Additional effect of visceral fat resection in an obese rat model of gastric banding

Effects of sleeve gastrectomy on lipid metabolism in an obese diabetic rat model

BACKGROUND

Laparoscopic sleeve gastrectomy (SG) is a popular bariatric procedure for treating morbid obesity. This study aimed to investigate the relation between SG and lipid metabolism in an obese diabetic rat model.

METHODS

Forty-five male Zucker diabetic fatty (ZDF) rats were divided into three groups: sham-operated (SO) control, gastric banding (GB), and SG. Six weeks after surgery, metabolic parameters, including plasma adiponectin level, small bowel transit, mRNA expression of peroxisome proliferator-activated receptor (PPAR)-α and PPARγ in the liver, skeletal muscle and white adipose tissue, and that of adiponectin in white adipose tissue, and triglyceride (TG) contents in the liver and skeletal muscle were measured.

RESULTS

Metabolic parameters in the GB and SG groups were significantly improved compared with those in the SO group. However, plasma total cholesterol (TC) and free fatty acid (FFA) concentrations were significantly lower while the plasma adiponectin level was significantly higher in the SG group than in the GB and SO groups. In addition, small bowel transit time was significantly shorter in the SG group than in the other two groups. Furthermore, in the SG group, mRNA expression of PPARα in the liver and skeletal muscle and that of adiponection and PPARγ in white adipose tissue were significantly higher, while TG in the liver and skeletal muscle were significantly lower, compared with those in the other two groups.

CONCLUSIONS

These results suggest that SG improves lipid metabolism compared with GB, although there were no significant differences in the effect on weight loss between the two procedures.

A comparative study of gastric banding and sleeve gastrectomy in an obese diabetic rat model

BACKGROUND

Laparoscopic sleeve gastrectomy (SG) is now a typical restrictive bariatric procedure. The aim of this study was to evaluate the efficacy of SG in comparison with gastric banding (GB) in an obese diabetic rat model.

METHODS

Forty-five male Zucker diabetic fatty rats were divided into three groups: sham-operated (SO) control, GB, and SG. The rats were followed for 6 weeks after surgery, and their body weight change, cumulative food intake, metabolic parameters, plasma levels of ghrelin, glucagon-like peptide-1 and adiponectin, oral glucose tolerance test (OGTT), insulin tolerance test (ITT), and gastric emptying rate were measured.

RESULTS

The GB and SG groups showed significant decreases in weight, cumulative intake, and metabolic parameters and significant improvement of OGTT and ITT results compared with the SO group. There were no significant differences in weight and cumulative food intake between the groups. However, the SG group showed significantly higher gastric emptying rate and plasma level of adiponectin and lower plasma levels of free fatty acid, total cholesterol, and ghrelin compared with the GB group. Furthermore, the SG group showed improvement of OGTT and ITT results in comparison with the GB group.

CONCLUSIONS

In obese diabetic rats, SG may improve glucose and lipid metabolism compared with GB, although there was no significant difference in the effect on body weight loss between the two procedures. The hormonal and digestive changes induced by SG may have relevance to the effects on metabolism.

Effects of visceral fat resection and gastric banding in an obese diabetic rat model

BACKGROUND

Although the function of visceral fat has gradually become clear, the effects of its resection on insulin resistance and glucose metabolism are still unknown. This study aimed to clarify the effects of visceral fat resection and gastric banding in an obese diabetic rat model.

METHODS

Forty male Zucker diabetic fatty rats were divided into 4 groups: sham operation, visceral fat resection, gastric banding, and gastric banding with visceral fat resection. The rats were followed for 8 weeks after operation, and the change in body weight, amount of food intake, metabolic parameters, insulin tolerance, oral glucose tolerance, and adipocytokines were examined.

RESULTS

Compared with the sham operation and visceral fat resection groups, the gastric banding and gastric banding + visceral fat resection groups showed significant decreases in weight gain and cumulative food intake, as well as improvement in secretion of adipocytokines and in insulin resistance. Although no differences were found between the sham operation and visceral fat resection groups in weight gain and food intake, high-molecular-weight adiponectin, tumor necrosis factor-α levels, and insulin resistance were improved in the visceral fat resection group compared with the sham operation group. The gastric banding + visceral fat resection group had greater serum levels of high-molecular-weight adiponectin than did the gastric banding group, but no difference was found between the gastric banding and gastric banding + visceral fat resection groups in insulin resistance and glucose metabolism.

CONCLUSION

In diabetic fatty rats, the surgical removal of visceral fat effected some improvement in insulin resistance and glucose metabolism. Because the effect was relatively minimal compared with that of gastric banding, visceral fat resection combined with gastric banding did not appear to exert additional effects on insulin resistance and glucose metabolism compared with gastric banding alone.