Effect of Bariatric Surgery on Metabolic Syndrome in Chinese Patients with Low Body Mass Index: a Propensity Score Matching Study

Background Bariatric surgery (BS) is known to improve the components of metabolic syndrome (MS) in patients with obesity. However, few studies have evaluated the effect of BS on patients with MS at low BMI levels. The study aims to assess the effect of BS on MS in patients with low BMI by comparing BS with medical therapy (MT). Methods A total of 271 patients with MS who underwent BS and MT at a single institution were reviewed in this retrospective cohort study. A 1:1 propensity score matching was performed for the BS and MT groups with BMI<35 kg/m(2). We analyzed the 5 years effect of BS versus MT on the remission of MS, its components, atherosclerotic cardiovascular disease (ASCVD) risk, and medication used. Results Patients in the MT group showed a decrease in the prevalence of MS to 62% at the 1st year and 10% at the 5th year. In the BS group, MS prevalence in patients with BMI<35 kg/m(2) decreased to 30% and 9% at the 1st and 5th year, whereas in patients with BMI >= 35 kg/m(2) was 26% and 7%, respectively. The 10-year ASCVD risk and the lifetime ASCVD were significantly decreased 5 years after BS in patients with BMI< 35 kg/m(2). The number and daily drug dose of hypoglycemic drugs, antihypertensive medications, and lipid-lowering drugs were reduced from baseline in both BS and MT groups. Conclusion Bariatric surgery significantly improves MS remission rates and long-term cardiovascular risk in Chinese patients with metabolic syndrome and a BMI <35 kg/m(2).