Metabolic and Endocrine Consequences of Bariatric Surgery

Abstract

Obesity is one of the most serious worldwide epidemics of the twenty-first century according to the World Health Organization. Frequently associated with a number of comorbidities, obesity threatens and compromises individual health and quality of life. Bariatric surgery (BS) has been demonstrated to be an effective treatment to achieve not only sustained weight loss but also significant metabolic improvement that goes beyond mere weight loss. The beneficial effects of BS on metabolic traits are so widely recognized that some authors have proposed BS as metabolic surgery that could be prescribed even for moderate obesity. However, most of the BS procedures imply malabsorption and/or gastric acid reduction which lead to nutrient deficiency and, consequently, further complications could be developed in the long term. In fact, BS not only affects metabolic homeostasis but also has pronounced effects on endocrine systems other than those exclusively involved in metabolic function. The somatotropic, corticotropic, and gonadal axes as well as bone health have also been shown to be affected by the various BS procedures. Accordingly, further consequences and complications of BS in the long term in systems other than metabolic system need to be addressed in large cohorts, taking into account each bariatric procedure before making generalized recommendations for BS. In this review, current data regarding these issues are summarized, paying special attention to the somatotropic, corticotropic, gonadal axes, and bone post-operative health.

Obesity and Related Type 2 Diabetes: A Failure of the Autonomic Nervous System Controlling Gastrointestinal Function?

“…It is well known that weight loss and glycemic control are difficult to achieve by obese patients, and if achieved, are difficult to maintain in the long term, even by drastic lifestyle intervention. This is in contrast with bariatric surgery, which is currently the most effective therapeutic approach for obesity (consistent and lasting weight loss) and Type 2 DM (average improvement in HbA1c was 2.1% in operated patients compared to 0.3% in patients undergoing intensive medical care) [73]. Metabolic improvements occur within days or weeks following surgery, even before significant weight loss occurs.…”

“…Metabolic improvements occur within days or weeks following surgery, even before significant weight loss occurs. Therefore, mechanisms are triggered that go beyond simple weight loss and calorie restriction [73].…”

“…In fact, surgical treatment is often not practicable and at risk of complications, although limited [83]. For instance, operated patients have a higher risk of developing nutrient deficiency-related disorders such as anemia, certain types of neuropathies, or osteoporosis [73].…”

Impact of Weight Loss on the Total Antioxidant/Oxidant Potential in Patients with Morbid Obesity—A Longitudinal Study

“…The mainstay of obesity treatment is to increase physical activity and change dietary behaviors. Nevertheless, weight loss is difficult to maintain over a long time [7,8]. It is also insufficient in patients with morbid obesity (body mass index (BMI) > 40 kg/m 2 ).…”

Bone Mineral Density, Parathyroid Hormone, and Vitamin D After Gastric Bypass Surgery: a 10-Year Longitudinal Follow-Up

“…Though obesity constitutes a considerable health threat, these patients have increased bone mineral density compared with persons with normal weight status [8]. Bariatric procedures, in particular those based on malabsorption, lead to a fall in bone mineral density (BMD) [9][10][11][12], an increase in bone resorption and bone remodeling, and changes in bone histomorphometry parameters [10,13,14]. The risk for fracture increases at several skeletal sites after bariatric surgery [15][16][17].…”