Metabolic effects of sleeve gastrectomy in female rat model of diet-induced obesity

BackgroundAlthough women disproportionately undergo bariatric surgery, the rodent models investigating the mechanisms of bariatric surgery have been limited to males. Female rodent models can also potentially allow us to understand the effects of surgical intervention on future generations of offspring. Sleeve gastrectomy is an attractive weight loss procedure for reproductive-age female patients because it avoids the malabsorption associated with intestinal bypass. We sought to evaluate the effect of sleeve gastrectomy on young female rats with diet-induced obesity at the University of California, Los Angeles, David Geffen School of Medicine.MethodsSprague-Dawley female rats were fed a 60% high-fat diet. At 12 weeks of age, the rats underwent either sleeve gastrectomy or sham surgery. The rats were killed 4 weeks after surgery. A chemistry panel was performed, and the serum adipokines and gut hormones were assayed. The homeostasis model assessment score was calculated. The liver histologic findings were graded for steatosis. The 2-sample t test was used to compare the results between the 2 groups.ResultsSleeve gastrectomy was associated with significant weight loss (5% ± 6% versus ?4% ± 6%; P < .001), lower leptin levels (1.3 ± 1.2 versus 3.5 ± 2.3 ng/mL; P < .01), and higher adiponectin levels (.43 ± .19 versus .17 ± .14 ng/mL; P < .004) compared with the sham-operated rats. No significant differences were found in the fasting ghrelin levels. Furthermore, we did not observe evidence of insulin resistance or steatohepatitis after 11 weeks of high-fat diet. Despite these limitations, additional gender-specific studies are warranted given that most bariatric surgeries are performed in women.ConclusionSleeve gastrectomy appears to result in weight loss and improvements in adiponectin and leptin by way of mechanisms independent of ghrelin levels in a female model of diet-induced obesity.