The influence of obstructive sleep apnea syndrome on anthropometric parameters at 12 months after laparoscopic sleeve gastrectomy.

The aim of this study was to assess the influence of obstructive sleep apnea syndrome (OSAS) on the change in anthropometric parameters and body composition, in patients undergoing laparoscopic sleeve gastrectomy (LSG). This prospective study included patients undergoing LSG who had pre-operative polysomnography data and were also evaluated at six and 12 months after surgery. All patients included also had whole body composition analysis data before surgery and at six and 12 months after surgery. The results are presented in comparison between patients with and without OSAS. We included 73 patients in the analysis with a mean ± SD age and body mass index (BMI) of 40.3 ± 10.9 years and 45.4 ± 6.3 kg/m2, respectively. As compared to the baseline levels, at 6 months there was a significant decrease in BMI, weight, waist circumference, serum glucose and HbA1c. At 12 months there was no further decrease as compared to the 6 months levels, irrespective of OSAS status. We observed a significant decrease at 6 months in percentage of fat, in both types of patients. However, as compared to the 6 months levels, at 12 months the percent fat had a significant decrease only in patients without OSAS (- 4.6%, 95% CI - 7.6 to - 1.7%) and not in those with OSAS (- 2.2%, 95% CI - 4.5 to 0.2%). In our study, patients with OSAS showed a similar decrease in different anthropometric parameters as those without OSAS after LSG. However, at 12 months of follow-up there was a significant decrease in the percent fat only in patients without OSAS.

Ghrelin-producing cells distribution in the stomach and the relation with Helicobacter pylori in obese patients.

OBJECTIVE: Ghrelin is believed to influence weight evolution after bariatric surgery. Helicobacter pylori (H. pylori) infection may influence ghrelin plasma levels by affecting the ghrelin-producing cells (GPC) in the stomach. The purpose of the study was to characterize the GPC distribution in the stomach in overweight patients and the influence of H. pylori infection on them. PATIENTS, MATERIALS AND METHODS: The study group included 21 obese patients undergoing bariatric surgery with ghrelin levels and anti-H. pylori antibodies previously measured, and upper gastrointestinal endoscopy with histological evaluation of H. pylori infection performed. Immunohistochemical expression of ghrelin was quantified in gastric resection specimens. RESULTS: The results showed a higher number of GPC in the obese women than in men (p>0.05). The highest number of GPC was detected in the gastric body, followed by the fundus and antral region (p<0.001). GPC number correlated inversely with anthropometric parameters: weight (p=0.011), body mass index (BMI) (p=0.017), waist circumference (WC) (p=0.066) was lower in patients with H. pylori infection (p>0.05) or gastritis (p>0.05), the number decreasing with the increase in depth of gastritis lesion (p>0.05). CONCLUSIONS: The present study fulfills the characterization of GPC in obese patients, showing a higher number in women than in men, their predominant location in the gastric body, and their relationship with the anthropometric parameters (weight, BMI, WC), H. pylori infection and gastritis lesions. These results open broad perspectives for a deeper understanding of the ghrelin involvement in the obesity pathogenic mechanism, associated or not with other gastric conditions.

Effects of ghrelin in energy balance and body weight homeostasis.

Ghrelin is a gut peptide composed of 28 amino acids mostly secreted in the gastric fundus mucosa. It was isolated and described in 1999 by Kojima et al. and only three years later its specific receptor, GHSR1a, was also identified. Ghrelin, the endogenous ligand for the GH secretagogue receptor, is the only peripheral orexigenic hormone that activates the receptors to be found especially in the appetite center (hypothalamus and pituitary gland). Ghrelin is present in human plasma in two forms: an inactive form known as deacylated ghrelin, and an active form called acylated ghrelin synthesized under the action of ghrelin O-acyltransferase enzyme (GOAT). The literature even mentions an extremely complex ghrelin/GOAT/GHSR system involved in the regulation of human energy, metabolism and adaptation of energy homeostasis to environmental changes. In humans, there is a preprandial rise and a postprandial fall in plasma ghrelin levels, which strongly suggest that the peptide plays a physiological role in meal initiation and may be employed in determining the amount and quality of ingested food. Besides the stimulation of food intake, ghrelin determines a decrease in energy expenditure and promotes the storage of fatty acids in adipocytes. Thus, in the human body ghrelin induces a positive energy balance, an increased adiposity gain, as well as an increase in caloric storage, seen as an adaptive mechanism to caloric restriction conditions. In the current world context, when we are witnessing an increasing availability of food and a reduction of energy expenditure to a minimum level, these mechanisms have become pathogenic. As a consequence, the hypothesis that ghrelin is involved in the current obesity epidemic has been embraced by many scholars and researchers.

The role of histological evaluation of Helicobacter pylori infection in obese patients referred to laparoscopic sleeve gastrectomy.

Helicobacter pylori (H. pylori) is the etiological factor for gastritis in more than half of the worldwide population. H. pylori infection increases the risk for gastric pathology, but could also have consequences on cardio-metabolic status. Obesity has as epidemic growth, and the only efficient long-term treatment for morbidly obese patients is currently surgery. Although of vital importance, the preoperative assessment is not standardized, including the aspects related to H. pylori infection. The aim of this prospective study was to evaluate the prevalence of H. pylori (Hp) infection in a group of patients referred to bariatric surgery and the agreement of two commonly used methods for its diagnosis. We included 70 asymptomatic obese patients consecutively for 14 months, who were evaluated by serology (anti-Hp IgG antibodies) and by histology (gastroscopy with gastric mucosa biopsy). If diagnosed, H. pylori infection was standard treated and afterwards, all patients underwent laparoscopic sleeve gastrectomy; the resected stomach was morphologically evaluated. 58.6% of patients were H. pylori positive on serology and 51.4% were H. pylori positive on histology, agreement coefficient factor kappa between the two methods being 0.686, p<0.001. The serological diagnosis had a sensibility of 90.3% and a specificity of 77.8%. The prevalence of H. pylori infection in the resected stomach was 11.4%, and was associated with more severe degrees of chronic gastritis. In conclusion, as gastroscopy should anyhow be performed in all patients referred to surgery, our data favor the histological evaluation in all patients and the eradication treatment according to its results.