Obesity has been identified by the WHO as the world’s fastest growing health problem. In the US, it represents the 2nd most preventable cause of death next to cigarette smoking. It has been defined as a disease of chronic positive calorie balance.

Overweight and obesity are associated with numerous medical, mental and mobility problems known as co-morbidities of obesity. They are also associated with many social, workplace and marital problems.

Overweight and obese patients desire to become thin for various reasons- medical, cosmetic, to overcome discrimination, become well liked or to even save their marriages. Not all however can achieve this.

While a proportion have become obese from overindulgence, the remainder may have a genetic basis. They may have genes that allow deposition of fat even in the presence of a low calorie intake, they may have metabolisms that shut down aggressively when they begin a diet or they may have appetite centers that result in insatiable hunger. For various reasons, the overall success rate of non-surgical weight loss options is 2 - 5% at 5 years.

CLASSIFICATION
BMI has long been used as a measure of fatness. It is easy to calculate, does not require elaborate equipment and it can be measured as easily in a remote village as it can in an obesity centre. Its disadvantages are a lack of accuracy in children and inter-racial variation. The WHO traditionally defined overweight and obesity by BMI. It was recently shown however that for a given BMI, an Asian has the same % body fat and health risks as a Caucasian with a BMI 3 points higher. In 2001, the WHO suggested that Asian countries adopt a new set of BMI cut-off points.
                                           BMI (WHO)          BMI (Singapore)         

Overweight                              25-30                      23-27.5                       
Obesity                                  30-35                     27.5-32.5

Medically Dangerous Obesity
Clinically Severe Obesity         >35 (+co-morb*)      32.5-37.5 (+co-morb*)
Morbid obesity                        >40                        >37.5 

*co-morb: co-morbidities such as Osteoarthritis, Hypertension, GERD, Urinary stress, Incontinence, Gallbladder disease, Depression, Diabetes, Hyperinsulinemia, Asthma, Sleep apnea, Congestive heart failure, Anemia, Neoplasia, Dyslipidemia

By the old criteria, the incidences of overweight and obesity in Singapore were 29% and 6.9%. By the new criteria, they are about 14% and 35%.

MANAGEMENT

Normal BMI (< 23)
The first step is reassurance that they have a normal BMI. If the patient still wishes to lose weight, a 500 kcal deficit diet and an exercise regimen can be recommended. Most patients can safely lose 3-5 kg and will be satisfied with the results. Those who are still not satisfied probably have problem areas of fat such as under the chin, hips, thighs, abdomen, and excessively large breasts or in males, gynaecomastia. These patients may require liposuction, lipectomy, breast reduction or subcutaneous mastectomy for males. Finally, patients with a BMI < 18 seeking further weight loss may have anorexia or bulimia nervosa and should be referred for psychiatric evaluation.

Overweight (BMI 23-27.5)
In many cases the long term goal should be ‘no further weight gain’, especially if the patient is happy with his or her weight and there are no co-morbidities. The patient should be conscious of their calorie intake, avoid snacking and avoid high calorie and sweet foods. They should do regular exercise at least 3 times a week, each session lasting 30 min. and take up a new sport or hobby e.g. cycling, golf, tennis, swimming etc. Should they wish further weight loss, face pressure to lose weight or have co-morbidities, a 5 to 10% weight loss is recommended. (see Obesity below).

Obesity (BMI 27.5-32.5)
All obese patients should be encouraged to lose 5-10% of their body weight. Obesity poses a significant risk of co-morbidities such as diabetes, high blood pressure, hyperlipidaemia and premature death. A 5% weight loss will cure or improve 80% of co morbidities, even if normal weight is not achieved.

(A) First line- diet, exercise and behavior modification-
1.   Diet- 500 kcal deficit, low fat AHA diet
2.   Exercise- 30 min, 3 times a week at 60-70% of maximum heart rate (220 – AGE = your maximum heart rate)
3.   Behavior modification- healthy eating habits, increasing incidental activity, family support and a slimming buddy
4.   Treatment of co-morbidities and secondary causes
5.   Addition of a malabsorbtive drug such as Xenical or in diabetics, Metformin

 (B) Second line- Appetite suppressant. An appetite suppressant or hyper-metabolic drug e.g. Reductil, Duromine or Panbesy. These drugs have been found to be associated with strong rebound appetite and regain of weight after cessation; hence they should be prescribed in conjunction with dietary and exercise instructions. Reductil is approved for 2 years while Duromine and Panbesy for 6 mth. Patients can expect a 5-8 kg weight loss with Reductil and 5-10 kg with Duromine and Panbesy.

(C) Third Line- Intragastric balloon. Patients with obesity who have failed to lose weight by all other means may consider the intra-gastric balloon. (See below).

MEDICALLY DANGEROUS OBESITY (BMI > 32.5)

Medically dangerous obesity includes Clinically Severe Obesity or Severe Obesity (BMI 32.5-37.5) and Morbid Obesity (BMI > 37.5). The risk of co-morbidities, end organ damage and premature death are significantly higher than in obesity.

While the consequences of medically dangerous obesity are much more danggrave, the usual weight loss techniques are much less effective, in the order of 2% at 5 years. All weight loss techniques available to obese patients i.e. diet, exercise, behavior modification, drugs and the intra-gastric balloon are also available to these patients.

Patients with morbid obesity need to lose a large amount of weight and keep that weight permanently off. All the above weight loss techniques are available to them but long-term success of conservative methods and the intra-gastric balloon is extremely low at 5 yr. These patients have to lose a large amount of weight, often 30 or 40 kg to become healthy.

Patients with medically dangerous obesity who have failed to lose weight by other means or have lost and regained weight several times before should consider bariatric surgery (weight-loss surgery).

Bariatric Surgery is defined as operations of the stomach or intestines to help severely obese patients lose weight. They include stomach stapling, stomach bypass and Stomacg Banding (Lapband).

Lapband is the latest generation of bariatric operations. It is effective, laparoscopy friendly, adjustable and as it does not involve any resection or anastamosis, is the safest of the bariatric operations. 

A silicon band is laparoscopically placed around the upper part of the stomach to form a small upper pouch. When the patient eats a small amount of food, the pouch stretches and he or she feels full quickly. The upper pouch then takes several hours to empty through the constriction and into lower portion of the stomach, keeping the patient feeling full all this time.

The degree of constriction caused is adjustable by injecting saline into the band via a Port-a-cath type device deep under the skin. Adjustment is an office procedure under LA. In this way, daily caloric intake can be reduced by as much as 50%, resulting in a large 20-100 kg permanent weight loss. 

Lapband is performed by laparoscopy under GA and 90% of my patients stay just 1-night. The following day, they are ambulated and discharged. Pain is very much less compared to open surgery and patients may return to work after 3 – 7 days. The lapband needs to be adjusted by saline injection every 2 months until target weight is reached, usually in about 1 to 1½ yr. After that, visits are gradually stretched out to once a year.
           
Following surgery, the patients experience a feeling of fullness after eating just a little. This lack of hunger then goes on for several hours. This contrasts with the older stapling operations where the patient is unable to eat much but still feels hungry.  The reason is that lapband stretches the fundus of the stomach more than stapling and it is distension of the fundus more than any other part of the stomach that is responsible for the feeling of satiety.

Results  
Patients in my series of nearly 300 lapbands can expect to lose an average of 27 kg (114 kg preop to 87 kg at 1 year) in the 1st year and average BMI to drop from 42 to 33 kgm-2. This represents a 54% loss of excess body weight.
Eighty percent of patients with diabetes can expect cure or resolution after 1 year and 86% of hypertensives can expect cure or resolution after 1 year.

Criteria

1. BMI > 32.5 with co morbidities or BMI > 37.5, with or without co morbidities (Medically Dangerous Obesity)
2. Failed to lose weight by conservative means or lost but regained weight many times
3. Motivated and agreeable for the procedure

Advantages  

1. Large and Permanent weight loss
2. Laparoscopic (key-hole) operation - short stay, early return to work
3. Resolution of co-morbidities and increased life-expectancy
4. Latest and safest of the bariatric operations
5. Easily reversible

Disadvantages

1. Invasive procedure under GA
2. Cost

Conclusion
Medically Dangerous Obesity results in end-organ damage, suffering and premature death. Bariatric operations like lapband, while highly effective, also carry a tiny risk of mortality and morbidity. Statistically, at a BMI of 32.5 and beyond, the risks the obesity outweighs the risks of the surgery. Patients with Medically Dangerous Obesity need to lose a large amount of weight by any means, including surgery if necessary.

Lapband Position
The lapband placed high
up on the stomach

 

 

 

 

 

Before
97 kg, DM, Hpt

After 18 mth
64 kg, no DM, Hpt

 

 

 

 

           
The intra-gastric balloon is a silicon balloon inserted into the stomach under endoscopic guidance and inflated with saline to a volume of 400-700 ml. The inflation tube is then pulled out, a valve seals and the inflated balloon is left behind. The balloon is roughly 1/3 the volume of the stomach and results in early satiety. The balloon has to be removed before 6 mth. as it is subjected to gastric acid that can cause it to leak. Removal is also an endoscopic procedure. In this period, the patients will generally lose 7 – 15 kg. 
           
The usual complications are nausea and abdominal cramps in the 1st week while the stomach gets used to the mass. Rarely, in less than 1% of patients, the balloon can leak prematurely. It is usually passed out spontaneously but can occasionally result in intestinal obstruction if it gets jammed in the ileum.

Advantages
better weight loss than diet and exercise
less rebound appetite after removal

Disadvantages
cost
temporary nature
side effects

The Bioenterics Intragastric Balloon (BIB)

Review of Gastro-Esophageal Reflux Disease

Review of The Surgical Management Of Obesity

Benefits and Risks of Bariatric Surgery