Which patients benefit most from bariatric surgery in the long term?

More than one-third of adults in the United States live with obesity. Currently, the most effective treatment for obesity is weight loss surgery, also known as bariatric surgery. At Geisinger, approximately 300 patients undergo bariatric surgery annually.

Bariatric surgery patients are expected to lose 30 to 40 percent of their body weight, but not all patients are able to lose this amount of weight and others experience weight regain. Why some patients succeed in weight loss over time, while others are less successful, remains unclear.

In a study recently published in JAMA Surgery, Geisinger Obesity Institute (OI) researchers evaluated over 200 patient characteristics in relation to long-term weight loss after bariatric surgery (7 years or longer), including gender, age and weight at the time of surgery, lab tests, medical conditions and medications, among others. OI researchers found that patients who used insulin, had a history of smoking, or used 12 or more medications before surgery lost the most weight, while patients with high cholesterol, older patients and patients with higher body mass indexes at the time of surgery lost the least amount of weight after surgery.

Possible explanations for the finding that patients taking the most medications before surgery, or those using insulin, had better weight loss are their greater interaction with health care professionals needed to manage these conditions or perhaps unintentional weight loss related to health conditions. Patients using insulin also need to manage their diet carefully to keep their diabetes under control, which may also assist in maintain weight loss after surgery. These study results can help to guide clinical care and to improve patient discussions about bariatric surgery as an obesity treatment option.

Geisinger's robust electronic medical record (EMR) and extensive bariatric surgery research database of patients followed for up to 12 years after surgery provided OI investigators the opportunity to evaluate these research questions.