Extensive research has been carried out on the association of cortisol levels and cognitive function but, to date, there is still little agreement on this relationship. Dysregulated hormonal balance and, in particular, impaired diurnal cortisol secretion is hypothesized as one of the underlying mechanisms for cognitive decline among the elderly.
H. Johar (left), K.-H. Ladwig (right), Source: Helmholtz Zentrum München
Dysregulated cortisol secretion is associated with cognitive impairment in men
“Chronic exposure to glucocorticoid (cortisol in human) is neurotoxic and with advancing age, hypercortisolemia-induced neuroendocrine changes may contribute to deleterious effects on the hippocampus which can affect memory performance and lead to cognitive decline,” said Prof. Dr. Karl-Heinz Ladwig, head of the Mental Health working group at the Institute of Epidemiology II at HMGU. “Our findings showed dysregulated cortisol secretion, as featured by a lower morning to late in the evening cortisol level ratio, was significantly associated with cognitive impairment in men.”
In this study, researchers conducted a cross-sectional analysis of 733 participants from the KORA-Age Study which examines the health status in people aged 65 years or older in the area of Augsburg, Germany. Cortisol levels were measured using saliva samples at three points: awakening, 30 minutes after awakening and evening. Cognitive status was determined by the telephone interview for cognitive status-modified (TICS-m).
Sex-specific association demonstrated for the first time
“The sex-specific associations of lower morning to evening cortisol level ratios, with poorer cognitive function in men and not women, have not been previously reported in epidemiological studies”, said Hamimatunnisa Johar, a PhD student and first author of the study. “Men were also known to perform worse in the memory task than women which may also influence the observed associations in men.”
Hormonal secretion is a target for new intervention strategies
This study presents evidence for the relationship between cognitive function and blunted cortisol reactivity with advancing age. Thus, variability of diurnal cortisol secretion may provide crucial information for an underlying mechanism of cognitive decline. Furthermore, the ability to identify individuals who are most at risk for progressing to dementia is important to develop intervention strategies to combat reduction in cognitive performance.
The aim of the Helmholtz Zentrum München is to develop new approaches for the diagnosis, therapy and prevention of common diseases.
* TICS-m: telephone interview for cognitive status-modified
Other authors of the study include: Rebecca Emeny, Margit Heier, and Annette Peters of Helmholtz Zentrum München, Martin Bidlingmaier and Martin Reincke of Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Ludwig Maximilians Universität München, and Maria Elena Lacruz of Martin Luther Universität Halle.
Johar, H. et al. (2015), Lower morning to evening cortisol ratio is associated with cognitive impairment in men but not women: an analysis of 733 older subjects of the cross-sectional KORA-Age study. Psychoneuroendocrinology, 51 (296–306), doi: 10.1210/jc.2013
Helmholtz Zentrum München, as German Research Center for Environmental Health, pursues the goal of developing personalized medical approaches for the diagnosis, treatment and prevention of major widespread diseases such as diabetes mellitus and lung diseases. To achieve this, it investigates the interaction of genetics, environmental factors and lifestyle. The head office of the Center is located in Neuherberg in the north of Munich. Helmholtz Zentrum München has a staff of about 2,200 people and is a member of the Helmholtz Association, a community of 18 scientific-technical and medical-biological research centers with a total of about 34,000 staff members.
The Institute of Epidemiology II (EPI II) focuses on the assessment of environmental and lifestyle risk factors which jointly affect major chronic diseases such as diabetes, heart disease and mental health. Research builds on the unique resources of the KORA cohort, the KORA myocardial infarction registry, and the KORA aerosol measurement station. Aging-related phenotypes have been added to the KORA research portfolio within the frame of the Research Consortium KORA-Age. The institute’s contributions are specifically relevant for the population as modifiable personal risk factors are being researched that could be influenced by the individual or by improving legislation for the protection of public health.
For more than 20 years, the research platform Cooperative Health Research in the Augsburg Region (KORA) has been collecting and analyzing data on the health of thousands of people living in the Augsburg region. The objective is to elucidate the effects of environmental factors, behavior and genes. KORA focuses on the development and course of chronic diseases, in particular myocardial infarction and diabetes mellitus. Risk factors are analyzed with regard to individual health behavior (e.g. smoking, diet, exercise), environmental factors (e.g. air pollution, noise) and genetics. From the perspective of health care research, questions regarding the utilization of health care resources and the cost of health care are also studied.