Impact Of Oral Contraceptive Use On Vascular Responses To A High-Fat Meal

Young women who are naturally menstruating have higher concentrations of pro-inflammatory cytokine interleukin-6 (IL-6) during the early follicular (EF) phase of the menstrual cycle, as compared to women taking oral contraceptives (OCPs) during the placebo pill (PP) phase of the OCP pill cycle. Despite these higher concentrations of IL-6, naturally menstruating women and women taking OCPs exhibit similar resting macrovascular function. Following an acute inflammatory stimulus, potential differences or impairments in macrovascular function may present before they are apparent at rest. It is unknown whether there are differences in the macrovascular responses to an acute inflammatory stimulus such as a high-fat meal (HFM) between naturally menstruating women and women taking OCPs. PURPOSE: To compare macrovascular responses to a HFM between young women who are naturally menstruating and women taking OCPs during EF and PP phases. METHODS: Macrovascular function via brachial artery flow-mediated dilation (%FMD, defined as [(peak post-occlusion diameter - baseline diameter)/baseline diameter]*100) before and following HFM was assessed in a sample of 10 young, healthy women who were taking oral contraceptives (OCP, N = 3) or naturally menstruating (NOCP, N = 7). %FMD was measured before (BL), two (2HP), and four (4HP) hours-post HFM ingestion. Main effects of group and HFM were assessed using 2-way ANOVA. RESULTS: %FMD was similar between groups (main effect of group: p = 0.70) at BL (NOCP: 4.2 ± 1.4; OCP: 5.1 ± 3.7), 2HP (NOCP: 4.9 ± 3.1; OCP: 8.3 ± 5.4), and 4HP (NOCP: 7.5 ± 2.0; OCP: 5.5 ± 1.1). There were no significant absolute changes from baseline values of %FMD (ΔFMD) at 2HP and 4HP following HFM (main effect of HFM: p = 0.50) for either group (NOCP: 2HP ΔFMD = +0.69% and 4HP ΔFMD = +3.3%; OCP: 2HP ΔFMD = +3.2% and 4HP ΔFMD = +0.35%). CONCLUSION: Responses to an acute inflammatory stimulus (HFM) are similar between OCP and NOCP. Neither group appear to experience declines in vascular function following HFM. Supported by UMD Graduate School Faculty Student Research Award (Ranadive, Blake)