Bariatric surgery reduces risk of microvascular complications in diabetes

Compared with usual care, bariatric surgery in adults with type 2 diabetes mellitus (T2DM) is associated with a lower overall incidence of microvascular disease (including lower risk of retinopathy, neuropathy, and nephropathy), according to a new study published in the journal Annals of Internal Medicine.

Bariatric surgery improves glycemic control in patients with type 2 diabetes mellitus (T2DM), but less is known about microvascular outcomes. Rebecca O'Brien, The Permanente Medical Group, Kaiser Permanente Northern California, Oakland, California, and colleagues conducted the study to investigate the relationship between bariatric surgery and incident microvascular complications of T2DM.

The researchers conducted the retrospective matched cohort study from 2005 to 2011 with follow-up through September 2015. Patients aged 19 to 79 years with T2DM who had bariatric surgery (n = 4024) were matched on age, sex, body mass index, hemoglobin A_1c level, insulin use, diabetes duration, and intensity of health care use up to 3 nonsurgical participants (n = 11 059). Median follow-up was 4.3 years for both surgical and nonsurgical patients.

“Our results add to a growing body of evidence suggesting that bariatric surgery not only improves glucose, blood pressure and lipid control but is likely to reduce macrovascular and microvascular complications, as well as improve survival, in patients with severe obesity and [type 2 diabetes],” wrote the authors.

• Bariatric surgery was associated with significantly lower risk for incident microvascular disease at 5 years (16.9% for surgical vs. 34.7% for nonsurgical patients; adjusted hazard ratio [HR], 0.41 [95% CI, 0.34 to 0.48]).


• Bariatric surgery was associated with lower cumulative incidence at 5 years of diabetic neuropathy (7.2% for surgical vs. 21.4% for nonsurgical patients; HR, 0.37 [CI, 0.30 to 0.47]), nephropathy (4.9% for surgical vs. 10.0% for nonsurgical patients; HR, 0.41 [CI, 0.29 to 0.58]), and retinopathy (7.2% for surgical vs. 11.2% for nonsurgical patients; HR, 0.55 [CI, 0.42 to 0.73]).

"The findings from this study should help patients and providers to better understand the potential tradeoffs of bariatric surgery as the treatment of [type 2 diabetes] and help them to make more informed decisions about care,” concluded the authors.