Serum leptin and weight loss in severely obese patients undergoing biliopancreatic diversion

Change in Adipokines and Gastrointestinal Hormones After Bariatric Surgery: a Meta-analysis

PURPOSE

The study aimed to perform a meta-analysis about the change in adipokines and gastrointestinal hormones after bariatric surgery in patients with obesity.

MATERIALS AND METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE, and PubMed for related articles and used Review Manager 5.4 for data aggregation. Sensitivity and subgroup analysis were also conducted when feasible.

RESULTS

As a result, 95 articles involving 6232 patients were included in the meta-analysis. After bariatric surgery, the levels of leptin, ghrelin, C-reactive protein (CRP), interleukin-6 (IL-6), high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis, factor-α (TNF-α), and interleukin-1β (IL-1β) reduced, while adiponectin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) levels increased significantly. Subgroup analysis indicated that there was a more significant reduction in leptin level with a longer follow-up time. OAGB had a greater effect on increasing adiponectin level compared with other procedures. SG procedure would bring about reduced ghrelin, while BPD resulted in increased ghrelin. Meta-regression analysis found that publication year, study design, number of patients, preoperative age, preoperative BMI, and quality assessment score were not significantly related to change in leptin, adiponectin, and ghrelin levels.

CONCLUSION

Bariatric surgery was associated with a significant decrease in leptin, ghrelin, CRP, IL-6, Hs-CRP, TNF-α, and IL-1β, as well as increase in adiponectin, GLP-1, and PYY levels.

Changes in Serum Ghrelin Concentration following Biliopancreatic Diversion for Obesity

OBJECTIVE

Ghrelin is a recently discovered hormone that is produced mainly by the stomach and that increases food intake in rodents and humans. It has been postulated that the weight loss after gastric bypass surgery for obesity might be related to changes in serum ghrelin concentration.

RESEARCH METHODS AND PROCEDURES

Serum leptin and ghrelin concentrations were measured in a group of obese patients before biliopancreatic diversion (BPD) and 2 and 12 months postoperatively. Insulin sensitivity was determined from serum glucose and insulin levels according to the homeostatic model of assessment for insulin resistance (HOMA IR).

RESULTS

A sharp drop was observed in body weight, in BMI values, in HOMA IR data, and in serum leptin concentration at 2 and 12 months after BPD, whereas a significant increase of serum ghrelin level was observed at 12 months, when food intake had returned to preoperative levels. A negative correlation between the postoperative changes of serum ghrelin concentration and those of HOMA IR values was observed at 2 and 12 months after BPD.

DISCUSSION

No evidence upholding a relationship between serum ghrelin concentration and food intake after BPD was seen; the postoperative changes likely reflected the achievement of a new state of energy balance. The negative relationship observed between post-BPD changes in HOMA IR values and changes in serum ghrelin concentration supported the role of insulin in the modulation of ghrelin production.

Temporal changes in glucose and insulin homeostasis after biliopancreatic diversion and laparoscopic adjustable gastric banding

BACKGROUND

Obesity surgery is associated with improvement in type 2 diabetes mellitus. Our aim was to examine the effects of biliopancreatic diversion (BPD) and laparoscopic adjustable gastric banding (LAGB) on the body mass index, fasting insulin level, glucose level, and insulin resistance in morbidly obese subjects with type 2 diabetes mellitus. The setting was the Department of Surgery, Morriston Hospital (Swansea, Wales, United Kingdom).

METHODS

A total of 13 morbidly obese patients (7 BPD, 6 LAGB) underwent serial measurements of fasting glucose and insulin at baseline, immediately after surgery (days 1-7), and 1, 6, and 12 months postoperatively. The homeostasis model of assessment-insulin resistance was calculated.

RESULTS

In the BPD group, the glucose levels had normalized by day 3 (5.6 ± 1 mmol/L) and the difference was statistically significant at 6 and 12 months postoperatively (5 ± .7 and 4.4 ± .5 mmol/L, respectively). The insulin levels had improved from day 1, and the difference was statistically significant at days 2, 5, 6, and 7 (19 ± 9, 14.2 ± 7, 15.2 ± 8, and 17.4 ± 8 mU/L, respectively). All diabetes medications were stopped on the fourth postoperative day. In the LAGB group, no statistically significant changes were seen in the glucose levels. Statistically significant changes in insulin were seen on days 1 and 2 (19 ± 13 and 13 ± 6.5 mU/L, respectively). The homeostatic model of assessment-insulin resistance had improved in both groups (BPD, 1.6 ± 1.2, P < .01; and LAGB, 4.3 ± 1.4, P < .05).

CONCLUSION

BPD causes immediate remission of type 2 diabetes mellitus. Leptin might play an important role in the early improvement of insulin resistance in fasting states after BPD. In the LAGB group, glucose homeostasis improved, but the patients still required diabetes medications, although the dosages were reduced.

Genotype-specific weight loss treatment advice: how close are we?

Obesity, whose prevalence is continually rising, is one of the world’s greatest health care burdens. This multifactorial condition is associated with many obesity-related conditions, such as type 2 diabetes, dyslipidemia, and cardiovascular disease. Weight loss is a significant challenge facing those wishing to reduce their disease risk. Of course, like obesity itself, weight loss is a complex phenomenon dependent on many environmental and genetic influences, and thus individual responses to weight loss interventions are incredibly variable. Currently, there are 3 major interventions used to reduce weight: diet, exercise, and pharmacotherapy. The findings from studies examining gene–diet (nutrigenetic), gene–exercise (actigenetic), and gene–pharmaceutical (pharmacogenetic) interactions, although not clinically applicable at this time, are gaining awareness. This review article summarizes the current evidence to support the contribution of DNA sequence variation in genes related to energy balance (expenditure and intake) in the response to weight loss intervention. There is no doubt that replication using more rigorous study designs that include the study of interactions between multiple genes and interventions is required to move towards the development of genotype-specific weight loss treatment strategies.

Effect of Biliopancreatic Diversion on Hypertension in Severely Obese Patients

Hypertension is a medical disorder frequently associated with severe obesity, and the effect of weight loss on the reduction of blood pressure has been well established. In this study, the relationships between the weight loss surgically obtained by biliopancreatic diversion and blood pressure were investigated in a population of severely obese patients with preoperative hypertension. At 1 year following the operation, blood pressure was normalized in more than half of patients; in a further 10% of cases the hypertensive status resolved within the 3-year follow-up period. The resolution of hypertension was independently associated with age and body weight and was unrelated to sex, the amount of weight loss, or body fat distribution. In severely obese patients with hypertension undergoing bariatric surgery, biliopancreatic diversion is advisable since it achieves and supports the maintenance of body weight close to the ideal value.

BMI is the main determinant of the circulating leptin in women after vertical banded gastroplasty

OBJECTIVE

To assess the main determinant of serum leptin concentration changes in morbidly obese patients treated by banded vertical gastroplasty.

RESEARCH METHODS AND PROCEDURES

Serum leptin and insulin concentrations, insulin resistance, BMI, body weight, and body fat mass in 18 obese women and 8 obese men treated by vertical banded gastroplasty were studied. Lean women and men subjects were used as controls.

RESULTS

Before surgery, serum leptin and insulin concentrations and insulin resistance index were significantly higher in morbidly obese patients than in control subjects. BMI, body fat mass, and serum triacylglycerol concentrations were also significantly higher in obese than in lean subjects. All of these parameters gradually decreased during 50 weeks after surgery. Univariate regression analysis displayed significant correlations between the following: serum leptin concentration and BMI (and body fat mass), serum leptin concentration and serum insulin concentration, and serum leptin concentration and insulin resistance index. Multivariate regression analysis indicated that only BMI was independently correlated with the decrease in serum leptin concentration.

DISCUSSION

Obtained data suggest the following: 1) vertical banded gastroplasty causes reduction of body weight, serum leptin and insulin concentration, insulin resistance, and serum triacylglycerol concentration; and 2) BMI is the main determinant of the circulating leptin concentration in morbidly obese women after anti-obesity surgery.

Recovery of insulin sensitivity in obese patients at short term after biliopancreatic diversion

OBJECTIVE

To gain insight into the specific mechanisms by which biliopancreatic diversion (BPD) can improve insulin action.

MATERIALS AND METHODS

Nondiabetic severely obese patients (n=20) undergoing BPD were included. Waist-to-hip ratio and serum concentration of glucose, insulin, and leptin were determined before, at 4-day, and at 2 months after the operation. Insulin sensitivity was calculated according to the homeostatic model assessment (HOMA IR).

RESULTS

A marked increase of insulin sensitivity was observed by the fourth day after the operation; at the second postoperative month, when body weight was still in the obese range and the food intake was substantially similar to the preoperative one, a further improvement of insulin action towards normality was found. Moreover, before BPD HOMA IR data were independently correlated both to BMI and waist-to-hip ratio values, whereas at 2 months after the operation data were in positive correlation only with the BMI.

DISCUSSION

In obese patients, BPD seems to achieve recovery of insulin sensitivity by specific mechanisms independent of weight loss: the main causes of this sharp improvement might be both the intramyocellular fat depletion and the interruption of enteroinsular axis.

Serum leptin concentration in obese patients with binge eating disorder

BACKGROUND

In steady-state conditions serum leptin concentration is directly related to body fat stores, but is also affected by changes in energy balance. This cross-sectional study investigated the serum leptin concentrations of severely obese patients with binge eating disorder (BED), in whom body fat was greater than normal and, because of eating pattern, rapid and repeated changes in energy balances took place.

METHODS

A group of BED obese patients was compared to a group of obese patients with a regular eating pattern with the same body weight, body composition and resting energy expenditure. Serum leptin was measured and the eating attitudes were evaluated by Eating Inventory and Eating Disorder Inventory.

RESULTS

In these patients serum leptin concentrations were only weakly correlated to body mass. Furthermore, in BED obese patients serum leptin concentration was higher than in their non binging counterparts.

CONCLUSIONS

In obese patients both body fat size and eating behavior influence serum leptin concentration, but BED patients binge eating is not triggered by a low leptin value.

Lowering of circulating free-fatty acids levels and reduced expression of leptin in white adipose tissue in postobesity status

BACKGROUND

Our aim was to investigate the regulation of the gene expression of leptin in subcutaneous adipose tissue biopsies in morbid obesity before and after biliopancreatic diversion (BPD).

METHODS

Longitudinal study in morbidly obese subjects investigated twice: before and 6 months after BPD. Fourteen morbidly obese women, 37+/-13 years old and with a body mass index of 51.6+/-8.2 kg/m2, were studied before and 6 months after BPD (40.6+/-8.0 kg/m2). Using reverse transcriptase polymerase chain reaction analysis, the mRNA expression of leptin was investigated in adipose tissue. Plasma leptin was measured by radioimmunoassay; plasma insulin was measured by microparticle enzyme immunoassay. Free fatty acids (FFA) were measured using a colorimetric kit.

RESULTS

A significant decrease in leptin mRNA level was observed in comparison with pretreatment in BPD patients (59+/-34 vs 143+/-85 arbitrary units, P<0.01). A strict relationship between adipose tissue leptin mRNA and plasma leptin either before (R2=0.80, P<0.0001) or after BPD (R2=0.86, P<0.0001) and between plasma FFA concentration and insulin either before (R2=0.65, P<0.001) or after BPD (R2=0.92, P<0.0001) was observed. Finally, a significant correlation was found between changes in FFA and insulin (R2=0.64, P<0.001), insulin and leptin (R2=0.88, P<0.0001), and insulin and leptin mRNA (R2=0.83, P<0.0001).

CONCLUSION

These data demonstrate a high correlation between leptin mRNA expression in adipose tissue and plasma leptin in postobese subjects after BPD. The significant relationship between both leptin mRNA and plasma leptin with insulin suggests that circulating insulin might regulate leptin expression. It might be hypothesized that plasma FFA concentration can act on the insulin secretion and subsequently on the leptin secretory pathway.

Serum leptin concentrations in children with Prader-Willi syndrome and non-syndromal obesity

There is limited information on the underlying physiological mechanisms promoting obesity in patients with Prader-Willi syndrome (PWS). The aim of this study was to investigate whether body fat regulation in children with PWS is similar to that in children with non-syndromal obesity and non-obese children. We studied three groups: 1) 72 non-obese children and adolescents; 2) 68 children with non-syndromal obesity; and 3) 11 patients with PWS. Height and weight were measured and body mass index (BMI) and BMI SDS were calculated. Fasting serum leptin concentrations were determined. Median leptin serum concentrations were similar in PWS patients and children with non-syndromal obesity. Median leptin serum concentrations were higher in these two groups than in the non-obese group. Log leptin serum concentrations and BMI SDS showed significant correlations in the three groups of patients; correlation coefficients were 0.525, 0.285 and 0.854, respectively. In conclusion, median leptin serum concentrations are similar in PWS patients and children with non-syndromal obesity. The relationship between log serum leptin concentrations and BMI SDS was different in the three groups of patients studied.