Multidimensional Determinants of Functional Health In Women Aged 45-60

This is a single-center, cross-sectional observational study designed to evaluate the multidimensional determinants of functional health in women aged 45 to 60 years. The study will be conducted at the Department of Obstetrics and Gynecology, Kartal Dr. Lütfi Kırdar City Hospital, Istanbul, Turkey.

Midlife and the menopausal transition are associated with changes in muscle strength, bone mineral density, body composition, metabolic profile, physical performance, sleep quality, mood, and menopause-related symptoms. Functional health is a multidimensional construct encompassing physical capacity, independence in daily activities, psychological well-being, and health-related quality of life. This study will assess functional health using biological, behavioral, psychological, and symptom-related indicators rather than relying on a single test or questionnaire score.

Inclusion Criteria are:

* Women aged 45 to 60 years * Ability to read and complete study questionnaires * Provision of written informed consent * Ability to complete physical performance assessments

Exclusion Criteria are:

* Acute systemic illness * Active malignancy * Severe neurological or orthopedic impairment limiting physical performance assessment * Cognitive impairment precluding informed consent or questionnaire completion Eligible participants will be evaluated during a single outpatient visit. After written informed consent is obtained, demographic and clinical data will be recorded. These data will include age, marital status, obstetric history, socioeconomic status, menopausal status and duration, body mass index, comorbidities, medication use, and lifestyle characteristics.

Muscle strength and physical performance will be assessed using handgrip strength measurement with a dynamometer and the 30-second chair stand test. Anthropometric measurements, including body weight and waist circumference, will be obtained. Body composition will be assessed using a bioelectrical impedance analysis device.

Bone health will be evaluated using dual-energy X-ray absorptiometry data. Existing bone mineral density data obtained within the previous 6 months will be used, and no repeat DXA assessment will be carried out. Laboratory parameters include complete blood count, 25-hydroxyvitamin D, vitamin B12, ferritin, liver function tests, lipid profile, glucose-related parameters, HbA1c, and/or HOMA-IR.

Participants will complete validated questionnaires assessing physical activity, vulvovaginal symptoms, menopausal symptoms, menopause-specific quality of life, general health-related quality of life, depressive symptoms, and sleep quality. The questionnaires planned for use include the International Physical Activity Questionnaire-Short Form, Vulvovaginal Symptoms Questionnaire, Menopause Rating Scale, Menopause-Specific Quality of Life Questionnaire-II, SF-36 Health Survey, Beck Depression Inventory, and Pittsburgh Sleep Quality Index.

Data will be collected using standardized case report forms. Questionnaire forms will be provided by the principal investigator and completed by the participants during the study visit. Physical performance tests will be performed in the outpatient clinic by the principal investigator. Body composition measurements will be performed by the co-investigator.

Data quality will be supported by predefined study variables, standardized data-collection forms, and consistency checks during data entry. The database will be reviewed for missing, out-of-range, or inconsistent values. When a variable is unavailable in the medical record, it will be coded as missing. No imputation is planned for unavailable variables; analyses will be conducted using available data, and the number of participants included in each analysis will be reported.

Approximately 200 women are planned for inclusion. This sample size was selected to allow multivariable analyses and structural equation modeling. The planned model is expected to include approximately 15 to 20 observed variables and 20 to 25 free parameters. A minimum sample size of approximately 180 participants was estimated based on the recommended ratio of participants to free parameters in structural equation modeling. Therefore, enrollment of at least 200 participants is planned to improve model stability and allow reliable estimation of model fit indices.

Descriptive statistics will be used to summarize demographic, clinical, functional, densitometric, laboratory, and questionnaire-based variables. Associations between variables will be evaluated using correlation analyses and multivariable regression models. Age, body mass index, menopausal duration, and comorbidities will be considered as covariates. Statistical significance will be set at p \< 0.05. Structural equation modeling will be used to examine the structural relationships among muscle health, bone health, body composition, physical activity, sleep quality, depressive symptoms, menopausal symptoms, and functional health.

The study is expected to provide a multidimensional model of functional health in women aged 45 to 60 years and to clarify the independent contribution of muscle and bone health to functional capacity and health-related quality of life during midlife.

• Bone Mineral Density measured by DXA (g/cm²) [Time frame: Baseline]
• Hand-Grip Strength measured by hydraulic hand dynamometer (kg) [Time frame: Baseline]
• Lower Extremity Functional Strength assessed by 30-Second Chair Stand Test (number of repetitions) [Time frame: Baseline]
• Total Body Fat Mass measured by BIA (kg) [Time frame: Baseline]
• Total Body Fat Percentage measured by BIA (%) [Time frame: Baseline]
• Fat-Free Mass measured by BIA (kg) [Time frame: Baseline]
• Skeletal Muscle Mass measured by BIA (kg) [Time frame: Baseline]
• Total Body Water measured by BIA (litres) [Time frame: Baseline]
• Body Mass Index (BMI) calculated from measured height and weight (kg/m²) [Time frame: Baseline]
• Physical Component Summary Score of SF-36 (units on a scale 0-100) [Time frame: Baseline]
• Mental Component Summary Score of SF-36 (units on a scale 0-100) [Time frame: Baseline]
• Menopause-Specific Quality of Life (MENQOL) Total Score (units on a scale 1-8) [Time frame: Baseline]