Weight loss after bariatric surgery is strongly associated with an initial remission of type 2 diabetes (T2D), but the rate of remission does not increase substantially above a threshold of 20% total weight loss (TWL), according to a study in Diabetes Care.
Investigators assessed the relationship between surgical weight loss and initial T2D remission in a diverse population of patients who had either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery. Data were obtained from a health care system of 4.2 million patients living in southern California.
Remission of T2D was the primary outcome. The primary exposure of interest was the percent of TWL from surgery to the first instance of T2D remission or to censorship if no remission was observed. (Censoring occurred upon loss of membership, death, last weight measurement, or the end of the study period).
The analysis included 5928 patients with T2D (mean age, 49.8±10.3 years; 73% female; mean body mass index, 43.8±6.92 kg/m2). Fifty-seven percent of the patients had RYGB surgery. The patients were followed for an average of 5.9 years, during which 71% had an initial T2D remission (72% for RYGB and 70% for SG). The average time to remission was 1.0 years (0.98 years for RYGB and 1.01 years for SG), and the 5-year retention rate was 82.9%.
Compared with patients who had TWL of 0% to ≤5%, those who lost successively more weight were more likely to remit, starting with those who had >10% to ≤15% TWL and continuing through those who had >20% to ≤25% TWL. Patients with TWL of >10% to ≤15% were 1.97 times more likely to remit (hazard ratio [HR] 1.97; CI, 1.47-2.64); those with >15% to ≤20% TWL were 2.33 times more likely to remit (HR 2.33; CI, 1.74-3.11), and those with TWL >20% to ≤25% were 2.81 times more likely to remit (HR 2.81; CI, 2.11-3.75).
Patients with >25% TWL had a likelihood of initial T2D remission comparable to those who had 20% to 25% TWL. The overall relationship between the percent of TWL and initial T2D remission was different for non-Hispanic Black patients compared with White patients, but not between any other race or ethnicity. Regardless of race or ethnicity, all patients had the same likelihood of initial T2D remission if they had at least 0 to ≤5% TWL.
Patients with insulin use at the time of surgery and >20% TWL were 2.18 times more likely to have initial T2D remission vs those who were not taking insulin but only had 0% to ≤5% TWL (HR 2.18; CI,1.64-2.88). An increase in T2D remission likelihood with insulin use before surgery was only observed in patients with >20% TWL.
Patients with diabetes and their initial remission were determined using electronic data sources only, a factor that researchers said was a limitation of their study, as well as an analysis which focused on T2D remission and not durable T2D remission. Additionally, the researchers said, the results with stratification by surgical operation should be interpreted with caution because of selection by patients and physicians between these 2 operations.
“Our findings can be used to help providers and patients discuss realistic expectations for weight loss following bariatric surgery and how this will affect their T2D remission,” the investigators commented.
Disclosure: Some of the study authors declared affiliations with pharmaceutical and/or health care consulting companies. Please see the original reference for a full list of authors’ disclosures.
Barthold D, Brouwer E, Barton LJ, et al. Minimum threshold of bariatric surgical weight loss for initial diabetes remission. Diabetes Care. Published online September 13, 2021. doi:10.2337/dc21-0714