Author(s): ANZAI, M., SHIOSE, K.2, KAWAKAMI, S.3, TSUDA, E.4, NAKASHIMA, S.4, KOMATSU, T.5, HIGAKI, Y.4, UEHARA, Y.4,5, MICHISHITA,R.4, Institution: FUKUOKA UNIVERSITY, Country: JAPAN, Abstract-ID: 1641

INTRODUCTION:
Women have a menstrual cycle that is characterized by large differences in the serum concentrations of ovarian hormones, such as estrogen and progesterone. Changes in sex hormone associated with menopause and ageing have been suggested to be linked to a reduction in skeletal muscle mass. However, association of skeletal muscle quality with sex hormones levels of young women remain insufficiently investigated. Phase angle (PhA) measured using the bioelectrical impedance spectroscopy (BIS) method reflects cell integrity and body hydration status, indicating qualitative characteristics of body composition, has garnered increased attention. This study focused on the PhA measured by BIS as an indicator of skeletal muscle quality. This study aimed to clarify the association with skeletal muscle quality and sex hormone levels in young women.
METHODS:
The participants included 34 young women (age, 20.7 ± 1.5 years). The participants underwent examinations under overnight fasting conditions in the morning for 3 to 7 days during menstruation. Considering the impact of water content, intake was standardized to 280 mL in the examination morning. Fat-free mass (FFM), fat mass (FM), and PhA were measured using the BIS. Blood samples were collected in the morning after a 12-h overnight fast, and follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, progesterone and estradiol (E2) were measured. Nutritional status was assessed using the Brief-Type Self-Administered Diet History Questionnaire. Cut-off value for PhA (Skeletal muscle quality) was defined as 5.02°, according to previous studies [1]. We investigated the participants into two groups based on the cut-off value for skeletal muscle quality (low-PhA group and high-PhA group) and investigated the association with sex hormone levels in young women.
RESULTS:
The low-PhA group had significantly lower LH and testosterone levels than the high-PhA group (P < 0.05, respectively). However, the low-PhA group consumed more the proportions of protein intake per total energy intake than the high-PhA group (P < 0.05). FFM, FM, total energy intake, FSH, progesterone and E2 were not significantly different between two groups.
CONCLUSION:
These results suggest that a possible decline in skeletal muscle quality may be associated with reduced sex hormones levels in young women, regardless of the ratio of protein intake to total energy intake. Our findings support a relationship between skeletal muscle quality and sex hormones levels in young women suggest that further investigation is warranted, both for validation, further exploration and to gain a deeper understanding of the mechanisms and potential consequences for health.
References
1. Akamatsu et al. J Cachexia Sarcopenia Muscle. 2022.