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Vol. 7, No. 5 / May 2008

Bariatric surgery for obesity:
Does it decrease mortality?

Dr. Xiong is assistant clinical professor, departments of internal medicine and psychiatry and behavioral sciences, University of California, Davis.

Medicine in Brief summarizes discoveries, clinical tests, or guidelines published in internal medicine literature that can affect psychiatric patients and practice. This information is intended to help you:

keep current with important developments in internal medicine

knowledgeably discuss these developments with medical colleagues

determine when to refer patients to a primary care physician or specialist

manage psychiatric issues while your patients undergo evaluation or treatment for a medical condition.

Many obese patients suffer from depression, bipolar disorder, panic disorder, personality disorders, or other psychiatric conditions.1 Morbidly obese patients searching for a lasting solution to their weight problems might seek a psychiatric evaluation for bariatric surgery. However, before giving the green light for the procedure, consider that a recent study questions if bariatric surgery decreases mortality in obese patients.

Clinical Point

Bariatric surgery patients had a higher long-term risk of dying from coronary artery disease and suicide than the general population


Most bariatric surgery practice guidelines require evaluation and treatment of comorbid psychiatric conditions such as eating disorders, depression, and substance use disorder, which can worsen postoperative outcomes. Indications for bariatric surgery include a body mass index (BMI) ≥40 kg/m2 or ≥35 kg/m2 with significant obesity-related comorbid medical conditions, such as diabetes (Table 3).

A large-scale epidemiologic study found that bariatric surgery patients had a higher long-term risk of dying from coronary artery disease and suicide than the general population (Table 4).2 Bariatric surgery patients also have a higher mortality rate than the general population, although they may have an absolute 1% survival advantage over closely matched obese patients who do not have the surgery.3 This advantage might disappear when selection bias is controlled, however, because patients who undergo surgery are more motivated to improve their health than patients who remain obese.

Table 3
Body mass index (BMI) values Obesity class
BMI

Underweight
<18.5 kg/m2

Normal
18.5 to 24.9 kg/m2

Overweight
25 to 29.9 kg/m2

Mild obesity
30 to 34.9 kg/m2

Moderate obesity
35 to 39.9 kg/m2

Morbid obesity
≥40 kg/m2

Of 16,683 bariatric operations performed in Pennsylvania over 10 years, 440 (2.6%) patients died. Nearly 1% of these deaths occurred within 30 days. The total death rate was approximately 1% per year and almost 6% at 5 years. In addition to the medical causes, 45 bariatric patients died from traumatic causes:

16 suicides (4%)

14 drug overdoses (3%)

10 motor vehicle accidents (2%)

3 homicides (0.7%)

2 falls (0.5%).

Women accounted for 10 of the 16 suicides (62.5%) and 12 of the 14 (85.7%) drug overdoses.

Principal Source: Omalu BI, Ives DG, Buhari AM, et al. Death rates and causes of death after bariatric surgery for Pennsylvania residents, 1995 to 2004. Arch Surg 2007; 142(10):923-8.

Discussant: Glen L. Xiong, MD

Treatment options. When treating obese patients, choose medications with a low risk for weight gain, which may include switching to a medication in the same class that is less likely to cause weight gain. Also, give patients educational handouts and resources about dietary and exercise regimens that focus on behavioral reinforcement. Although important, lifestyle modification and medication management produce nonsustained and modest results for most obese patients. Benefits are even more limited in morbidly obese patients with BMI ≥40 kg/m2.

Clinical Point

For most obese patients, lifestyle modification and medication management produce modest, nonsustained results


Bariatric surgery is an emerging treatment option for obese patients, although its use has been limited by safety concerns, availability, and lack of coverage by many insurance companies. Among obesity treatments, only bariatric surgery has demonstrated enduring weight loss and reduced medical comorbidities such as diabetes.4

Table 4
Leading medical causes of death after bariatric surgery
30-day mortality n = 150
Overall mortality* n = 395

Surgical complication
28 (25.3%)
45 (11.4%)

Pulmonary embolism
31 (20.7%)
47 (11.9%)

Coronary artery disease
26 (17.3%)
76 (19.2%)

Sepsis
17 (11.3%)
55 (13.9%)

* Up to 9 years of follow-up

Source:Reference 2

A new epidemic. The prevalence of obesity—nearly 1 in 3 Americans—has increased dramatically over the last few decades for reasons that include dietary indiscretion and sedentary lifestyle.5 Obesity is associated with decreased life expectancy,6 reduced quality of life, and higher incidence of diabetes, hypertension, arthritis, cardiovascular disease, sleep apnea, gastroesophageal reflux disease, and other chronic medical conditions. In addition, metabolic side effects of some psychotropic medications—especially antipsychotics—can exacerbate weight gain.

Practice Points

Do not recommend bariatric surgery for patients with unstable psychiatric symptoms and psychosocial conditions or those who cannot follow up with postoperative care and required lifestyle modifications.

Evaluate obese patients for psychiatric symptoms and suicidal thoughts because bariatric surgery patients may have an elevated risk of suicide.

Consider referring patients with a BMI≥40 kg/m2 or a ≥35 kg/m2 with significant obesity-related comorbid medical conditions for bariatric surgery.

Bariatric surgery patients have an increased risk of coronary disease-related adverse events, so refer bariatric surgery patients to primary care providers for follow-up.

Related resources

American Society for Bariatric Surgery. Pre-surgical psychological assessment of bariatric surgery candidates. www.asbs.org/html/pdf/PsychPreSurgicalAssessment.pdf.

National Heart Lung and Blood Institute. Body mass index calculator. www.nhlbisupport.com/bmi/bmicalc.htm.

Torpy JM, Burke A, Glass RM. JAMA patient page. Bariatric surgery. JAMA 2005;294;(15):1986. Available at: http://jama.ama-assn.org/cgi/reprint/294/15/1986.pdf.

Disclosure

Dr. Xiong reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

References
Pickering RP, Grant BF, Chou SP, Compton WM. Are overweight, obesity, and extreme obesity associated with psychopathology? Results from the national epidemiologic survey on alcohol and related conditions. J Clin Psychiatry 2007;68(7):998–1009.
Omalu BI, Ives DG, Buhari AM, et al. Death rates and causes of death after bariatric surgery for Pennsylvania residents, 1995 to 2004. Arch Surg 2007;142(10):923–8.
Livingston EH. Obesity, mortality, and bariatric surgery death rates. JAMA 2007;298(20):2406–8.
Sjöström L, Lindroos AK, Peltonen M, et al. Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. N Engl J Med 2004;351(26):2683–93.
Ogden CL, Carroll MD, Curtin LR, et al. Prevalence of overweight and obesity in the United States, 1999–2004. JAMA 2006;295:1549–55.
Grundy SM. Obesity, metabolic syndrome, and coronary atherosclerosis. Circulation 2002;105(23):2696–8.
Current Psychiatry ©2008 Dowden Health Media

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