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| Putting the squeeze on fat |
24-Aug-2006 |
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More carbs, fewer carbs, hypnotherapy, counselling
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obese patients have tried them all. Is bariatric surgery the magic bullet for a growing problem?
By Bianca Nogrady.
WHEN it comes to losing weight, surgery beats all other strategies hands down. What other method allows even the most intractably obese patients to shed 30-50% of their body weight and, for the most part, keep it off for at least 10 years?
Discovered almost by accident as a consequence of gastric surgery for ulcer disease and malignancy, weight-loss surgery is now the fastest-growing surgical procedure in Australia. In a decade the number of bariatric procedures performed each year has rocketed from fewer than 300 to about 5000. And, with increasing numbers of Australians categorised as morbidly obese, demand can only increase.
Despite the surgery’s extraordinary success, some experts are uneasy about such a drastic — albeit relatively safe — option becoming routine. The procedure, they say, is only addressing the symptoms of a broader societal problem rather than tackling the root causes — poor eating and exercise habits, easy availability of unhealthy food and government reluctance to take any action that might be seen as impinging on an individual’s right to put whatever they please into their mouth.
Still, most acknowledge that, for the morbidly obese, surgery may be the only real option. After years of trying to help obese patients lose weight, endocrinologist Professor Alex Cohen is the first to admit it is often very difficult, and sometimes impossible, to achieve success. “Once a person has accumulated a debt of fat cells, even though they empty them, they’re sitting there waiting to be replenished within days or weeks,” says Professor Cohen, president of the Diabetes Research Foundation of WA. “Something that acts as a headmaster over the body’s fat distribution is bound to be helpful.”
In Australia, by far the most popular surgical weight-loss procedure is laparoscopic adjustable gastric banding, in which a hollow silicone band filled with saline is placed around the stomach just above the lesser curvature, creating a small pouch with a narrow passageway to the lower part of the stomach. The size of the pouch restricts the person to an entree-sized portion of food at any one sitting. Patients who have the procedure on average lose 50-60% of their excess weight over two years.1 The band can be adjusted by simply adding or removing saline.
Lap banding now accounts for 90% of bariatric surgical procedures in Australia. Other surgical weight-loss options — such as gastric bypass, bilio-pancreative diversion and tube gastrectomy — are less common because they are more complex, invasive and risky.
The cut-off point for surgery used to be a BMI of 40, back when stomach stapling was more common, says Professor Paul O’Brien, emeritus professor of surgery at Melbourne’s Monash University. However, the cut-off BMI has fallen to 35 since the safer lap banding came into vogue. And the cut-off could be set to drop even further after a recent Australian study found lap banding was significantly more effective than non-surgical therapy in mild-to-moderate obesity — BMI 30-35 — and had similar rates of adverse events.2 Patients in the surgical group on average lost 87.2% of their excess weight compared with a loss of 21.8% in the non-surgical therapy group.
“It’s hard to say no to [someone with] a BMI of 32, because I know I could do better with surgery,” says Professor O’Brien, also director of Monash’s centre for obesity research and education. “At the moment, [the cut-off] is generally around 35 but I can see, as increasing recognition of safety and efficacy develops, the cut-off will come down to 30.”
The procedure is also becoming more common among adolescents, particularly as the incidence of obesity is rising faster in this age group than in any other. Although Professor O’Brien believes lap banding can be a life-changing procedure for obese teenagers, he draws the line at 14 years. “We wouldn’t treat anyone who we didn’t feel … understood what was going on, what they were getting themselves in for and what their role in making the procedure a success would be.”
This is because bariatric surgery is not an automatic ticket to weight loss. Post-surgical management is almost as important as the surgery itself, and requires the ongoing co-operation of the patient. Because they can only consume small amounts of food, patients must adopt a diet that ensures they get enough protein, carbohydrate and nutrients, while also being low in fat and sugar. Unfortunately, it is possible to ‘cheat’ the lap band by consuming high-sugar, high-fat foods or softer, more-liquid foods that pass easily through the stoma.
Nutritionist Dr Rosemary Stanton (PhD) is worried patients’ diets after surgery are not monitored closely enough, allowing some to continue the poor eating habits that contributed to their obesity in the first place. “In my experience, people don’t learn sensible eating habits — they just eat small amounts of ice-cream or chocolate,” Dr Stanton says. She is also concerned the small portion sizes reduce consumption of bulkier healthy foods such as fruit and vegetables. “We know the benefits of dietary fibre, yet most people [who have had surgery] are unable to eat good sources of dietary fibre.”
Sydney GP and obesity expert Dr Neil Peace is concerned that patients who have surgery don’t necessarily improve their fitness. “Research shows that patients who lose weight by bariatric surgery in the end are not as physically fit as patients who lose weight by conventional means of exercise and diet,” says Dr Peace, from the Sydney Medical Weight Loss Centre. “You still have the sedentary syndrome in which there are a lot of medical problems purely due to lack of exercise.”
Dr Stanton believes part of the problem is that most of the follow-up after lap banding is done by the surgeon, rather than a dietitian or GP, and patients may not necessarily tell their surgeon about problems such as frequent vomiting.
It’s a concern shared by Sydney GP Dr Linda Mann. “I certainly think that the companies that I come across that undertake it appear to take quite seriously their responsibility to look at the dietary and psychological approach for patients, which means the GP is completely left out of the loop,” she says. “Patients can apparently go to these places without a referral, so the whole thing could occur without me knowing.”
Professor O’Brien’s clinic has sought to address such concerns, taking a multidisciplinary approach that involves exercise therapists and dietitians as well as GPs, who he believes can play a key role in post-surgical management, including adjustment of the band. Follow-up includes regular measurement of metabolic and nutritional status, such as blood glucose levels, lipid profile, liver function, and iron, vitamin B12, folate, homocysteine and protein levels.3
While type 2 diabetes can go into remission after massive weight loss, Professor Cohen believes patients with the condition should still have their fasting blood glucose tested quarterly or at least every six months, even if they appear to have been ‘cured’.
“I’d be the first to agree that … there are quite a large number of people with type 2 diabetes whose condition is obliterated by bariatric surgery,” he says. “[However] I don’t believe that diabetes is cured by bariatric surgery. I believe that it is very extensively and adequately relieved.”
Whether relieved or cured, the experts generally acknowledge at least two-thirds of patients with type 2 diabetes experience spectacular improvement — which makes it all the more difficult for endocrinologist Professor Joe Proietto to understand why the lap banding device is not covered by Medicare. Installation and adjustment of the band attract a rebate, but public and some private patients must still pay about $3000 for the band itself. To make matters worse, waiting lists in public hospitals can now be as long as five years.
“It is beyond my understanding why it is, with all the evidence available that it’s cost-effective therapy for obesity, that governments cannot fund public bariatric surgery,” says Professor Proietto, from Austin Health and the University of Melbourne. “The waiting lists of the few hospitals that have the procedure run to 3-5 years because they have not received specific funding within the budget.”
Despite Dr Peace’s clinical focus on non-surgical weight loss, he also supports full government subsidisation of lap banding. “From a government and financial point of view, they’re going to save themselves an awful lot of money because the cost of these [obese] individuals later is horrendous — diabetes, hospitalisation, the cost is enormous.”
The Federal Health Minister’s office did not respond to a request for comment on the availability of lap banding for public patients.
But, as always when demand exceeds supply, private enterprise is rushing to pick up the slack. A thriving private industry is already marketing weight-loss surgery directly to the public — something Professor O’Brien is “horrified” by. “They’re just treating it like cosmetic surgery … This is the most powerful method of health care, yet it’s going to be misunderstood because of that.”
Bariatric surgery is certainly powerful, but most experts still see it as a last resort. Dr Peace would like to see more done at a legislative level to prevent obesity. “It’s very, very difficult for an individual to find a way to lose weight and keep it off, so I think any help at a societal level and cultural level is the way to go, and that’s only going to happen with legislation.”
A 20% tax on high-fat foods, restrictions on advertising and tax-breaks for fitness activities could all help, he believes.
Children are widely acknowledged to be particularly susceptible to marketing of unhealthy foods, prompting many experts to push for legislative change to protect them from such enticements. However, with Federal Health Minister Mr Tony Abbott recently stating on ABC TV’s Four Corners that “no one’s in charge of what is going into kids’ mouths except their parents”, the government appears to be in no hurry to take action.
References
1. Obesity Surgery Society of Australia and New Zealand: www.ossanz.com.au/lapband.asp
2. Annals of Internal Medicine 2006; 144:625-33.
3. www.medicineau.net.au/clinical/obesity/obesit3160.html
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