The effect of long-term high-fat diet in ovariectomized Wistar rat on leptin serum levels
Abstract: Leptin and estrogen are the hormone that has an important function in energy homeostasis through anorexic effects on the central nervous system. Leptin and estrogen action can decrease food intake, increases energy expenditure and thermogenesis. However, the administration of long-term high-fat diet can lead to impaired leptin function. In addition, estrogen deficiency is also considered a risk factor that may increase the occurrence of obesity in menopause.
Objective: This study is to determine the effect of long-term high-fat diet administration on daily food intake, Lee index, abdominal fat mass and leptin serum levels as a parameter of leptin resistance and obesity in menopause.
Methods: Subject in this study is 28 rats Rattus norvegicus Wistar female 6-8 weeks old, weighing 120-150 grams were divided into 4 groups: OVXSC: groups of rat were ovariectomized and given a standard diet; OVXHF: groups of rat were ovariectomized and given a high-fat diet; SHAMSC: groups of rat were not ovariectomized and given a standard diet; SHAMHF: groups of rat were not ovariectomized and given a high-fat diet. Pre-post test with control group design for measurement of serum leptin levels, food intake, and Lee index. While post-test only control group design for measurement of abdominal fat mass. Statistical analysis was performed by one-way ANOVA and posthoc test of LSD. Pearson test was used to analyze the correlation between leptin serum levels, food intake, Lee index and abdominal fat mass. Paired t-test was used to analyze the differences between values before and after being treated.
Results: The daily food intake dropped in rat fed a high-fat diet, but this reduction was not statistically significant. Ovariectomy in the rat can significantly increase Lee index. Obesity occurs in ovariectomized group, both of high-fat diet (319.38 ± 8.23) and standard diet (312.84 ± 6.94). Abdominal fat mass was significantly higher in high fat compared to standard diet group. Increase in levels of serum leptin highest in OVX-HF group (16.45 ± 8.75 ng / ml), and the lowest in the SHAM-SC (2.98 ± 1.61 ng / ml). There is a significant difference in leptin levels between OVX-HF with OVX-SC group, and between OVX-HF with SHAM-HF group.
Conclusion: Serum leptin levels positively correlated with Lee index and abdominal fat mass, but negatively correlated with daily food intake. Administration of long-term high-fat diet in this study cannot induce leptin resistance.
Author: Dita Fitriani, Andreanyta Meliala, Denny Agustiningsih
Journal Code: jpkedokterangg160185