Abstract

Arterial hypertension is a pathology caused by the constriction of small vessels, which may be due to the impulses sent from the central nervous system to the smooth muscles of the vessels, or by some substances present in the human organism.
Aim. The aim of the current research was to examine (using statistical models) the conditions of blood circulation in the microcapillary bloodstream, depending on the parameters of muscle tone and their associations with arterial blood pressure.
Method. The research involved 1796 employees from Estonian companies. Synchronously with traditional health monitoring procedures and anthropometrical data collection, the tone of the skeletal muscles was measured myometrically by Myoton-2 elaborated at the University of Tartu. The arterial blood pressure of all employees was measured at health monitoring. The characteristics of tone (natural oscillation frequency of muscles) and elasticity (logarithmic decrement of damping of muscle oscillation) of the following skeletal muscles were recorded bilaterally at the centre of the muscle belly in a relaxed state: m. tibialis anterior, m. extensor digitorum, m. adductor pollicis, m. abductor pollicis brevis, m. flexor carpi radialis, m. gastrocnemius c. med., m. trapezius (two regions – the  upper and the middle parts) and m. erector spinae. The study subjects were distributed into 8 groups according to their gender, age, and body mass index (BMI).
Results. A significant difference in mean arterial blood pressure was noted between all groups (p<0.000001). Blood pressure was higher in people older than 35 years and in those whose BMI was larger than 25 kg/m2.
A positive correlation between arterial blood pressure, age, and body mass index was found for all groups. Arterial blood pressure and logarithmic decrement (characterizing elasticity) as well as oscillation frequency (characterizing tone) of the examined muscles were significantly positively correlated. Increased muscle tone and reduced elasticity was noted in the groups of persons who were older than 35 and/or whose BMI was larger than 25.
Conclusion. It is probable that higher characteristics of muscle tone promote development of hypertension by decreasing the blood flow volume in the microcapillary bloodstream. The results of the study indicated the need to continue the research to clarify the associations between arterial hypertension and the characteristics of the skeletal muscles as assessed comprehensively by myometry and other methods.