Metabolic Effects of Bariatric Surgery

Obesity and its associated comorbidities are an ongoing health care problem worldwide [1]. It is well known that obese patients are at increased risk for the development of diabetes, hypertension, hyperlipidemia, sleep apnea, osteoarthritis, and other degenerative diseases [2]. Bariatric surgery has demonstrated to achieve, on top of significant weight reduction, also long-term control of metabolic comorbidities in morbidly obese patients [3]. In particular, glycemic control of morbidly obese diabetic patients improves markedly after surgery, and bariatric surgery has been recently proposed as a treatment for diabetic, obese class 1 patients in a statement by the International Diabetes Federation [4]. Nonetheless, most of the evidence on the benefits of bariatric surgery in morbidly obese diabetic patients available today is based on retrospective reviews, and even the few prospective trials have some limitations [5]. A recently published, very critical review [6] states that bariatric surgery does not “cure” diabetes. In addition, whether this acute “cure” will continue to be a long-term benefit in reducing cardiovascular disease morbidity and mortality as well as cancer mortality for patients with type 2 diabetes has to be documented in future studies. Therefore, before large-scale application of bariatric surgery to nonbariatric candidates, outside of controlled clinical trials, can be considered or recommended, sufficient long-term data on outcome and complications has to be collected and reported. In this issue, a wide spectrum of topics have been addressed, ranging from preclinical to clinical reports. Particular attention has been focused on long-term reports. Bariatric surgery with a metabolic indication, “metabolic surgery”, is here to stay. It is our duty to ensure that its development is driven by sound evidence and good clinical judgement.