Bariatric surgery is superior to lifestyle intervention alone

By Owen Haskins

Bariatric surgery is superior to lifestyle intervention alone for the remission of T2DM in obese individuals including those with a BMI30-35 after three years, according to the results of a clinical trial and paper, ‘Three-Year Outcomes of Bariatric Surgery vs Lifestyle Intervention for Type 2 Diabetes Mellitus Treatment: A Randomized Clinical Trial, published in JAMA Surgery. Although the authors acknowledge that the trial provides valuable insights, some unanswered questions remain such as the impact of these treatments on long-term microvascular and macrovascular complications and the precise mechanisms by which bariatric surgical procedures induce their effects.

The trial researchers led by Dr Anita P Courcoulas of the University of Pittsburgh Medical Center, Pittsburgh, state whether bariatric surgery is a durable and effective treatment for type 2 diabetes (T2DM) and how bariatric surgery compares with intensive lifestyle modification and medication management with respect to T2DM-related outcomes, remains to be seen.

As a result, they established a three–arm randomised controlled trial that compared the efficacy for treating T2DM of two surgical procedures (RYGB and LAGB) plus LLLI in years two and three of follow-up with intensive LWLI in year one followed by two years of LLLI. Adults aged 25 to 55 years with a BMI of 30-40 were eligible and the diagnosis of T2DM was confirmed by fasting plasma glucose (FPG) level of greater than 125 mg/dL (to convert to millimoles per liter, multiply by 0.0555) and/or treatment with glucose-lowering medications.

In total, 61 individuals who were treated (20 with RYGB, 21 with LAGB, and 20 with LWLI) were invited to participate for two more years with annual visits and the addition of structured LLLI for all three treatment groups (RYGB + LLLI, LAGB + LLLI, and LWLI + LLLI). The LLLI for all three treatment groups consisted of twice-monthly contact (1 in-person session [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][approximately 30-45 minutes] and 1 brief [<10 minutes] telephone contact) and regular refresher group series.

Of the 61 participants who underwent treatment, 52 (85% overall; 18 [90%] with RYGB, 20 [95%] with LAGB, and 14 [70%] with LWLI) were evaluated for the assessments of 3-year safety and efficacy. Of the 52 participants included in the 3-year analyses, 82% were women and 79% were white. The mean (SD) values were 47.3 (6.6) years for age, 35.7 (3.1)for BMI, and 100.5 (13.7) kg for baseline weight; 26 participants (43%) had class I obesity (BMI<35). The mean (SD) values were 7.8% (1.9%) for baseline HbA1c level, 171.3 (72.5) mg/dL for FPG level, and 6.5 (4.8) years for duration of T2DM. Higher percentages of individuals in the RYGB group had insulin requirements at baseline (RYGB, 50%; LAGB, 38%; and LWLI 30%; P = .01) and the RYGB group had a significantly higher baseline HbA1c level than LWLI (mean [SD]: RYGB, 8.6% [2.1%]; LAGB, 7.9% [2.2%]; and LWLI, 7.0% [0.8%]; overall P = .03; RYGB vs LWLI P = .01).


At three years, any T2DM remission (partial or complete) was achieved in 40% (n = 8) of RYGB, 29% (n = 6) of LAGB, and no LWLI (P = .004) participants, while complete remission was achieved in 15% (n = 3) of RYGB, 5% (n = 1) of LAGB, and no LWLI group participants (P = .21). Continuous, sustained (any; partial or complete) remission for at least 2 consecutive years of the 3-year follow-up period was observed in 45% (n = 9) of RYGB and 29% (n = 6) of LAGB patients (Figure 1). There was a decline in any remission among RYGB participants from 60% at year one to 45% at year two and 40% at year three, whereas any remission for LAGB participants remained stable at 29% and none for LWLI over the 3-year period (P = .09).

Figure 1 li vs bs

Partial remission of type 2 diabetes mellitus included no use of antidiabetics, haemoglobin A1c level of less than 6.5% (to convert to proportion of total haemoglobin, multiply by 0.01), and fasting plasma glucose level of 125 mg/dL or less (to convert to millimoles per liter, multiply by 0.0555). Complete remission of type 2 diabetes mellitus included no use of antidiabetics, hemoglobin A1c level of less than 5.7%, and fasting plasma glucose level of 100 mg/dL or less. Missing data at follow-up were assumed to be no remission. The test of the difference between treatment group P values are calculated for each point as follows: year 1, P < .001; year 2, P < .001; and year 3, P = .004. LAGB indicates laparoscopic adjustable gastric banding; LWLI, lifestyle weight loss intervention (intensive); and RYGB, Roux-en-Y gastric bypass.

After three years, each of the surgical procedures plus LLLI was superior to lifestyle intervention alone (LWLI + LLLI) in achieving glycemic control. The RYGB group had the greatest change in both HbA1c (mean [SD], −1.42% [0.34%]) and FPG (−66.0 [10.94] mg/dL) levels from baseline to 3 years (HbA1c level, P < .0013 for RYGB vs LWLI; FPG, P < .05 for RYGB vs both LAGB and LWLI) (Table). The LAGB group showed improved HbA1c levels, averaging −0.80% (0.32%) at 3 years (P = .04 for LAGB vs LWLI) and FPG levels improved a mean (SD) of −35.2 (10.47) mg/dL (P = .67). Also examined were the changes in HbA1c and FPG levels over time by class (I and II) of obesity. For both measures, there were no significant interactions between obesity class and treatment groups, indicating that the patterns over time between treatment groups did not differ significantly by class of obesity. The use of diabetes medications was reduced more in the surgical groups than the lifestyle-alone group; with 65% of RYGB, 33% of LAGB, and 0% of LWLI participants going from using insulin or oral medication at baseline to no medication at year 3 (P < .001). Therefore, at 3 years, those in the RYGB group had the largest percentage of individuals (72%) not requiring any medications for T2DM compared with those in the LAGB (45%) and LWLI (0%) groups (P < .001).

At three years, modelled reductions in body weight, BMI, and waist circumference were greater after RYGB and LAGB than after lifestyle treatment alone (Figure 2). The percentage of reduction in body weight was also greater after RYGB than after LAGB (P = .0002).

There were no complications reported in the LWLI group at any point up to three years and no additional surgical interventions in either of the two surgical groups after year one of follow-up.

“The results of this study show that RYGB + LLLI and LAGB+LLLI are superior to lifestyle treatment alone for T2DM remission and other glycemic control end points at 3 years…More than two-thirds of those in the RYGB group and nearly half of the LAGB group did not require any medications for T2DM treatment at three years,” the authors write. “…Thus, these results add to a growing body of literature suggesting that bariatric surgery may be a viable treatment option for people with BMI of 30 to 40 for whom medical management is ineffective.”

Figure 2 li vs bs[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]