Ovarian Lipid Metabolism Modulates Circulating Lipids in Premenopausal Women

Abstract

<div class="section"> <a class="named-anchor" id="s1"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e175">Context:</h5> <p id="d6905037e177">The premenopausal circulating lipid profile may be linked to the hormonal profile and ovarian lipid metabolism. </p> </div><div class="section"> <a class="named-anchor" id="s2"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e180">Objective:</h5> <p id="d6905037e182">Assess how estradiol, progesterone, and ovarian lipid metabolism contributes to the premenopausal lipid profile; and evaluate the acute effects of a common hormonal oral contraceptive (OC) on circulating lipids. </p> </div><div class="section"> <a class="named-anchor" id="s3"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e185">Design:</h5> <p id="d6905037e187">Experimental crossover with repeated measures.</p> </div><div class="section"> <a class="named-anchor" id="s4"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e190">Setting:</h5> <p id="d6905037e192">Academic hospitals.</p> </div><div class="section"> <a class="named-anchor" id="s5"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e195">Patients:</h5> <p id="d6905037e197">Eight healthy, regularly menstruating women.</p> </div><div class="section"> <a class="named-anchor" id="s6"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e200">Interventions:</h5> <p id="d6905037e202">Participants underwent periodic serum sampling during a normal menstrual cycle; a standard 21-day, monophasic combined hormonal OC cycle (30 µg of ethinyl estradiol and 150 µg of levonorgestrel per day); menopause simulated by leuprolide acetate (22.5-mg depot); and an artificial menstrual cycle achieved via transdermal estradiol (50 to 300 µg/d) and vaginal micronized progesterone (100 to 300 mg/d). </p> </div><div class="section"> <a class="named-anchor" id="s7"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e205">Main Outcome Measures:</h5> <p id="d6905037e207">Primary outcomes included evaluation of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, triglycerides, and the total cholesterol to HDL cholesterol ratio. To estimate the effect of estradiol, progesterone, and ovarian lipid metabolism, all specimens except those from the OC cycle were analyzed. Subgroup analysis was conducted on the follicular and luteal phases. In a separate analysis, the effect of the OC was evaluated relative to the normal menstrual cycle. </p> </div><div class="section"> <a class="named-anchor" id="s8"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e210">Results:</h5> <p id="d6905037e212">Estradiol was significantly associated with increased levels of HDL cholesterol throughout the menstrual cycle and in the follicular phase. Ovarian effects were associated with reduced lipid levels, especially during the luteal phase. The OC was associated with an increased total cholesterol to HDL cholesterol ratio and triglycerides. </p> </div><div class="section"> <a class="named-anchor" id="s9"> <!-- named anchor --> </a> <h5 class="section-title" id="d6905037e215">Conclusion:</h5> <p id="d6905037e217">Previously unappreciated factors including ovarian lipid metabolism may contribute to the premenopausal lipid profile. </p> </div><p class="first" id="d6905037e220">We studied how estradiol, progesterone, and ovarian effects mediate circulating lipids in premenopausal women and found a novel role for the corpus luteum in reducing low-density lipoprotein cholesterol. </p>