loss on exercise capacity in patients with morbid obesity (MO).


METHODS
A prospective 1-year follow-up study was carried out, with patients being their own controls. A symptom-limited cardiopulmonary exercise stress test was performed in 31 MO patients (BMI > 40 kg/m2) before and 1 year after undergoing bariatric surgery.


RESULTS
At 1 year after surgery, weight was reduced from 146 +/- 33 to 95 +/- 19 kg (p < 0.001), and BMI went from 51 +/- 4 to 33 +/- 6 kg/m2 (p < 0.001). After weight loss, obese patients performed each workload with lower oxygen consumption, heart rate, systolic arterial pressure, and ventilatory volume (p < 0.001). This reduced energy expenditure allowed them to increase the duration of their effort test from 13.8 +/- 3.8 to 21 +/- 4.2 minutes (p < 0.001). Upon finishing the exercise, MO patients before surgery were able to reach only 83% of their age-predicted maximal heart rate, and their respiratory exchange ratio was 0.87 +/- 0.06. After weight loss, those values were 90% and 1 +/- 0.08, respectively (p < 0.01). When we compared the peak O2 pulse corrected by fat free mass before and after surgery, no significant differences between the groups were found.


CONCLUSIONS
After surgically induced weight loss, MO patients markedly improved their exercise capacity. This is due to the fact that they were able to perform the external work with lower energy expenditure and also to increase cardiovascular stress, optimizing the use of cardiac reserve. There were no differences in cardiac function before and after surgery.
Cardiology Department, Hospital Universitario Germans Trias I Pujol, Universidad Autonoma de Barcelona, Badalona, Spain. lseres.germanstrias@gencat.net
Luis
L
Serés
Jordi
J
Lopez-Ayerbe
Ramón
R
Coll
Oriol
O
Rodriguez
Juan
J
Vila
Xavier
X
Formiguera
Antonio
A
Alastrue
Miguel
M
Rull
Vicente
V
Valle
D000328:Adult; D050110:Bariatric Surgery; D016009:Chi-Square Distribution; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery* / Q000628:therapy; D010101:Oxygen Consumption; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*