Objective:To investigate the clinical efficacy of laparoscopic sleeve gastrectomy (LSG) for obesity complicated with obstructive sleep apnea syndrome (OSAS).Methods:The retrospective and descriptive study was conducted. The clinical data of 74 patients with obesity complicated with OSAS who were admitted to People's Hospital of Xinjiang Uygur Autonomous Region from January 2017 to June 2018 were collected. There were 40 males and 34 females, aged (39±10)years, with a range from 20 to 56 years. Observation indicators: (1) surgical and postoperative situations; (2) follow-up; (3) correlation analysis between obesity indicators and OSAS indicators; (4) analysis of factors influencing the postoperative efficacy of OSAS. Follow-up using hospitalization examination was conducted to detect the incidence of complications and the improvement of obesity and OSAS indicators after patients discharge. The follow-up was up to June 2019. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M (range). Count data were described as absolute numbers or percentages. Repeated measurement data was analyzed using the mixed-effects model. Correlation analysis was conducted using the Pearson correlation coefficients. Multivariate analysis was conducted using the COX proportional risk regression model. Results:(1) Surgical and postoperative situations: 74 patients underwent LSG successfully, without conversion to open surgery, including 12 cases undergoing LSG combined with laparoscopic cholecystectomy and 9 cases undergoing LSG combined with esophageal hiatal hernia repair. The operation time and volume of intraoperative blood loss of 74 patients were (88±22)minutes and (57±25)mL. There was no severe postoperative complications and perioperative mortality. The duration of postoperative hospital stay of 74 patients were 5 days (range, 3-8 days). (2) Follow-up: among 74 patients, 71 were followed up at 1 month, 68 were followed up at 3 months, 64 were followed up at 6 months and 61 were followed up at 12 months after operation, respectively. The body mass, body mass index (BMI), abdominal circumference, chest circumference, neck circumference, apnea hypopnea index (AHI), average oxyhemoglobin saturation (ASaO 2), lowest oxygen saturation, epworth sleepiness scale score, excess weight loss rate of the 71 patients who were followed up at 1 month after operation were (108±16)kg, (38±5)kg/m 2, (121±14)cm, (122±13)cm, (41.3±2.5)cm, (25±15)times/hour, 88.1%±3.8%, 70.0%±9.3%, 17.8±2.3, 30%±8%, respectively. The above indicators of the 68 patients who were followed up at 3 month after operation were (96±14)kg, (33±5)kg/m 2, (113±13)cm, (120±12)cm, (39.7±2.3)cm, (17±11)times/hour, 90.2%±3.1%, 78.5%±7.1%, 15.0±2.2, 52%±13%, respectively. The above indicators of the 64 patients who were followed up at 6 month after operation were (88±11)kg, (31±4)kg/m 2, (105±11)cm, (113±11)cm, (37.5±1.7)cm, (10±7)times/hour, 92.4%±2.2%, 84.2%±3.5%, 13.6±1.7, 63%±14%, respectively. The above indicators of the 61 patients who were followed up at 12 month after operation were (80±8)kg, (28±3)kg/m 2, (97±8)cm, (108±10)cm, (36.5±1.4)cm, (6±4)times/hour, 93.7%±1.4%, 88.0%±3.1%, 9.2±1.5, 75%±16%, respectively. There were significant differences in the body mass, BMI, abdominal circumference, chest circumference, neck circumference, AHI, ASaO 2, lowest oxygen saturation, epworth sleepiness scale score of patients before and after operation ( F=109.855, 108.632, 90.565, 27.846, 96.353, 49.969, 48.561, 115.938, 257.762, P<0.05). There were 39 cases with AHI<5 times/hour in the 61 patients who were followed up at 12 month after operation, and the clinical complete response rate of OSAS was 63.93%(39/61). (3) Correlation analysis between obesity indicators and OSAS indicators: results of the Pearson correlation analysis showed that the AHI was positively correlated with the body mass and BMI ( r=0.267, 0.317, P<0.05) and negatively correlated with the ASaO 2 and lowest oxygen saturation ( r=-0.525, -0.551, P<0.05), and there was no correlation between AHI and neck circumference ( P>0.05) in the 74 patients before operation. The lowest oxygen saturation was negatively correlated with the body mass and BMI ( r=-0.330, -0.400, P<0.05), and there was no correlation between lowest oxygen saturation and neck circumference ( P>0.05) in the 74 patients before operation. The AHI was negatively correlated with the ASaO 2 and lowest oxygen saturation ( r=-0.406, -0.373, P<0.05), and there was no correlation between AHI and the body mass, BMI or neck circumference ( P>0.05) in the 61 patients who were followed up at 12 month after operation. There was no correlation between lowest oxygen saturation and the body mass, BMI or neck circumference ( P>0.05) in the 61 patients who were followed up at 12 month after operation. (4) Analysis of factors influencing the postoperative efficacy of OSAS: results of the multivariate analysis showed that preoperative AHI was an independent influence factor for postoperative efficacy of OSAS ( hazard ratio=1.039, 95% confidence interval: 1.016-1.063, P<0.05). Conclusion:LSG can effectively reduce the body mass and improve OSAS of patients with obesity complicated with OSAS in the short term.