This research is created for compare the difference of AHI variation between LSG and combined surgery on obstructive sleep apnea in obese patients , evaluate the risk of combined surgery and explore the correlative factor of the curative effect.

Obesity is one of the new health challenges in China and all over the world，Morbidly obesity (MO) is an important risk factor for metabolic diseases and obstructive sleep apnea(OSA), which can be effectively and lastingly reduced by bariatric surgery.

OSA is the most common type of sleep apnea and is caused by complete or partial obstructions of the upper airway. It is characterized by repetitive episodes of shallow or paused breathing during sleep, and is a potentially fatal disease. OSA has complex pathogenesis and numerous pathogeny, while morbidly obesity is one of the important risk factors of OSA. Previous research has shown that the incidence of OSA will rise by 1.14 % while body mass index(BMI) rise by 1%.Therefor, loseing weight is highly recommend for morbidly obese patients with OSA in clinical guideline for OSA both in USA and China, and bariatric surgery is effective for morbidly obese patients with OSA. Most yellow race morbidly obesity patients have abdominal obesity which is different from the white race，while Abdominal obesity is associated with greater incidence and more severely of OSA. There are maybe twenty million patients with OSA and 80% of them haven't been diagnosed.

At present,. Laparoscopic sleeve gastrectomy(LSG) and laparoscopic Roux-en-Y gastric bypass(LRYGB) are two of the main bariatric surgical procedures performed in China. They can performed as one stage each or multiple sessions(LSG-LRYGB) which is depend on the severity of obesity and its complications.

UPPP was first performed in 1981 by doctor Fujita and modified these years, it has been a standardized treatment for OSA. The effective rate of UPPP is less than 65% and is associated with the BMI and age of patients , younger and lower BMI means better effect. Consideration of the discontented outcome in obese patients, Simple UPPP is not recommended for OSA patients with morbidly obesity in clinical guidelines for OSA.

Although simple LSG has a sure prostecdtive efficacy for both OSA and morbidly obesity, patients still need CPAP during several months after surgery. So we chosed patients who conformed the surgical indications of both morbidly obesity and OSA，and performed an combined surgery (LSG+UPPP+adenoidectomy/tonsillectomy). We found that combined surgery has a better short-term efficacy than simple LSG, so the randomized clinical trial(RCT) was designed to explore the efficacy of combined surgery in the treatment of severe OSA in moderate-to-severe obese patients.

Inclusion Criteria:

1. Chinese Han population aged 16 to 65 years
2. BMI more than 32.5Kg/㎡ with AHI more than ≥30/hour
3. First diagnosed with PSG without any corresponding treatment;
4. Adenoid tonsil hypertrophy (Friedman stage II-III).

Exclusion Criteria:

1. Drug abuse, alcohol addiction and mental diseases
2. Dysgnosia
3. Over-high expectation
4. Risk-averse patient;
5. Poor tolerance to surgery
6. Patient suffering from gastroesophageal reflux and hiatal hernia
7. Central or mixed sleep apnea diagnosed by PSG
8. PO2<60mmHg when the patient is awake
9. Suffering from maligent tumor, neural system injury and respiratory insufficiency
10. Hypothyroidism
11. Other special issue decided by specialist.