High-dose oral contraceptives induce hyperinsulinemia without altering immune activation in diet-induced obesity which persists even following a dietary low-fat diet intervention.
Study Goal
The researchers aimed to determine whether switching from a high-fat diet (HFD) to a low-fat diet (LFD) attenuates immunological responses in a rat model of diet-induced obesity, particularly in the context of combined oral contraceptive (COC) use.
Results Summary
The study found that switching from HFD to LFD reduced weight gain and metabolic parameters like triglyceride-glucose index and insulin levels, but insulin levels remained elevated in animals receiving high-dose COC treatment despite the dietary switch. Immunological markers (IL-6 and TNF-α) were also lower in the LFD group compared to HFD.
Population
Female Sprague Dawley rats (n=20, five-week-old) with diet-induced obesity.
Effective Dosage
Not specified for LFD; high-dose COC (HCOC) and low-dose COC (LCOC) were administered but exact dosages not provided.
Duration
Initial diet phase: 8 weeks; dietary switch and COC treatment: 6 weeks.
Interactions
Combined oral contraceptives (COCs) were noted to interact with dietary changes, particularly in metabolic outcomes.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
high-fat diet (HFD) | increase | weight | five-week-old female Sprague Dawley rats | - | significantly gained | #1 |
high-fat diet (HFD) | increase | lee index | five-week-old female Sprague Dawley rats | - | had a higher | #2 |
high-fat diet (HFD) | increase | triglyceride-glucose index | five-week-old female Sprague Dawley rats | - | increased | #3 |
high-fat diet (HFD) | increase | insulin | five-week-old female Sprague Dawley rats | - | increased | #4 |
high-fat diet (HFD) | increase | other metabolic parameters | five-week-old female Sprague Dawley rats | - | increased | #5 |
high-fat diet (HFD) | increase | levels of interleukin (IL)-6 | five-week-old female Sprague Dawley rats | - | elevated | #6 |
high-fat diet (HFD) | increase | levels of tumor necrosis factor-alpha (TNF-α) | five-week-old female Sprague Dawley rats | - | elevated | #7 |
high-dose COC (HCOC) | increase | insulin levels | animals receiving HCOC treatment | - | persistently increased | #8 |
high-dose COC (HCOC) | increase | long-term metabolic dysregulation | rat model of HFD-feeding | - | induces | #9 |
Combined oral contraceptives (COCs) are known to cause weight gain and alter metabolic and immunological pathways. However, modifications in arterial or venous thrombotic risk profiles of women of reproductive ages on COC remain unclear. The study aimed at assessing the impact of COC on immune activation in diet-induced obesity. We further established whether the dietary intervention of switching from a high-fat diet (HFD) to a low-fat diet (LFD) attenuates immunological responses. Twenty (n=20) five-week-old female Sprague Dawley rats were randomly divided into two diet groups of HFD (n=15) and LFD (n=5) and were monitored for eight weeks. After eight weeks, animals in the HFD group switched diets to LFD and were randomly assigned to receive high-dose COC (HCOC) or low-dose COC (LCOC) for six weeks. Animals on HFD significantly gained weight and had a higher lee index when compared to the LFD group (p < 0.05). Moreover, the triglyceride-glucose index, insulin, and other metabolic parameters also increased in the HFD group compared to the LFD group (p < 0.001). Consistently, the levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), were elevated in the HFD group when compared to the LFD group (p < 0.05). Upon switching from a high-fat to a low-fat diet, insulin levels persistently increased in animals receiving HCOC treatment compared to the LFD and HFD/LFD groups (p < 0.05). Thus, in a rat model of HFD-feeding, short-term HCOC treatment induces long-term metabolic dysregulation, which persists despite dietary intervention. However, further studies are recommended to confirm these findings.