With recent federal estimations that 36.5% of the U.S. adult population is obese, internists may be used to routinely counseling patients about losing the extra pounds. But telling patients with severe obesity to “eat less and move more” may not be enough of an intervention. For these patients, bariatric surgery may be an option.
Bariatric surgery induces weight loss primarily by restricting the size of the stomach, thereby reducing the amount of food a patient can consume. Patients with a body mass index (BMI) of 40 kg/m2 or greater, or a BMI between 35 and 39.9 kg/m2 and 1 or more serious comorbidity, are potential candidates for bariatric surgery, according to guidelines set in 1991 by the NIH Consensus Development Conference Panel. The 3 major comorbidities typically approved by insurance include type 2 diabetes, heart disease, and obstructive sleep apnea, although each insurance carrier may define these differently.
The prevalence of clinically severe obesity, defined as a BMI greater than 40 kg/m2, increased by about 70% from 2000 to 2010, affecting 6.6% of the U.S. adult population versus 3.9%, according to a 2013 report in the International Journal of Obesity. Yet fewer than 2% of eligible patients receive bariatric surgery each year.
One possible reason, said ACP Member Fatima Cody Stanford, MD, MPH, MPA, an internist and pediatrician specializing in obesity medicine, is that internists do not refer enough patients who may qualify for bariatric surgery. Too often, they assume that these patients haven't worked hard enough to achieve a healthy weight, but surgery could be the tool they need to finally succeed, she said.
“If that person has really tried all behavioral attempts and consistently struggles with their weight in a significant manner, then I think the idea of considering bariatric surgery needs to come into the mind of internists much sooner than it typically does,” said Dr. Stanford, who practices at the Massachusetts General Hospital Weight Center in Boston. And once a patient is referred for bariatric surgery, physicians must stay abreast of the major changes that occur in the immediate preoperative course, as well as the early and late postoperative course, she said.
Talking about options for weight loss starts with the primary care physician, who should have a longstanding relationship with the patient, said Eric I. Rosenberg, MD, MSPH, FACP, chief of the division of general internal medicine and associate professor at the University of Florida College of Medicine in Gainesville. “This discussion has to begin from a position of mutual trust,” he said.
To that end, be sure not to judge severely obese patients for how they look, Dr. Stanford recommended. “People could have basically any other medical issue, and you can't see it by looking at them, usually,” she said. “But with persons that carry the amount of weight that usually requires bariatric surgery, it's quite visible. You wear it.”
Physicians should also recognize that patients with severe obesity are unlikely to solve the problem on their own, Dr. Rosenberg said. “Many patients feel like the burden is on them alone, that if they only try harder or work harder or were more disciplined, they'd be able to lose the weight,” he said. “I try to reassure them that when you get to the point of having a BMI above 40, especially if you're battling diabetes, high blood pressure, and sleep apnea, you need an expert to help you.”
Although bariatric surgery is the treatment modality that is likely to be most efficacious in patients with high BMIs, it's important to try modalities that may lead to some preoperative weight loss, such as antiobesity medications, Dr. Stanford said. The 3 primary groups of these medications are centrally acting medications that impair dietary intake, medications that act peripherally to impair dietary absorption, and medications that increase energy expenditure. Examples of FDA-approved antiobesity medications include orlistat, combination phentermine and topiramate, and lorcaserin.
For patients who have exhausted all nonsurgical options, the first hurdle is bringing up bariatric surgery, said Dr. Rosenberg. The second is “addressing the anxiety associated with having surgery and perhaps the perception that this is a radical procedure, and one that has high complications,” he said.
The decision to have a bariatric procedure is a major one, so a patient may express that he or she doesn't want surgery or is afraid to have it. In these cases, Dr. Rosenberg said he would first try to gently determine the rationale for declining surgery and ensure that the patient and surgeon have had an opportunity to have a frank discussion about the particular surgery center's outcomes and complication rates. “I would acknowledge that many patients have had acquaintances who have undergone bariatric procedures and experienced complications, so I would not try to force the issue but instead revisit the topic periodically. ... The patient should feel fully supported in this decision and confident that it's the right one and right time to have surgery,” he said.
In general, high-volume surgery centers are most likely to have lower complication rates, so a community-based internist should refer patients to a center that performs many of these operations, Dr. Rosenberg said. It's also important to have a comfortable relationship with the surgeon and have an efficient communication channel between offices, he said.
If a patient is not being managed by a subspecialist, internists should check several lab tests before surgery, including a comprehensive metabolic panel, complete blood count, Helicobacter pylori, magnesium, phosphorus, parathyroid hormone, and vitamin B1, Dr. Stanford said. She said she also orders a hypercoagulation panel to see if a patient is predisposed to blood clots because obesity creates a higher likelihood of deep venous thrombosis or pulmonary embolism. Dr. Stanford said she also checks patients' thyroid function, electrolytes, and blood glucose control.
Physicians should also be aware of what they're doing to contribute to the obesity problem, she said, since drugs prescribed for other conditions, such as antipsychotics, antidepressants, sleep agents, beta-blockers, steroids, insulin, hypoglycemic agents, and neuropathic agents, can contribute to excess weight gain or inability to lose weight and could continue to do so after surgery.
“This is a very important point,” said Daniel Leslie, MD, director of bariatric surgery at the University of Minnesota in Minneapolis. “Sometimes much of the weight gain may be attributable to a medication; weight regain after surgery can be due to the same effect.”
When evaluating weight-promoting medications, an internist should first determine if each drug is necessary for an individual patient, Dr. Stanford said. If a drug is not deemed necessary, then the physician might consider stopping it altogether; if it is necessary, then the physician should work to prescribe the drug with the lowest effective dose, as weight gain from weight-promoting drugs may be dose-dependent, she said. Regarding the risk-benefit threshold for these drugs, an internist should ensure a patient's condition is being treated optimally with the lowest dose of as few weight-promoting medications as possible, Dr. Stanford said.
Perioperative concerns about comorbidities are a bit of a chicken-and-egg dilemma, said Dr. Rosenberg, who suggested confirming that patients' conditions are as controlled as possible prior to surgery in order to reduce the risk of complications. “The fact that they have those problems is the very justification for doing the surgery,” he said. “The task is to find out if things are as stable as they can be.”
Internists can do this through clinical assessment and certain markers that support stability, such as an HbA1c as close to 7% as possible in patients with diabetes, Dr. Rosenberg said, noting that physicians should recognize that one of the main contributors to better glycemic control is weight loss. In patients with suboptimal diabetes control, he said he looks for evidence of adherence to medications and blood glucose testing. Dr. Rosenberg said he also checks to see if a patient with diabetes has been educated on medications and diet, as well as if he or she has seen an endocrinologist preoperatively.
In the few weeks after surgery, internists should be thinking about medication adjustments and reductions, said Dr. Rosenberg. “The fun part for an internist is getting rid of medications and seeing that polypharmacy reduced, having discussions around reducing insulin dosages or even eliminating hypertensives, and watching the patient's appearance change dramatically as time goes on,” he said.
In the first 12 months after surgery, internists need to monitor patients' comorbidities very closely because many major changes happen, Dr. Stanford said. For example, patients with type 2 diabetes might no longer require insulin or the issue could resolve altogether, she said. Doctors should also be sure to send patients with obstructive sleep apnea back for a sleep evaluation; the condition often resolves after surgery, yet patients continue using unnecessary machines because they aren't retested, Dr. Stanford said.
Bariatric surgery has become a safer procedure, with mortality rates dropping significantly across the country from “above 1% more than 10 years ago to below 0.2% now,” said Dr. Leslie. Mortality from bariatric surgery is lower than mortality from cholecystectomy or routine hip surgery, he noted. However, internists shouldn't expect bariatric surgery to be a cure-all for patients' health problems. “A lot of times, people are referred with the pretense that all their comorbidities will resolve,” said Dr. Stanford. “Obviously, that's not always true.”
About 3 months after surgery, physicians should recheck preop labs, with the exception of the hypercoagulation panel and H. pylori test, Dr. Stanford said. They should also check the levels of vitamin B12, iron, vitamin D, and calcium to determine if there are any vitamin deficiencies, Dr. Leslie said. Even when patients are 10 years out of surgery, their vitamin and mineral levels must be monitored annually, according to Dr. Stanford.
“The bariatric surgery team should be integrally involved in evaluating and treating side effects from the procedures,” Dr. Leslie said. “For example, some patients can develop abdominal pain or painful swallowing, and these symptoms should be referred back to the bariatric surgery clinic for evaluation.” Side effects such as persistent nausea and vomiting may cause thiamine deficiency and Wernicke-Korsakoff syndrome, he said. In addition, the altered anatomy from bariatric surgery may make conventional treatments for abdominal pain and malnutrition more challenging, and vomiting associated with a prior adjustable gastric band procedure almost always requires bariatric surgery evaluation, Dr. Leslie noted.
Physicians should also encourage good hydration and be on the lookout for psychological changes, Dr. Stanford said. “It's well documented in the literature that postop patients may struggle with the adjustment that comes with losing that much weight and the postoperative course,” she said. “Make sure that if they need [a] psychiatrist or psychological care, they're referred appropriately.”
Internists should see patients periodically every 3 to 12 months, depending on how much intervention is needed. Patients usually attain their low point of weight loss within 12 to 18 months after surgery, Dr. Stanford said. “After that, they're treated very similarly to patients that have never had any type of surgery,” she said.
Keeping it off
Exercise can increase the likelihood of sustainable weight loss after bariatric surgery. For the first couple of months after surgery, Dr. Stanford recommends that patients exercise primarily by walking because there are so many metabolic changes happening. “And then you want to focus more on the quality of physical activity, the balance of strength, cardio, interval style training,” she said. “Because what we see in postop patients is that those who are more active have a higher likelihood of achieving weight maintenance and stability than those that aren't active.”
Plus, patients' bodies respond differently to bariatric surgery. In the case of 2 sisters who had weight loss operations, Dr. Stanford saw 2 different results. One sister lost 95% of her excess weight, whereas the other lost 20% of her excess weight, despite being more adherent to her doctor's orders.
“It shows that a lot of this is out of our control and it's just how the body responds,” said Dr. Stanford. “It's important to note that if a patient regains, it's not per se secondary to their lack of physical activity or poor diet quality; it just means that their body is trying to defend a higher set point for weight.” Especially with rapid weight regain after surgery, there may be some surgical or anatomical reason that might need to be addressed by the surgeon or an obesity medicine doctor, she said.
Despite the challenges associated with bariatric surgery, it can yield great benefits for patients, Dr. Leslie said, noting that he has a difficult time recognizing some of his patients 6 months after he performs their operations. And patients are often thrilled about the surgery's smaller effects, such as simply being able to tie their shoes independently or stand up unassisted, Dr. Rosenberg noted. “It's not so much the weight itself; it's what they're able to do that they couldn't do before,” he said.