Physiological interindividual variability in endogenous estradiol concentration does not influence adipose tissue and hepatic lipid kinetics in women

Sex-Specific Differences in Lipoprotein Production and Clearance

Therapeutic approaches to reduce atherogenic lipid and lipoprotein levels remain the most effective and assessable strategies to prevent and treat cardiovascular disease. The discovery of novel research targets linked to pathways associated with cardiovascular disease development has enhanced our ability to decrease disease burden; however, residual cardiovascular disease risks remain. Advancements in genetics and personalized medicine are essential to understand some of the factors driving residual risk. Biological sex is among the most relevant factors affecting plasma lipid and lipoprotein profiles, playing a pivotal role in the development of cardiovascular disease. This minireview summarizes the most recent preclinical and clinical studies covering the effect of sex on plasma lipid and lipoprotein levels. We highlight the recent advances in the mechanisms regulating hepatic lipoprotein production and clearance as potential drivers of disease presentation. We focus on using sex as a biological variable in studying circulating lipid and lipoprotein levels.

Understanding the female athlete: molecular mechanisms underpinning menstrual phase differences in exercise metabolism

Research should equitably reflect responses in men and women. Including women in research, however, necessitates an understanding of the ovarian hormones and menstrual phase variations in both cellular and systems physiology. This review outlines recent advances in the multiplicity of ovarian hormone molecular signaling that elucidates the mechanisms for menstrual phase variability in exercise metabolism. The prominent endogenous estrogen, 17-β-estradiol (E2), molecular structure is bioactive in stabilizing plasma membranes and quenching free radicals and both E2 and progesterone (P4) promote the expression of antioxidant enzymes attenuating exercise-induced muscle damage in the late follicular (LF) and mid-luteal (ML) phases. E2 and P4 bind nuclear hormone receptors and membrane-bound receptors to regulate gene expression directly or indirectly, which importantly includes cross-regulated expression of their own receptors. Activation of membrane-bound receptors also regulates kinases causing rapid cellular responses. Careful analysis of these signaling pathways explains menstrual phase-specific differences. Namely, E2-promoted plasma glucose uptake during exercise, via GLUT4 expression and kinases, is nullified by E2-dominant suppression of gluconeogenic gene expression in LF and ML phases, ameliorated by carbohydrate ingestion. E2 signaling maximizes fat oxidation capacity in LF and ML phases, pending low-moderate exercise intensities, restricted nutrient availability, and high E2:P4 ratios. P4 increases protein catabolism during the luteal phase by indeterminate mechanisms. Satellite cell function supported by E2-targeted gene expression is countered by P4, explaining greater muscle strengthening from follicular phase-based training. In totality, this integrative review provides causative effects, supported by meta-analyses for quantitative actuality, highlighting research opportunities and evidence-based relevance for female athletes.

Effects of a high-fat meal on inflammatory and endothelial injury biomarkers in accordance with adiposity status: a cross-sectional study

Background

It is known that consuming a high-fat meal (HFM) induces microvascular dysfunction (MD) in eutrophic women and aggravates it in those with obesity. Our purpose was to investigate if the MD observed after a single HFM intake is caused by endothelial damage or increased inflammatory state, both determined by blood biomarkers.

Methods

Nineteen women with obesity (BMI 30-34.9 kg/m²) and 18 eutrophic ones (BMI 20.0-24.9 kg/m²) were enrolled into two groups: Obese (OBG) and Control (CG), respectively. Blood samples were collected at five-time points: before (fasting state) and 30, 60, 120, and 180 min after HFM intake to determine levels of adipokines (adiponectin, leptin), non-esterified fatty acid (NEFA), inflammatory [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)] and endothelium damage [soluble E-selectin, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor-1 (PAI-1)] biomarkers.

Results

Levels of soluble E-selectin, leptin, and PAI-1 were higher in OBG at all-time points (P < 0.05) compared to CG. In the fasting state, OBG had higher levels of NEFA compared to CG (P < 0.05). In intra-group analysis, no significant change in the levels of circulating inflammatory and endothelial injury biomarkers was observed after HFM intake, independently of the group.

Conclusion

Our findings suggest that women with obesity have an increased pro-inflammatory state and more significant endothelial injury compared to eutrophic ones. However, the consumption of a HFM was not sufficient to change circulating levels of inflammatory and endothelial injury biomarkers in either group.

Registration number for clinical trials:

NCT01692327.