Sarcopenia, similar to hypercortisolism, is characterized by loss of muscle mass and strength. Cortisol circadian rhythm changes with aging (blunted late-day nadir values) were suggested to contribute to this decline. We aimed to explore the relationship between diurnal salivary cortisol values and sarcopenia diagnosis and its components in postmenopausal women. This is a cross-sectional study within the OsteoLaus population-based cohort in Lausanne (Switzerland). Participants had a body composition assessment by dual X-ray absorptiometry (DXA), a grip strength (GS) measure, and salivary cortisol measures (at awakening, 30 min thereafter, 11 AM (sc-11AM) and 8 PM (sc-8PM)). Associations between salivary cortisol and sarcopenia diagnosed by six different criteria (based on appendicular lean mass (ALM) assessed by DXA, and muscle strength by GS), and its components, were analyzed. 471 women aged > 50 years (63.0 ± 7.5) were included. Various definitions identified different participants as sarcopenic, who consistently presented higher salivary cortisol at 11 AM and/or 8 PM. There were no associations between salivary cortisol levels and ALM measures, either absolute or after correction to height squared (ALM index) or body mass index. GS was inversely correlated to sc-11AM (r = − 0.153, p < 0.001) and sc-8PM (r = − 0.118, p = 0.002). Each 10 nmol/l increase of sc-11AM, respectively sc-8PM, was associated with a GS decrease of 1.758 (SE 0.472) kg, respectively 2.929 (SE 1.115) kg. In postmenopausal women, sarcopenia is associated with higher salivary cortisol levels at 11 AM and 8 PM. An increase of daily free cortisol levels in the physiological range could participate to sarcopenia development by decreasing muscle function in postmenopausal women.

肌肉减少症，类似于皮质醇增多症，其特征是肌肉质量和力量的丧失。皮质醇昼夜节律随着年龄的增长而变化（迟钝的最低点值）被认为是导致这种下降的原因。我们旨在探讨绝经后女性的昼夜唾液皮质醇值与肌肉减少症诊断及其成分之间的关​​系。这是一项在洛桑（瑞士）的 OsteoLaus 人群队列中进行的横断面研究。参与者通过双 X 射线吸收测定法 (DXA)、握力 (GS) 测量和唾液皮质醇测量（醒来时、此后 30 分钟、上午 11 点 (sc-11AM) 和晚上 8 点 (sc-8PM) 进行身体成分评估） ））。唾液皮质醇与通过六种不同标准诊断的肌肉减少症之间的关联（基于 DXA 评估的四肢瘦体重 (ALM) 和 GS 的肌肉力量），及其组成部分进行了分析。包括 471 名年龄 > 50 岁 (63.0 ± 7.5) 的女性。各种定义将不同的参与者确定为肌肉减少症，他们在上午 11 点和/或晚上 8 点始终表现出较高的唾液皮质醇。唾液皮质醇水平与 ALM 测量值之间没有关联，无论是绝对值还是校正到身高平方（ALM 指数）或体重指数后。GS 与 sc-11AM 呈负相关（r  = - 0.153, p  < 0.001) 和 sc-8PM ( r  = - 0.118, p  = 0.002)。sc-11AM 和 sc-8PM 每增加 10 nmol/l，GS 分别减少 1.758 (SE 0.472) kg 和 2.929 (SE 1.115) kg。在绝经后妇女中，肌肉减少症与上午 11 点和晚上 8 点时唾液皮质醇水平升高有关。生理范围内每日游离皮质醇水平的增加可通过降低绝经后妇女的肌肉功能来参与肌肉减少症的发展。