Fasting Serum Ghrelin Levels Research Articles

The Effect of Biliopancreatic Diversion with Pylorus-Preserving Sleeve Gastrectomy and Duodenal Switch on Fasting Serum Ghrelin, Leptin and Adiponectin Levels: Is there a Hormonal Contribution to the Weight-Reducing Effect of this Procedure?

Ghrelin is a peptide hormone with orexigenic properties, primarily produced by the stomach. Different changes in fasting ghrelin levels have been reported following bariatric surgery. In this study, we investigate the hypothesis that because ghrelin is mainly produced by the fundus of the stomach, biliopancreatic diversion with sleeve gastrectomy with total resection of the gastric fundus and duodenal switch (BPD-DS) will cause substantial decrease in circulating ghrelin levels. Serum fasting ghrelin, leptin and adiponectin concentrations were measured by ELISA in 13 patients with morbid obesity who achieved weight loss by BPD-DS, before the operation and 18 months after. After BPD-DS, BMI decreased significantly, from 59.15+/-15.82 kg/m(2) to 32.91+/-6.46 kg/m(2) (P=0.001). Serum fasting ghrelin level decreased from 1.44+/-0.77 ng/ml to 0.99+/-0.35 ng/ml (P=0.019). Serum leptin level decreased from 1.81+/-0.38 ng/ml to 1.65+/-0.32 ng/ml, (P=0.196), and adiponectin level increased from 37.85+/-11.24 microg/ml to 39.84+/-16.27 microg/ml (P=0.422). BPD-DS is associated with markedly suppressed ghrelin levels, possibly contributing to the longlasting weight-reducing effect of the procedure. Leptin levels decreased and adiponectin increased, as expected, after weight loss. Sleeve gastrectomy with resection of the gastric fundus seems to be the main cause of the postoperative reduction in ghrelin levels.

Menopausal status influences the relationship between serum ghrelin levels and fat mass in healthy women

To examine the relationships of fasting serum ghrelin levels to bone mass index (BMI) and body fat mass, focusing on the effects of menopausal status and changes in fat distribution in women after menopause. An observational study. Fifty-nine pre-menopausal and 31 post-menopausal healthy Japanese women volunteers were enrolled in the present study. Total and regional body fat mass weight was measured by dual energy x-ray absorptiometry. Serum ghrelin was measured. Relationships of serum ghrelin levels to weight, BMI, total body and regional fat mass weight were separately examined in post-menopausal and pre-menopausal women. Serum ghrelin levels were significantly inversely correlated with weight (r = -0.377, p < 0.05, Pearson's correlation test), right arm fat mass (r = -0.408, p < 0.05), left arm fat mass (r = -0.386, p < 0.05), trunk fat mass (r = -0.361, p < 0.05) and total body fat mass (r = -0.383, p < 0.05) in the post-menopausal women but not in pre-menopausal women. Menopausal status may influence the relationship between serum ghrelin levels and fat mass in healthy women.

Correlation of serum ghrelin levels with body mass index and carbohydrate metabolism in patients treated with atypical antipsychotics

The prevalence of diabetes mellitus and metabolic syndrome is higher in patients with schizophrenia than in the normal population. Atypical antipsychotic drugs are used in psychiatry since the beginning of 1990. These drugs differ from the “typical” antipsychotics used previously, as they have less extrapyramidal side effects, and because of this they are tolerated better, but are associated with weight-gain and disturbances in carbohydrate metabolism. Ghrelin is an orexigen hormone partaking in body weight regulation. It is produced in the enteroendocrine P/D1 cells of the gastric mucosa and secreted to the circulation. The aim of our study was to determine ghrelin levels of atypical antipsychotic-treated patients in relationship with their body mass index (BMI) and carbohydrate metabolism. We measured the fasting serum ghrelin levels in 56 patients (male/female: 16/40, age mean ± S.D.: 50.6 ± 5.6 years) treated with atypical antipsychotics (clozapine, olanzapine, risperidon and quetiapine), and in 75 healthy control subjects, age and gender matched (RIA Linco, USA) in relationship with their BMI and their fasting and 75 g OGTT 120 min blood glucose values. The serum ghrelin levels of the patient group were notably higher (1333 ± 659 pg/ml) than in the control group (368 ± 103, p < 0.0001; Mann–Whitney). We found no difference among the four antipsychotics in weight-gain, diabetes prevalence and the serum ghrelin levels. The BMI of the patient group was significantly higher (29.3 ± 7.2 kg/m 2 versus 24.3 ± 3.7 kg/m 2, p < 0.0001; Mann–Whitney); 32% of them had blood glucose abnormality (18/56). There was no difference between the ghrelin levels in diabetic and non-diabetic patients. We found a significant negative linear correlation between the serum ghrelin and BMI ( r = −0.35, p = 0.0078; Spearman), the ghrelin and fasting blood glucose ( r = −0.32, p = 0.015) and OGTT 75 g 120 min blood glucose levels ( r = −0.27, p = 0.036). The orexigen effect of elevated serum ghrelin levels can contribute to the weight-gain and high diabetes prevalence associated with atypical antipsychotic treatment. The link between atypical antipsychotic treatment and elevated serum ghrelin levels is unknown so far, but a dysregulation of the central feedback mechanism can be hypothesised.

Ghrelin levels before and after reduction of overweight due to a low-fat high-carbohydrate diet in obese children and adolescents

There are conflicting results for ghrelin changes in reduction of overweight. Increasing ghrelin levels in weight reduction are considered to be responsible for compensatory mechanisms that make the reduction of overweight unlikely to be sustained. We have analyzed fasting serum ghrelin levels, weighed dietary record and, as biochemical markers of clinically relevant reduction of overweight, leptin, adiponectin and insulin levels and insulin resistance measured by homeostasis model assessment (HOMA) at baseline and after a 1-y outpatient weight reduction program based on a high-carbohydrate and low-fat diet in 37 obese children (median age 10 y). We divided these children into two subgroups according to their degree of weight loss (substantial reduction of overweight: decrease in SDS-BMI > or = 0.5). Furthermore, we analyzed ghrelin levels in 16 normal-weight children. Obese children demonstrated significant (P<0.001) lower ghrelin levels compared to normal-weight children. Daily caloric intake (P = 0.004) and percentage fat content decreased significantly (P<0.001), while percentage carbohydrate content increased significantly (P = 0.003) between baseline and 1-y follow-up in the obese children. The substantial reduction of overweight in 16 children (median SDS-BMI = -0.7) was associated with significant changes in insulin resistance (median decrease of HOMA 27%; P = 0.013), insulin (median decrease 25%, P = 0.036), adiponectin (median increase 15%; P = 0.003), and leptin levels (median decrease 19%; P = 0.023), while there were no significant changes in ghrelin levels (median increase 4%; P = 0.326). In the 21 children without substantial reduction of overweight (median SDS-BMI = -0.3), there were no significant changes in insulin resistance and in insulin, adiponectin, leptin and ghrelin levels. We conclude that in obese children, low-fat high-carbohydrate diet-induced weight loss does not change ghrelin secretion, but significantly decreases leptin levels, increases adiponectin levels and improves insulin resistance determined by significantly decreased insulin resistance indices as well as lowered serum insulin levels.

Short-term effects of gastric bypass surgery on circulating ghrelin levels.

To prospectively evaluate the short-term effects of Roux-en-Y gastric bypass (RYGBP) on ghrelin secretion and its relevance on food intake and body weight changes. Ghrelin response to a standardized test meal was evaluated in eight obese patients (BMI, 43.5 to 59.1 kg/m2) before and 6 weeks after RYGBP. Ghrelin response was compared with that of an age-matched group of six normal weight individuals (BMI, 19.6 to 24.9 kg/m2). Fasting serum ghrelin levels were lower in obese subjects compared with controls (p < 0.05). Meal ingestion significantly suppressed ghrelin concentration in controls (p < 0.05) and obese subjects (p < 0.05), albeit to a lesser degree in the latter group (p < 0.05). Despite a 10.3 +/- 1.5% weight loss, fasting serum ghrelin levels were paradoxically further decreased in obese subjects 6 weeks after RYGBP (p < 0.05). Moreover, at this time-point, food intake did not elicit a significant ghrelin suppression. The changes in ghrelin secretion after RYGBP correlated with changes in insulin sensitivity (p < 0.05) and caloric intake (p < 0.05). This study showed that the adaptive response of ghrelin to body weight loss was already impaired 6 weeks after RYGBP. Our study provides circumstantial evidence for the potential role of ghrelin in the negative energy balance in RYGBP-operated patients.

Circulating ghrelin levels in celiac patients

Objective Ghrelin, the gut–brain peptide, recently identified as the natural endogenous ligand for growth hormone secretagogue receptors, exerts various endocrine and nonendocrine effects, including the control of energy homeostasis and food intake, but its possible relevance in malabsorption syndromes is unknown. Therefore, the aim of this study was to evaluate circulating ghrelin levels in adults with untreated and treated celiac disease (CD) and, for comparison, in healthy subjects. Methods Fasting serum ghrelin levels were measured in 30 consecutive patients with newly diagnosed CD, 13 celiac patients successfully treated with a gluten-free diet (GFD), and 30 healthy controls. Results Ghrelin levels were abnormally high in patients with active CD compared with controls (297 ± 17.6 vs 218 ± 15.2 pmol/L, p < 0.01) and correlated positively with intestinal mucosal lesion severity ( r s = 0.444, p < 0.02). In the successfully GFD-treated patients, ghrelin values were normal compared with controls (233 ± 22.0 vs 218 ± 15.2 pmol/L, ns) and, moreover, correlated negatively with body mass index ( r = −0.632, p = 0.02), unlike in the untreated patient group ( r = −0.263, ns). Conclusion High ghrelin levels characterized our series of adult patients with newly diagnosed CD and correlated significantly with the degree of severity of intestinal mucosal lesions. This is the first evidence of a relationship between ghrelin and inflammatory processes, but the mechanisms involved are still unclear. Furthermore, our findings suggest that an interplay of hormonal, metabolic, and nutritional factors could influence ghrelin secretion under pathophysiological circumstances.

Serum ghrelin levels in response to glucose load in obese subjects post-gastric bypass surgery.

We sought to elucidate further the mechanisms leading to weight loss after gastric bypass (GBP) surgery in morbidly obese individuals. Ghrelin is a gastroenteric appetite-stimulating peptide hormone, fasting levels of which decrease with increasing adiposity and increase with diet-induced weight loss. In addition, ghrelin levels rapidly decline postprandially. We measured serum ghrelin responses to a 75-g oral glucose tolerance test (OGTT) in 6 subjects who had undergone GBP surgery 1.5 +/- 0.7 years before testing and compared these responses with 6 obese subjects about to undergo GBP surgery, 6 obese nonsurgical subjects (matched for BMI to the post-GBP surgical group), and 5 lean subjects. Despite weight loss induced by the GBP surgery, fasting serum ghrelin levels were significantly lower in the post-GBP surgery group than in the lean subject (by 57%) or pre-GBP surgery (by 45%) group. Serum ghrelin levels during the OGTT were significantly lower in postoperative than in lean, obese pre-GBP surgical, or obese nonsurgical subjects. The magnitude of the decline in serum ghrelin levels between 0 and 120 minutes post-OGTT was significantly smaller in postoperative (by 62%), obese pre-GBP surgical (by 80%), or obese nonsurgical (by 69%) subjects in comparison with lean subjects. Serum ghrelin levels in response to OGTT are lower in subjects post-GBP surgery than in either lean or obese subjects. Tonically low serum ghrelin levels may be involved in the mechanisms inducing sustained weight loss after GBP surgery.

Serum ghrelin levels in acromegaly: effects of surgical and long-acting octreotide therapy.

The orexigenic peptide, ghrelin, is regulated by acute and chronic nutritional state. Although exogenously administered ghrelin stimulates pituitary GH secretion, little is known about the role of ghrelin in endogenous GH secretion or how high GH and IGF-I levels in acromegaly could affect ghrelin secretion and vice versa. Therefore, we evaluated fasting and post oral glucose tolerance test serum ghrelin levels in 19 patients with active acromegaly at baseline and after either surgery in 9 of these or administration of long-acting octreotide (Sandostatin LAR) in the other 10 patients. After surgical cure, fasting ghrelin rose from 312 +/- 56 pg/ml to 548 +/- 97 pg/ml (P = 0.013). Fasting serum ghrelin levels were higher in all patients after surgery and ranged between 112% and 349% of presurgery levels. Ghrelin levels fell significantly during long-acting octreotide therapy from 447 +/- 34 pg/ml to 206 +/- 15 pg/ml (P < 0.0001); ghrelin levels on octreotide ranged between 26% and 70% of baseline levels. Serum ghrelin levels were suppressed significantly during the oral glucose tolerance test in both groups. Pretherapy ghrelin levels correlated negatively with serum insulin levels (r = -0.494; P = 0.03) and insulin resistance as estimated by the homeostasis model assessment score (r = -0.573; P = 0.01). In patients without diabetes mellitus, serum insulin levels in the surgical group were 19.7 +/- 5.4 microU/ml before surgery and fell to 9.7 +/- 0.93 microU/ml after surgery (P = 0.05); levels in the octreotide group were 13.9 +/- 2.8 microU/ml before and fell to 11.2 +/- 2.8 microU/ml on octreotide (P = 0.03). Pretherapy ghrelin levels did not correlate with weight or body mass index, but after therapy in the surgery group ghrelin correlated negatively with weight (r = -0.823, P = 0.012) as has been demonstrated by others in healthy subjects. Ghrelin secretion is dysregulated in active acromegaly; lowered serum levels of ghrelin in active acromegaly rise along with the postsurgery normalization of GH and IGF-I and improved insulin resistance. In contrast to surgical therapy, long-acting octreotide therapy persistently suppressed serum ghrelin levels. It remains to be determined whether altered circulating ghrelin concentrations could impact on body composition changes in acromegaly.