(47) WHAT IN THE HEALTH IS GOING ON IN PERIMENOPAUSE: AN EVALUATION OF BODY COMPOSITION, PHYSICAL ACTIVITY, AND SYMPTOMS

Purpose: Perimenopause marks a critical period for adverse changes in body composition, including accelerated loss of lean mass (LM), declines in muscle characteristics, such as size (mCSA) and quality (EI), and increases in fat mass (FM) and body fat percentage (BF%). These changes are often compounded by physical and psychological menopause symptoms. Physical activity (PA) plays an important role in overall health and quality of life during perimenopause, with early evidence suggesting a role in mitigating total menopause symptoms (TMS). The purpose of this study was to examine the relationships between body mass index (BMI), body composition (LM, FM, BF%), muscle characteristics (mCSA, EI), PA, and menopause symptom severity (anxiety [ANX], depression [DEP], somatic [SOM], vasomotor [VM]). Methods: Twenty-one generally healthy, perimenopausal women were included in this study (Mean±standard deviation; Age: 49.0±4.3 years, BMI: 31.7±3.2 kg/m²). LM (kg), FM (kg), and BF% were derived via whole-body dual-energy x-ray absorptiometry. Portable brightness ultrasound was used to estimate mCSA (cm²) and EI (a.u.) of the vastus lateralis. Derived from the International Physical Activity Questionnaire, PA intensity levels were reported as moderate (MOD; min/d), vigorous (VIG; min/d), and resistance training (RT; min/d). The Greene Climacteric Scale was used to assess menopause symptom severity across 21 symptoms (0 to 3 Likert scale). All symptom severity scores were summed to create a composite TMS severity score, as well as composite scores for each symptom subset: psychological (PSYCH; combining ANX and DEP), SOM, and VM. A Pearson’s correlation was calculated to assess the relationships across all body composition, muscle characteristics, PA, and menopause symptom severity scores. Linear regression models were used to identify the strongest predictors of TMS severity and severity of symptom subsets. Results: BMI was significantly associated with VM severity (r=0.492, p=0.032), and a trend towards significance appeared between LM and VM severity (r=0.443, p=0.058). RT was associated with PSYCH severity (r=0.460, p=0.048) and DEP severity (r=0.469, p=0.043). Age predicted 28.4% of variance in TMS (p=0.023), increasing to 47.6% with VIG (p=0.033). Age predicted 32.8% of PSYCH variance (p=0.013), increasing to 49.6% with RT (p=0.041). For ANX, age explained 31.5% of the variance (p=0.015), increasing to 49.5% with VIG (p=0.035). In a final enter-method regression model (R²=0.732), mCSA emerged as a significant predictor of ANX severity (p=0.048). For VM severity, BMI explained 27.8% of variance (p=0.025). Conclusions: VIG and RT exercise were significant predictors of lower TMS and PSYCH symptom severity. Muscle size may also modulate ANX severity, accounting for 22.8% of