Assessing menstrual fluid as a diagnostic tool for diabetes and cardiovascular disease risk in healthy menstruating women : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand

Abstract

Background: Women make up roughly half the global population (49.6%), yet women’s health continues to be vastly underrepresented in medical research. Prevalence of chronic conditions including type 2 diabetes (T2D) and cardiovascular disease (CVD) is increasing, particularly among reproductive aged women. Menstrual fluid (MF), a routinely available biological sample has been growing in interest regarding its use as an alternative health screening tool. Objectives: To assess the agreement between MF and venous blood (VB) for key biomarkers associated with T2D and CVD risk in healthy menstruating women, and to explore the influence of demographic factors (age, body mass index (BMI) and ethnicity) on these biomarkers. Methods: A cross-sectional laboratory study was conducted in 102 premenopausal participants who provided paired MF and VB samples. Biomarkers related to T2D, and CVD were measured using point-of-care testing (POCT) using the COBAS b® 101 analyser. Relative agreement between sample types was assessed using Spearman’s correlation coefficients, and Bland-Altman analysis evaluated absolute agreement, bias and limits of agreement (LoA). Additionally, linear regression models were used to explore whether MF could predict the values of VB biomarkers with addition of covariates (age, BMI, and ethnicity). Results: Findings demonstrated that several biomarkers, including glycated haemoglobin (HbA1c), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), Triglycerides (TG) and TC:HDL ratio, showed moderate to strong association between MF and VB. However, weak absolute agreement was observed between MF and VB biomarkers measurements, and equations using MF results demonstrated limited capacity to predict VB biomarker concentrations, even after adjustment for demographic factors (R² = 0.09 – 0.64). Conclusions: This research provides evidence that MF may be associated with VB across several key health biomarkers used in T2D and CVD PCOT. However, these findings do not support MF as an alternative to VB diagnostics for T2D and CVD risk screening in healthy premenopausal women. Further refinement and validation are needed across a more diverse population to fully understand MF’s clinical potential.