Assessment of Metabolic Changes in Response to Glcuose Intake in Women With Polyendocrine Metabolic Ovarian Syndrome (PMOS)

Background and Rationale: Polyendocrine metabolic ovarian syndrome (PMOS), previously referred to as polycystic ovary syndrome (PCOS), is a common endocrine disorder in women of reproductive age. PMOS is characterized by a heterogeneous clinical phenotype involving reproductive, endocrine, and metabolic disturbances, including hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology.

A central feature of PMOS is insulin resistance. Compensatory hyperinsulinemia can enhance ovarian androgen production and reduce hepatic sex hormone-binding globulin synthesis, thereby increasing circulating free androgen levels. This endocrine-metabolic interaction contributes to the reproductive and metabolic manifestations of PMOS.

Beyond reproductive dysfunction, PMOS is associated with impaired glucose metabolism, dyslipidemia, low-grade inflammation, and an increased long-term risk of type 2 diabetes and cardiovascular disease. Metabolic dysfunction in PMOS may not be fully captured by fasting measurements alone, because fasting assessments provide only a static snapshot of systemic physiology.

The oral glucose tolerance test provides a standardized metabolic challenge for assessing dynamic glucose homeostasis. Glucose ingestion induces coordinated physiological responses involving pancreatic insulin secretion, hepatic glucose regulation, peripheral glucose uptake, endocrine adaptation, and immune-metabolic signaling. Dynamic molecular profiling during an oral glucose tolerance test may therefore reveal regulatory abnormalities that are not apparent under fasting conditions.

Plasma represents an integrative biological compartment reflecting metabolic, endocrine, inflammatory, and inter-organ communication processes. Advances in high-resolution molecular profiling now allow simultaneous characterization of circulating metabolites, plasma proteins, steroid hormones, inflammatory mediators, and extracellular vesicle-associated molecular cargo. Extracellular vesicles are of particular interest because extracellular vesicles may contribute to intercellular and inter-organ communication by transporting proteins, nucleic acids, lipids, and metabolites between tissues.

The study is based on the concept that dynamic perturbation testing can provide additional biological information compared with steady-state measurements. A standardized oral glucose tolerance test is used as a controlled metabolic perturbation to characterize systemic molecular response patterns in PMOS and matched control participants.

Study Design: The study is a single-center, exploratory, matched case-control study. Participants with PMOS and age- and body mass index-matched control participants undergo standardized clinical and metabolic assessments. The study is designed to generate high-dimensional molecular data describing dynamic systemic responses to acute glucose ingestion.

Study Procedures: Participants attend a baseline assessment visit and a metabolic challenge visit. The baseline assessment includes clinical characterization, anthropometric measurements, body composition assessment, questionnaire-based phenotyping, and gynecological assessment as applicable.

During the metabolic challenge visit, participants undergo a standardized 75 g oral glucose tolerance test after an overnight fasting period. Blood samples are collected in the fasting state and 2 hours after glucose ingestion. The timing of the metabolic challenge is standardized in the morning, and menstrual cycle timing is controlled where applicable.

Biological Sampling and Molecular Analyses: Blood-derived biospecimens are processed for clinical chemistry and molecular profiling. Plasma is used for metabolomic profiling, proteomic profiling, targeted steroid hormone analysis, inflammatory protein profiling, and extracellular vesicle characterization. Extracellular vesicle analyses include assessment of vesicle concentration, vesicle size distribution, and extracellular vesicle-associated molecular cargo.

Inflammatory and immune-related proteins are measured using a predefined multiplex protein panel. Buffy coat-derived or blood cell-associated material may be used for immune-related analyses, depending on the final laboratory workflow.

Metabolomic analyses focus on circulating small molecules involved in glucose metabolism, lipid metabolism, amino acid turnover, and energy homeostasis. Proteomic analyses focus on circulating proteins related to insulin signaling, inflammatory pathways, lipid metabolism, endocrine regulation, and inter-organ communication. Targeted steroid profiling is performed using mass spectrometry to characterize endocrine regulation in PMOS.

Analytical Approach: The primary analytical focus is the characterization of molecular changes between the fasting state and the post-glucose state. Molecular response patterns are compared between PMOS and matched control participants to identify dynamic differences in metabolic, endocrine, inflammatory, and extracellular vesicle-associated signaling pathways.

The study is exploratory and hypothesis-generating. Integrated analysis of clinical, biochemical, and molecular data is intended to identify systemic response patterns associated with PMOS, insulin resistance, and altered metabolic flexibility.

Inclusion criteria

• Age: 18-35 years
• Body weight (BMI): between BMI 18.5-39.9 kg/m2
• Ability to consent and to provide written informed consent
• CG: History of regular MCs (21 to 35 days) 3 months prior to study enrollment
• PCOS-G: Existing or new established diagnosis of PCOS. Diagnosis is verified in accordance with the ESHRE/ASRM Rotterdam consensus (2003)23, phenotype A (hyperandrogenism, oligo-/anovulation, and polycystic ovarian morphology). PCOS is diagnosed when at least the following three criteria are present, after exclusion of other etiologies:

• Oligo- or anovulation
• Clinical and/or biochemical signs of hyperandrogenism
• Polycystic ovaries on ultrasound (≥12 follicles per ovary measuring 2-9 mm in diameter and/or ovarian volume >10 mL)

Exclusion criteria

• Use of systemic hormonal contraceptives within the last 3 months prior to study enrollment. Use of levonorgestrel-releasing intrauterine devices is permitted; all other hormonal contraceptive methods are excluded.
• CG: A clinically diagnosed or history of a menstrual disorder (e.g., polycystic ovarian syndrome (PCOS), premenstrual dysphoric disorder (PMDD) or amenorrhea)
• A clinically diagnosed mental disorder (e.g. major depression, anxiety disorder)
• history of epileptic seizure
• history of or current manic or psychotic episode
• existing/current eating disorders (bulimia nervosa, anorexia nervosa) within the past 5 years
• inability to communicate adequately in speech
• inability to follow instructions
• regular use of medication other than thyroxine
• alcohol consumption as equivalent doses of more than 12 g of pure alcohol per day
• vegan diet
• daily nicotine consumption
• currently or history of (regular) consumption of illegal drugs within the last year
• pregnancy or breastfeeding
• known diseases of the cardiovascular system
• arterial hypertension above 160/90 mm/Hg at rest
• known pulmonary diseases
• Arthritis and rheumatic diseases and conditions
• Hematologic diseases
• surgery less than 1 month ago
• having given birth within 12 months before the start of the study