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