Poster Topical Area: Aging and Chronic Disease
Poster Board Number: 25
Objectives: Cholecystectomy (XGB), the removal of the gallbladder due to disease, is the most common abdominal surgery performed in the United States. Individuals can survive without a gallbladder, but have an increased prevalence of metabolic syndrome, non-alcoholic fatty liver disease, bile reflux, and insulin resistance. Age (40-50 years old) and sex (female) are two main risks factors for XGB, corresponding with the average onset of menopause in women. Since it is known that post-menopausal estrogen loss exacerbates metabolic dysfunction in women without XGB, the objectives of this pilot study were to: 1) establish a novel model of XGB in intact (SHM) and ovariectomized (OVX) mice, and 2) assess longitudinal effects of loss of ovarian function on metabolism, inflammation, and gastrointestinal (GI) health in XGB mice.
Methods: Eight-wk-old female C57BL/6J mice (N=48) were fed a high-fat (45% kcal), low-sucrose (7% kcal) diet for the entire study (24 wk). BW and food intake were measured weekly. All mice were XGB at wk 0 and either OVX or SHM at wk 6. Body composition was analyzed every 6 wk with EchoMRI. Every 6 wk, 4-8 mice were sacrificed from each group. At sacrifice, serum was collected for lipid profiling and the GI tract, liver, and adipose depots were collected for histomorphology, histopathology, and gene expression analysis.
Results: Preliminary analysis revealed a significant (p<0.01) treatment x wk interaction for BW, body composition, and food intake, with XGB/OVX mice having higher BW at wk 11-23 and increased % fat mass and decreased % lean mass compared to XGB/SHM mice. XGB/OVX mice had higher (p<0.05) hepatic triglyceride (TG) content at wk 24, however blind hepatic lipidosis scoring revealed no significant differences between groups. At wk 12, XGB/OVX mice had greater (p<0.05) subcutaneous and mesenteric fat mass than XGB/SHM mice. Gonadal fat mass tended to be higher (p<0.10) in XGB/OVX mice at wk 12 and 24. Serum total cholesterol tended to be higher (p<0.10) in XGB/OVX mice at wk 12 and serum TG tended to be higher (p<0.10) in XGB/SHM mice at wk 24.
Summary: Findings suggest that loss of ovarian function following XGB results in an increase in fat mass, hepatic steatosis, and serum total cholesterol.
Graduate Research Assistant
Division of Nutritional Sciences, University of Illinois at Urbana-Champaign