ABSTRACT
The changes of hormonal and autonomic nervous systems in trained and untrained elderly people were studied. An exercise tolerance test was used as a model of physical stress. Elderly people were more sensitive to the influence of stress factors. The hemodynamic reaction at the same workload was more economical in trained subjects. Also, the reaction of the autonomic nervous system and pituitary-adrenal system was less pronounced in trained elderly people. It was established that physical training in aging increases the resistance to stress.
Subject(s)
Adrenal Glands/physiology , Aged/physiology , Autonomic Nervous System/physiology , Exercise Test , Exercise/physiology , Pituitary Gland/physiology , Adrenocorticotropic Hormone/blood , Adult , Blood Pressure , Hemodynamics , Humans , Middle Aged , Models, PsychologicalABSTRACT
We have studied the hormonal and vegetative responses to reactions of exercise in 60 healthy subjects (10 young and 50 old) and in 70 patients with ischemic heart disease (IHD) aged 60-74 years. Plasma levels of cortisol, ACTH, met-enkephalins, leu-enkephalins and beta-endorphins were measured by using radioimmunological methods. The state of autonomic control was determined according to spectral analysis of cardiac rhythm. Compared to the young healthy subjects, the older healthy group had an earlier activation of the ACTH-cortisol system and a more pronounced increase in the sympathetic nervous system during sub-maximal exercise. This could be the reflection of a decreased resistance to stress in older age. The elderly IHD patients showed two types of hormonal reactions to exercise: a rise in the cortisol level and a fall in the met-enkephalins (Group 1), or a fall in the cortisol concentration combined with a rise of met-enkephalins (Group 2). In Group I patients a lower exercise capacity and a less economical reaction of the hemodynamics to a workload of 25 watts was found. An excessive activation of the ACTH-cortisol system and a reduced level of blood met-enkephalins in the elderly IHD patients during exercise are thought to be the unfavourable factors promoting a decrease in tolerance to physical load and an impairment of adaptive capacities of the cardiovascular system.
Subject(s)
Autonomic Nervous System/physiology , Coronary Disease/physiopathology , Exercise/physiology , Hormones/blood , Adaptation, Physiological , Adult , Aged , Cardiovascular System/physiopathology , Electrocardiography , Humans , Middle AgedABSTRACT
30 males, suffering from ischemic heart disease (IHD), and stable exertional angina pectoris, whose age ranged from 60 to 74 years and also 15 apparently healthy volunteers of the same age participated in the study. The IHD patients' blood displayed increased basal levels of adrenocorticotropic hormone (ACTH), cortisol, and met-enkephalins. During graded physical exercise two types of hormonal system response were established: in the first group of patients the plasma ACTH and cortisol levels were seen to rise at maximal threshold load, while in the second group the content of the above hormones declined. The first group of patients showed a less economical hemodynamic response to standard loading in comparison to the second group. A relation was found between changes in hemodynamic system and function of pituitary-adrenal system in elderly IHD patients during physical exercise. Inadequate ACTH and cortisol increase in the course of effects of stress contributed to IHD aggravation in old age, along with reduced tolerance to physical exercise. beta-Adrenoblocker, propranolol, influenced both types of hormonal response, thereby diminishing their shifts in physical stress.
