Change of respiratory functions, the STOP-Bang questionnaire, and Epworth sleepiness scale after bariatric surgery

Obesity is a highly morbid and fatal syndrome that reduces respiratory function. Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder in morbid obesity. Herein, we aimed to determine how respiratory function tests changed over time after bariatric surgery and to assess non-PSG (polysomnography) tests, namely STOP-Bang questionnaire and Epworth sleepiness tests, for predicting OSAS risk.

This retrospectively conducted study enrolled 35 patients who underwent bariatric surgery. Patients were divided into three groups formed on the basis of time passed after surgery (1, 2, or 3 years). Preoperative and postoperative respiratory function test parameters assessed by spirometry, body mass index (BMI), STOP-Bang questionnaire, and Epworth sleepiness test scores were recorded.

Twenty-four (68.6%) patients were female, 11 (31.4%) male. The mean age was 36.5±10.5 years. Postoperative weight loss of the study groups was 26% p=0.001, 23.6% p=0.002 and 25.9% p=0.005. Reductions in BMI were 32 kg/m2 p=0.001, 34.5 kg/m2 p=0.002, 35.8 kg/m2 p=0.005 respectively. Postoperative FVC (440 ml, 390 ml, 430 ml p = 0.005) and FEV1 (220 ml p = 0.005, 250 ml p = 0.004, 214 ml p = 0.005) increased in all three groups. STOP-Bang questionnaire and Epworth sleepiness scale scores significantly decreased after weight loss compared to preoperative period in all the study groups.

We showed that FVC and FEV1 increased in the short and long term after weight loss by bariatric surgery; we also found that STOP-Bang questionnaire and Epworth sleepiness scale scores decreased postoperatively. These tests may be helpful to assess OSAS risk before and after surgery.

Bariatric surgery, Obesity, Respiratory functions, STOP-Bang questionnaire and Epworth sleepiness test.