Stress Hormone Linked to Frailty
Low levels of cortisol in the morning and high levels in the evening are associated with declining grip strength and walking speed, which are indications of frailty in older adults. That is the finding of research done at Helmholtz Zentrum München in Neuherberg in Germany and published in the March 2014 issue of the Journal of Clinical Endocrinology & Metabolism.
A release from the Endocrine Society notes that frailty confers a high risk for institutionalization and increased risk of mortality and is characterized by unintentional weight loss, feelings of exhaustion and fatigue, physical inactivity, slow gait speed, and low grip strength. Neuroendocrine function, including cortisol secretion, is thought to be involved in the etiology of frailty but until now the underlying biological mechanisms have not been well understood.
The release quotes author Heinz Ladwig, PhD, MD as saying, “Cortisol typically follows a distinct daily pattern with the highest level in the morning and the lowest basal level at night. Our findings showed dysregulated cortisol secretion, as featured by a smaller morning to evening cortisol level ratio, was significantly associated with frailty status.”
In this study, researchers conducted a cross-sectional analysis of 745 participants between the ages of 65 and 90 years. Cortisol levels were measured using saliva samples at three points: awakening, 30 minutes after awakening and evening. Participants were classified as frail if three or more of the following criteria were met: exhaustion, physical inactivity, low walking speed, weakness (measured by grip strength) or weight loss (loss of more than 5 kilograms in the previous six months).
“Our results suggest a link between disrupted cortisol regulation and loss of muscle mass and strength, as the underlying pathophysiology of frailty,” said Hamimatunnisa Johar, a PhD student at Helmholtz Zentrum München and an author of the study. “In a clinical setting assessment of frailty can be time-consuming, and our findings show measurements of cortisol may offer a feasible alternative.”
Other authors of the study include: Rebecca Emeny, Barbara Thorand, Annette Peters and Margit Heier of Helmholtz Zentrum München, German Research Centre for Environmental Health in Neuherberg, Germany; and Martin Bidlingmaier and Martin Reincke of Klinikum der Ludwig-Maximilians-Universität München in Munich, Germany.