Effect of acute heat exposure and heat acclimation on arterial stiffness, oxidative stress and inflammation in healthy young men
Kuupäev
2024-08-21
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Ajakirja pealkiri
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Abstrakt
Kuum keskkond on oluline tegur, mis tõstab südame-veresoonkonna haigustesse haigestumise riski taset ja suremust. Tugev kehaline koormus kõrge temperatuuriga keskkonnas koormab inimese füsioloogilisi süsteeme, vähendab vastupidavuslikku töövõimet ning suurendab kuumarabanduse riski. Aklimatiseerumisel kuumas keskkonnas käivituvad organismis mitmed füsioloogilised kohanemisprotsessid, mille tulemusena kuumastressi taluvus paraneb, terviseriski tase väheneb ja vastupidavuslik töövõime suureneb. Seetõttu on aklimatiseerumisel oluline roll nii spordis kui ka militaarses sfääris.
Arterite jäikuse suurenemine on üks indikaatoreid, mis annab varakult märku kardiovaskulaarse süsteemi talitluse häirumisest. Arterite jäikus iseloomustab arterite laienemisvõimet vererõhu mõjul ja see peegeldab kardiovaskulaarse süsteemi seisundit ning selle süsteemi kohanemist erinevate keskkondlike teguritega. Tugevad kehalised koormused kõrge temperatuuriga keskkonnas võivad suurendada arterite jäikust seoses põletikuliste protsesside intensiivsuse ja oksüdatiivse stressi taseme tõusuga. Seni on väga vähe uuringuid, mis käsitleksid akuutse kuumastressi ja kuumas keskkonnas aklimatiseerumise mõju arterite jäikusele ning oksüdatiivse stressi ja põletiku markeritele.
Käesolev doktoritöö näitab, et akuutne passiivne kuumastress suurendab arterite jäikust ja tõstab põletikumarkeri IL-6 taset, kuid ei mõjuta oksüdatiivse stressi markereid noortel meestel. Seevastu 10-päevasel aklimatiseerumisel kõrge temperatuuriga keskkonnas on arterite jäikust vähendav efekt. Aklimatiseerumisel olulisi seoseid arterite jäikuse muutuse ulatuse, treenituse taseme ja vastupidavusliku töövõime paranemise vahel ei esine. 10-päevane aklimatiseerumine kutsub esile soodsaid muutusi oksüdatiivse stressi ja põletikumarkerite tasemes suutlikkuseni sooritatud vastupidavustööl kuumas keskkonnas.
Antud doktoritöö tulemused aitavad paremini mõista aklimatiseerumise tähtsust kardiovaskulaarse riski vähendamisel raskel kehalisel tööl kõrge temperatuuriga kuumas keskkonnas.
High ambient temperature is an important factor that increases the risk of cardiovascular disease and mortality. Heavy physical exertion in a high-temperature environment puts a strain on a person’s physiological systems, reduces endurance working capacity and increases the risk of heat stroke. During acclimation in a hot environment, several physiological adaptation processes are triggered in the body, as a result of which the tolerance to heat stress improves, the level of health risk decreases and endurance capacity increases. Therefore, acclimation plays an important role both in sports and in the military sphere. Increased arterial stiffness is considered one of the earliest sign of the adverse functional changes of the cardiovascular system. The stiffness of the arteries characterizes the ability of the arteries to expand in response to blood pressure, which reflects the condition of the cardiovascular system, as well as its adaptation to various environmental factors. Heavy physical exertion in a high-temperature environment can increase arterial stiffness due to inflammatory response and increased oxidative stress level. So far, there are very few studies that address the effects of acute heat stress and acclimation in hot environments on arterial stiffness and markers of oxidative stress and inflammation. Present doctoral thesis shows that acute passive heat stress increases arterial stiffness and raises the level of the inflammation marker IL-6, but does not affect markers of oxidative stress in young men. In contrast, 10-day acclimation in a high-temperature environment has a reducing effect on the stiffness of the arteries. There are no significant associations between the extent of the change in arterial stiffness, the subjects’ baseline aerobic fitness level and the improvement in endurance capacity. The 10-day heat acclimation induces beneficial adaptive responses of oxidative stress and inflammation markers to the exhausting endurance exercise in the heat in young men. The results of this doctoral thesis will help to understand the importance of acclimation in reducing cardiovascular risk during heavy physical work in a high-temperature environment.
High ambient temperature is an important factor that increases the risk of cardiovascular disease and mortality. Heavy physical exertion in a high-temperature environment puts a strain on a person’s physiological systems, reduces endurance working capacity and increases the risk of heat stroke. During acclimation in a hot environment, several physiological adaptation processes are triggered in the body, as a result of which the tolerance to heat stress improves, the level of health risk decreases and endurance capacity increases. Therefore, acclimation plays an important role both in sports and in the military sphere. Increased arterial stiffness is considered one of the earliest sign of the adverse functional changes of the cardiovascular system. The stiffness of the arteries characterizes the ability of the arteries to expand in response to blood pressure, which reflects the condition of the cardiovascular system, as well as its adaptation to various environmental factors. Heavy physical exertion in a high-temperature environment can increase arterial stiffness due to inflammatory response and increased oxidative stress level. So far, there are very few studies that address the effects of acute heat stress and acclimation in hot environments on arterial stiffness and markers of oxidative stress and inflammation. Present doctoral thesis shows that acute passive heat stress increases arterial stiffness and raises the level of the inflammation marker IL-6, but does not affect markers of oxidative stress in young men. In contrast, 10-day acclimation in a high-temperature environment has a reducing effect on the stiffness of the arteries. There are no significant associations between the extent of the change in arterial stiffness, the subjects’ baseline aerobic fitness level and the improvement in endurance capacity. The 10-day heat acclimation induces beneficial adaptive responses of oxidative stress and inflammation markers to the exhausting endurance exercise in the heat in young men. The results of this doctoral thesis will help to understand the importance of acclimation in reducing cardiovascular risk during heavy physical work in a high-temperature environment.
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