Diabetes Patients Who Had Metabolic Surgery Still Have HbA1c 1.1 Points Lower After 12 Years

Long-term follow-up results published in JAMA show that when people with type 2 diabetes and obesity have metabolic and bariatric surgery, the blood glucose control benefit lasts more than 10 years, compared with medication and lifestyle management alone. This is the pooled ARMMS-T2D analysis by researchers at the University of Pittsburgh and several other institutions in the United States.

Four Randomised Trials Combined, Up to 12 Years of Follow-Up

The researchers pooled the participants of four single-centre randomised controlled trials in the United States and continued observational follow-up. Of 305 eligible people, 262 took part, with an average age of 49.9 years and an average body mass index (BMI) of 36.4. The surgery group had one of Roux-en-Y gastric bypass, sleeve gastrectomy or adjustable gastric banding. Median follow-up was 11 years.

At 7 years, HbA1c had fallen by 0.2 percentage points in the medication and lifestyle group and by 1.6 percentage points in the surgery group, a 1.4-point difference between the groups, and a 1.1-point difference remained at 12 years. Diabetes remission rates were 6.2% vs. 18.2% at 7 years and 0% vs. 12.7% at 12 years. The surgery group also used fewer diabetes medicines. Death and major cardiovascular events did not differ between the two groups, but anaemia, fractures and gastrointestinal adverse events were more common in the surgery group.

Stronger Long-Term Evidence, but a Small Sample

The study is significant in showing, with randomisation-based data, that the blood glucose benefit of metabolic surgery largely remains over time. However, the sample numbers only in the hundreds, and 25% of the medication and lifestyle group had surgery during follow-up, which may have diluted the difference between groups. The trials were designed before GLP-1-class drugs came into wide use, so the results are also hard to read as a comparison with those drugs.