Physical activity as a part of the lifestyle is a significant factor influencing health condition. Exercises that require stamina are of particular importance. Oxygen metabolism, which is a significant part of all longer training processes, has an influence on cardiovascular and respiratory system functioning as well as all the processes taking part in maintenance of efficient homeostasis. Presentation of the correlation between exercise test results and MMP-8 (metalloproteinase-8) and TIMP-1 (tissue inhibitor of metalloproteinases-1) levels was attempted in this work. MMP-8 is a proteolytic enzyme taking part in progression of diseases related to process of ageing. 62 healthy women in postmenopausal period were qualified for the study (mean age:
Systematic physical activity improves expression of genes which influence health condition [
The postmenopausal period is a special time in women’s life. Aside from frequent occurrence of typical ailments [
The aim of the study is to assess the connection between physical capacity measured with exercise test and indicator of early vascular changes, increased matrix metalloproteinase (MMP), and its inhibitor activity, in clinically healthy women in postmenopausal period. Matrix metalloproteinases are the main proteolytic enzymes responsible for apoptosis and angiogenesis. They are involved in pathogenesis of diseases related to the process of ageing, such as arthritis, atherosclerosis, and neoplasms [
The examined group consisted of 62 Caucasian women in the postmenopausal period at the age of
Methods used in the study included history taking, physical examination, exercise test, and assessing activity of metalloproteinase-8 (MMP-8) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in serum. Women were defined as postmenopausal according to following criteria: (1) duration of amenorrhea > 12 months and (2) blood concentration of follicle stimulating hormone (FSH) > 30 IU/mL [
Medical history data and physical examination results were registered in a questionnaire. Waist circumference was measured; body mass index (BMI) and waist-hip ratio (WHR) were calculated. Waist circumference was taken as the minimum circumference between the umbilicus and the xiphoid process and measured to the nearest 0.5 cm. BMI was calculated as weight in kilograms divided by the square of height in meters.
ECG exercise stress tests were performed with the treadmill stress test (GE Medical Systems, Freiburg, Germany) according to Bruce’s protocol [
Metalloproteinase-8 (MMP-8) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in blood serum were assessed with immunosorbent tests using ELISA method with R&D Systems kits (Minneapolis, MN 55413, USA). Blood samples at rest, before exertion, were taken between 10 a.m. and 1 p.m. Blood level of metalloproteinase-8 (MMP-8) was assessed with kit whose catalogue number was DMP800; tissue inhibitor of metalloproteinase (TIMP-1) level was assessed with kit with catalogue number DTM100. Producer’s instructions were followed. In every case calibration curve was made. Examination results were assessed with III universal microplatelets reader Bio-Tek ELX 800. Blood levels of MMP-8 and TIMP-1 were measured in ng/mL.
Data were processed using Statistica 10 (StafSoft) computer programme. Data are shown as means ± standard deviation (SD). Correlations between selected parameters were calculated using nonparametric test (
The procedures of investigation were in accordance with the ethical standards of the responsible committee on human experimentation (Committee on Bioethics, Medical University of Lublin, KE-0254/185/2006) and with the Helsinki Declaration of 1975, as revised in 1983.
The group of 62 women in the postmenopausal life period, confirmed by FSH level higher than 30 IU/mL, was examined. Mean menopause duration was 4.7 ± 4.5 years. The anthropometric data of studied group are presented in Table
General characteristics of the examined group (
Age (years) | |
Height (cm) | |
Weight (kg) | |
BMI (kg/m2) | |
Waist circumference (cm) | |
Waist-hip ratio | |
Exercise test results in examined group of women in postmenopausal period (
Exercise test duration (min) | |
MET | |
HR at rest (beats/min) | |
SBP at rest (mm Hg) | |
DBP at rest (mm Hg) | |
HR reached during exercise (beats/min) | |
HR increase during exercise (beats/min) | |
HR max (beats/min) | |
HR during exercise/HR max (%) | |
SBP reached during exercise (mm Hg) | |
DBP reached during exercise (mm Hg) | |
SBP increase during exercise (mm Hg) | |
DBP increase during exercise (mm Hg) | |
SBP: systolic blood pressure; DBP: diastolic blood pressure; HR: heart rate; MET: metabolic equivalent of task.
Mean metalloproteinase-8 level in blood serum in the examined group was
Exercise test parameters correlation with MMP-8 and TIMP-1 concentration in examined group of women in postmenopausal period (
MMP-8 (ng/mL) | TIMP-1 (ng/mL) | |||
---|---|---|---|---|
| | | | |
Exercise test duration (min) | −0.237 | 0.226 | −0.138 | 0.551 |
MET | −0.103 | 0.601 | −0.326 | 0.138 |
HR at rest (beats/min) | 0.187 | 0.340 | 0.120 | 0.594 |
HR reached during exercise (beats/min) | −0.047 | 0.814 | | 0.045 |
HR increase during exercise (beats/min) | | 0.004 | | 0.004 |
SBP at rest (mm Hg) | 0.224 | 0.252 | −0.074 | 0.744 |
DBP at rest (mm Hg) | 0.343 | 0.074 | −0.262 | 0.239 |
SBP reached during exercise (mm Hg) | −0.090 | 0.650 | −0.076 | 0.738 |
DBP reached during exercise (mm Hg) | 0.306 | 0.113 | 0.074 | 0.744 |
SBP increase during exercise (mm Hg) | −0.225 | 0.270 | 0.203 | 0.379 |
DBP increase during exercise (mm Hg) | 0.074 | 0.718 | 0.153 | 0.508 |
SBP: systolic blood pressure; DBP: diastolic blood pressure; HR: heart rate; MET: metabolic equivalent of task.
MMP-8 and TIMP-1 in relation to exertional heart rate increase. MMP-8: matrix metalloproteinase-8; TIMP-1: tissue inhibitor of metalloproteinases; HR: heart rate.
Research on connection between active lifestyle and chosen physiological, structural, and biochemical parameters contributes to recognizing mechanisms of chronic diseases, such as cardiovascular diseases, which are the main cause of death and disability in group over 50 years old. Physical training improves the endothelium function [
Clinical course of ischemic heart disease in women in postmenopausal period is specific. More often there are microcirculatory abnormalities, whose sign is positive electrocardiographic exercise test with no significant hemodynamic changes in the epicardial arteries. What is more, false positive and false negative results of the exercise test are more frequent, what limits usefulness of this examination in diagnostics of ischemic heart disease among women in postmenopausal period [
One of the cardiovascular risk factors is low physical activity, which may modify exercise test results by influencing physical capacity of women after menopause. That is why the question regarding whether there is a correlation between exercise test results and early biochemical indicators of pathological process within the arteries remains to be answered. These indicators include metalloproteinases, enzymes which take part in extracellular matrix remodeling. They are secreted as proenzymes and activated by proteinases, plasmin, trypsin, chymotrypsin, kallikrein, cathepsin, and some MMPs. The main sources of all metalloproteinases are inflammatory cells [
Metalloproteinases activity may be moderated by tissue inhibitors, which include TIMP-1. Metalloproteinases inactivation is based on forming complexes which consist of active forms of MMP or some proenzymes and tissue inhibitor, complexes MMP-TIMP [
In the atherosclerotic lesions MMP-8 expression was found. MMP-8 inactivation in experiments conducted on mice causes significant decrease of atherosclerotic lesions formation. Genetic knockout of MMP-8 in mice also results in lower angiotensin II concentration, lower blood pressure, and decrease of adhesive molecules number in atherosclerotic plaque, which lowers leucocytes adhesion to the endothelium. These data indicate an important role of MMP-8 in atherosclerosis process [
To our best knowledge, there have not been any researches indicating correlations between exercise test results and metalloproteinases and their inhibitors blood levels in clinically healthy women in postmenopausal period yet. Confirmation of results of this study and their practical usefulness demand further research on bigger group of women.
Increased level of MMP-8 in serum is correlated with lower heart rate increase in exercise test in women in postmenopausal period. Tissue inhibitor of metalloproteinases activity is higher among women in postmenopausal period who present lower maximal heart rate and lower heart rate increase in exertion. These changes may constitute evidence of pathological process within the arteries in women with lower than common for this group physical capacity.
The authors declare that there is no conflict of interests regarding the publication of this paper.