Effect of bariatric surgery versus medical therapy on long-term cardiovascular risk in low BMI Chinese patients with type 2 diabetes: a propensity score-matched analysis

Abstract

Background: Reducing the risk of death due to cardiovascular disease (CVD) is an important direction for diabetes prevention and treatment. The Chinese population with type 2 diabetes (T2D) has a high risk of developing CVD at relatively low body mass index (BMI) levels. Currently, no studies have evaluated the effect of bariatric surgery versus medical therapy on long-term CVD risk in patients with T2D and low BMI.

Objectives: To compare bariatric surgery versus medical therapy for long-term CVD risk in Chinese patients with T2D and low BMI by using the China Prediction for ASCVD Risk equations and the United Kingdom Prospective Diabetes Study risk engine.

Setting: University hospital, China.

Methods: Medical records of patients with T2D with a BMI <35 kg/m² undergoing bariatric surgery or medical therapy from May 2010 to December 2018 were reviewed. A 1:1 propensity score matching was performed by using 7 preoperative characteristics. Variables for calculating CVD risk scores over the 5-year follow-up were assessed.

Results: A total of 684 patients with T2D underwent bariatric surgery (n = 75) or medical therapy (n = 609), and 52 pairs of matched subjects were selected from both groups after propensity score matching. The 10-year and lifetime atherosclerotic CVD risk by using the China Prediction for ASCVD Risk equation at 5 years follow-up period in the bariatric surgery group improved significantly compared with the medical therapy group. In the fifth year of follow-up, the 10-year risk of coronary heart disease, fatal coronary heart disease, stroke, and fatal stroke by using the United Kingdom Prospective Diabetes Study risk engine were much lower in the bariatric surgery group than in the medical therapy group (10.37 ± 5.64% versus 27.25 ± 7.28%, P = .004; 6.3 ± 4.5% versus 22.3 ± 7.35%, P = .002; 4.97 ± 3.73% versus 15.05 ± 3.63%, P = .001; .59 ± .45% versus 1.52 ± .14%, P < .001. respectively). The use of glucose-lowering medications, including insulin, was reduced from baseline in both groups, and patients in the bariatric surgery group required significantly fewer of these medications than those in the medical therapy group.

Conclusion: Bariatric surgery in patients with T2D and low BMI conferred a lower calculated risk of CVD compared with medical therapy over 5 years of follow-up.

Keywords: Bariatric surgery; Cardiovascular disease; China-PAR equation; Medical therapy; Type 2 diabetes; UKPDS risk score.