Gastric bypass surgery vs intensive lifestyle and medical intervention for type 2 diabetes: the CROSSROADS randomised controlled trial

Abstract

Aims/hypothesis: Mounting evidence indicates that Roux-en-Y gastric bypass (RYGB) ameliorates type 2 diabetes, but randomised trials comparing surgical vs nonsurgical care are needed. With a parallel-group randomised controlled trial (RCT), we compared RYGB vs an intensive lifestyle and medical intervention (ILMI) for type 2 diabetes, including among patients with a BMI <35 kg/m(2).

Methods: By use of a shared decision-making recruitment strategy targeting the entire at-risk population within an integrated community healthcare system, we screened 1,808 adults meeting inclusion criteria (age 25-64, with type 2 diabetes and a BMI 30-45 kg/m(2)). Of these, 43 were allocated via concealed, computer-generated random assignment in a 1:1 ratio to RYGB or ILMI. The latter involved ≥45 min of aerobic exercise 5 days per week, a dietitian-directed weight- and glucose-lowering diet, and optimal diabetes medical treatment for 1 year. Although treatment allocation could not be blinded, outcomes were determined by a blinded adjudicator. The primary outcome was diabetes remission at 1 year (HbA1c <6.0% [<42.1 mmol/mol], off all diabetes medicines).

Results: Twenty-three volunteers were assigned to RYGB and 20 to ILMI. Of these, 11 withdrew before receiving any intervention. Hence 15 in the RYGB group and 17 in the IMLI group were analysed throughout 1 year. The groups were equivalent regarding all baseline characteristics, except that the RYGB cohort had a longer diabetes duration (11.4 ± 4.8 vs 6.8 ± 5.2 years, p = 0.009). Weight loss at 1 year was 25.8 ± 14.5% vs 6.4 ± 5.8% after RYGB vs ILMI, respectively (p < 0.001). The ILMI exercise programme yielded a 22 ± 11% increase in [Formula: see text] (p<0.0001), whereas [Formula: see text] after RYGB was unchanged. Diabetes remission at 1 year was 60.0% with RYGB vs 5.9% with ILMI (p = 0.002). The HbA1c decline over 1 year was only modestly more after RYGB than ILMI: from 7.7 ± 1.0% (60.7 mmol/mol) to 6.4 ± 1.6% (46.4 mmol/mol) vs 7.3 ± 0.9% (56.3 mmol/mol) to 6.9 ± 1.3% (51.9 mmol/mol), respectively (p = 0.04); however, this drop occurred with significantly fewer or no diabetes medications after RYGB. No life-threatening complications occurred.

Conclusions/interpretation: Compared with the most rigorous ILMI yet tested against surgery in a randomised trial, RYGB yielded greater type 2 diabetes remission in mild-to-moderately obese patients recruited from a well-informed, population-based sample.

Trial registration: ClinicalTrials.gov NCT01295229.

Keywords: Bariatric surgery; Diabetes; Intensive lifestyle; Metabolic surgery; Randomised controlled trial.

Conflict of interest statement

Duality of interest

DA receives research funding, has received salary support and received free access to the SDM aids used in this study, as a medical editor for the not-for-profit (501[3]c) Informed Medical Decisions Foundation (www.informedmedicaldecisions.org), which develops content for patient education programmes, including the bariatric surgery programme that was used by participants of this study. The Foundation had an arrangement with a for-profit company, Health Dialog, to co-produce and market these programmes to healthcare organisations. All other authors declare that there is no duality of interest associated with their contribution to this manuscript. The authors’ spouses, partners, or children have no financial relationships that may be relevant to the submitted work. The authors have no nonfinancial interests that may be relevant to the submitted work.

Figures

Fig. 1

Participant identification, education and recruitment flow diagram

Fig. 2

Change in HbA1c over time by treatment group (n=17 ILMI; n=15 RYGB); dashed line and white squares, ILMI group; solid line and black circles, RYGB group. To convert values for HbA1c in per cent into mmol/mol, subtract 2.15 and multiply by 10.929

Fig. 3

Changes in secondary outcomes over time by treatment group (n=17 ILMI; n=15 RYGB); black bars, ILMI baseline; light grey bars, ILMI 1 year; dark grey bars, RYGB baseline; white bars, RYGB 1 year. Fat and lean mass determined by DEXA. *p<0.05 for within-group comparison of baseline vs 1 year. †p<0.05 for between-group comparison of change between baseline and 1 year. ‡p=0.05 for between-group comparison of change. §p=0.08 for between-group comparison of change