Weight loss, improvement in comorbid conditions after laparoscopic sleeve gastrectomy appear to decline with time, study finds

Bariatric surgery with laparoscopic sleeve gastrectomy (LSG) improves weight loss and comorbid conditions related to obesity in the short term, but its effects decline over the long term, according to a new study.

To examine the long-term effects of LSG, an increasingly popular bariatric surgery procedure, researchers performed a retrospective analysis of a prospective cohort at a university hospital. Patients who had LSG done by the same surgical team between April 1, 2006, and Feb. 28, 2013, were included. Researchers collected data on demographics, weight, results of blood tests, medications, and comorbid conditions, including diabetes, hypertension, hypercholesterolemia, hypertriglyceridemia, and hyperuricemia. The study's main outcome measures were excess weight loss and remission of obesity-related comorbid conditions at 1, 3, and 5 years of follow-up. The study results were published online Aug. 5 by JAMA Surgery.

In the study time period, 443 LSGs were performed, with complete data available on 241 of 443 patients (54.4%) at 1 year, 128 of 259 patients (49.4%) at 3 years, and 39 of 56 patients (69.6%) at 5 years. Before having surgery, 82 patients had been diagnosed with type 2 diabetes, 65 had been diagnosed with impaired fasting glucose, 110 had been diagnosed with hypertension, 155 had been diagnosed with hypercholesterolemia, 109 had been diagnosed with hypertriglyceridemia, and 55 had been diagnosed with hyperuricemia. Mean preoperative body mass index was 43.9 kg/m².

At 1, 3, and 5 years, the percentage of patients who had maintained their loss of excess weight was 76.8%, 69.7%, and 56.1%. Complete diabetes remission was maintained in 50.7%, 69.7%, and 56.1% at 1, 3, and 5 years, and hypertension remission was maintained in 46.3%, 48.0%, and 45.5%, respectively. Changes in HDL cholesterol levels and triglyceride levels were significant compared with pre- and postoperative measurements (P<0.001), but change in LDL cholesterol level was significant only at 1 and 3 years (P=0.04 for both comparisons), and changes in total cholesterol level were not statistically significant at any time point. Most of the changes in comorbid conditions did not correlate with percentage of excess weight loss.

The authors noted that patients lost to follow-up may have biased the results, that follow-up data were not all continuous, and that the sample size at the 5-year time point was small. However, they concluded that in patients who underwent bariatric surgery with LSG, the percentage of excess weight loss decreased over time, as did remission rates for type 2 diabetes, although these variables did improve in the short term. “These data should be taken into consideration in the decision-making process for the most appropriate operation for a given obese patient,” they concluded.

The author of an accompanying invited commentary pointed out that comparative trials of bariatric surgery procedures are lacking and that critical knowledge gaps exist. The current researchers, she noted, “clearly raise more questions than they answer,” given their study's limitations. She called for large-scale trials, further use of electronic databases, and pooled analyses to help solve the problems inherent in bariatric surgery research.

“It will take time, patience, and a willingness to avoid a rush to avoid a rush to judgment,” the commentary author wrote. “In the meantime, clinicians and prospective patients will need to discuss and weight the evidence in a dynamic exchange driven not always by final conclusions but by the most current available data.”