| Abstract | Vojni piloti čine specifičan segment populacije vojnih djelatnika, koji su tijekom obavljanja letačkih zadaća izloženi visokim tjelesnim naporima, stresu i buci, što zahtijeva primjerenu psihičku i fizičku spremnost. Dosadašnja istraživanja ukazala su na visoku izloženost zrakoplovne populacije čimbenicima rizika kardiovaskularnih bolesti (KVB) i gubitku sluha, koji uz bolesti lokomotornog sustava predstavljaju najveće zdravstvene rizike. Cilj istraživanja je utvrđivanje povezanosti razine tjelesne spremnosti s čimbenicima rizika KVB i gubitaka sluha u uzorku vojnih pilota, kako bi se mogli planirati preventivni programi za očuvanje zdravlja.
Istraživanjem su izlučeni čimbenici rizika kardiovaskularnih bolesti (KVB), procijenjeno je stanje tjelesne spremnosti, izmjereni su elementi varijabilnosti srčanog ritma (HRV) tijekom upravljanja zrakoplovom, te je određen gubitak sluha u uzorku vojnih pilota.
Razina tjelesne spremnost određena je ergometrijom na pokretnoj traci za varijablu kardiorespiratorne sposobnosti (KRS), testirani su broj učinjenih sklekova i pregiba trupa u dvije minute, izmjereno je vrijeme potrebno za trčanje 2400 metara i izračunao se ukupan broj bodova.
Ispitivani uzorak čini 48 pilota muškog spola u dobi od 35-50 godina, kojima je letenje osnovna, odnosno svakodnevna aktivnost na višenamjenskom helikopteru (Mi-117Sh), školskom zrakoplovu (PC-9), protupožarnom zrakoplovu (Cl-415) i nadzvučnom lovačkom zrakoplovu (Mig-21).
Promatrane varijable čimbenika rizika KVB čine: anamnestički podatci (dob, pušenje, broj sati naleta, podatak o hereditetu KVB), klinički pregled, mjerenja i izračuni indeksa tjelesne mase (ITM), opseg struka, opseg bokova, odnos opsega struka i bokova (WHR), pulsa u mirovanju, sistoličkog i dijastoličkog krvnog tlaka), zatim biokemijski pokazatelji razina u krvi (glukoze, ukupnog kolesterola, LDL kolesterola, HDL kolesterola, triglicerida, visoko osjetljivog C-reaktivnog proteina (CRP-HS i mokraćne kiseline). Pokazatelji razine psihičkog stresa dobiveni su psihološkim testiranjem akutne i kronične komponente (STAI X1 i X2), uz određivanje razine kortizola u krvi. Eksperimentalni dio istraživanja proveden je kontinuiranim mjerenjem elektrokardiografskih (EKG) parametara pilota tijekom upravljanja zrakoplovom, radi izlučivanja parametara varijabilnosti srčanog ritma (hearth rate variability – HRV) u varijablama: SDNN (standardna devijacija između nn intervala), RMSSD (korijenska razlika srednjeg kvadrata uzastopnih RR intervala), pNN50% (postotak sukcesivnih nn intervala koji
se razlikuju više od 50 ms) i LF/HF (odnos niske i visoke frekvencije spektralne komponente HRV). SCORE index kardiovaskularnog rizika izračunao se iz dobivenih čimbenika rizika KVB. Gubitak sluha izmjeren je tonalnom audiometrijom obostrano na frekvencijama: 250 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz i 8 kHz
Dobiveni podatci pokazali su visoku izloženost vojnih pilota čimbenicima rizika KVB iskazanih povišenim vrijednostima: LDL kolesterola (91,6%), opsega struka 70,8%, ukupnog kolesterola (77%) i sniženoj varijabilnosti srčanog ritma (HRV) u varijablama: SDNN (83%), pNN50% (60,4%) i omjeru LF/HF (58,3%). Povišeni indeks tjelesne mase (ITM) prisutan je kod većine vojnih pilota (68,8%), dok udio pušača predstavlja trećinu ispitanika (33%). Kod trećine ispitanika rezultati ukazuju na rizike razvoja KVB temeljem pokazatelja upale CRP-HS. Dobivene razine psihičkog stresa su niske, što je potvrđeno niskim razinama kortizola. Usporedba izloženosti čimbenicima rizika KVB u istraživanju, s ranije provedenim istraživanjima na vojnim pilotima pokazuju da nema tendencije promjene stanja.
Statistička obrada povezanosti varijabli tjelesne spremnosti i čimbenika rizika KVB pokazala je povezanost slabijih rezultata tjelesne spremnosti s većom ekspozicijom rizičnih čimbenika, Tako su rezultati vremena trčanja na 2400 metara povezani s razinama: mokraćne kiseline, opsega struka, visine sistoličkog tlaka, indeksa tjelesne mase - ITM i SCORE indeksa, dok je broj pregiba trupa povezan s razinom odnosa ukupnog/HDL kolesterola i pokazateljem upale izraženim CRP-HS i SCORE indeksa. Kardiorespiratorna sposobnost (KRS) je značajno povezana s visinom sistoličkog tlaka, odnosom ukupnog/HDL kolesterola i varijablama HRV: SDNN i LF/HF. Broj učinjenih sklekova je povezan samo s kombiniranim pokazateljem kardiovaskularnog rizika SCORE
Gubitak sluha prikazan je na tri načina: po Fowler-Sabine, gubitcima na mjerenim frekvencijama i obostranom modelu po Pelausi. Gubitak sluha po Fowler-Sabineu nije pokazao povezanost s varijablama čimbenika rizika kardiovaskularnih bolesti i tjelesne spremnosti. Postoji povezanost slabijih rezultata procjene tjelesne spremnosti i većeg gubitka sluha. Tako su varijable vremena potrebnog za trčanje 2400 metara i broja pregiba trupa povezani s gubitcima sluha lijevo u prikazima po frekvencijama i po Pelausi.
Prikazane su povezanosti tjelesne spremnosti i čimbenika rizika KVB na gubitke sluha po frekvencijama na pojedinom uhu, te se dao prilog teoriji većoj vulnerabilnosti lijevog uha i konačnim učincima čimbenika rizika na ukupno slušanje.
Postoji povezanost većeg gubitka sluha u prikazu po frekvencijama s većom ekspozicijom čimbenika rizika KVB. Postoji povezanost s razinom triglicerida na desnoj strani, dok na lijevoj strani postoje povezanosti s odnosom ukupnog/HDL kolesterola, glukoze u krvi (GUK) i
pokazateljima upale (CRP-HS, mokraćna kiselina). Vidljiva je povezanost s više čimbenika rizika KVB lijevo, koji zahvaćaju govorno područje što više oštećuje slušanje. Veći gubitak sluha po Pelausi povezan je s višim razinama kardiovaskularnih rizika: ITM, opsegu struka, opsegu bokova, razine GUK, triglicerida, odnosa ukupnog/HDL kolesterola, pulsa u mirovanju i SCORE indeksa. Nema povezanosti oštećenja sluha s varijablama HRV i psihičkim stresom.
Istraživanje je pokazalo dobar odabir testova procjene tjelesne sposobnosti, koji pokazuju visoku izloženost rizicima KVB u vojnih pilota, na što je moguće preventivno djelovati stimulacijom tjelovježbe, nepušenja i promjenom prehrambenih navika. Povezanost razine čimbenika rizika KVB s rezultatima tjelesne spremnosti ukazuju na potrebu dodatnih preventivnih pregleda u cilju rane dijagnostike KVB, kod vojnih pilota srednje dobi s nižim rezultatima tjelesne sposobnosti i to posebno u varijabli sniženog broja pregiba trupa i produženog vremena trčanja za 2400 metara.
Rezultati istraživanja pokazuju da primjena preventivnih mjera, odnosno djelotvorno snižavanje rizika KVB, uz pravilnu primjenu mjera zaštite od buke, zajednički istovremeno djeluje na prevenciju KVB i zaštitu sluha u vojnih pilota.
Navedene prijedloge je potrebno implementirati u buduće pravilnike s ciljem produženja radnog i životnog vijeka vojnog pilota, a time i bojeve spremnosti. |
| Abstract (english) | Military pilots are a specific segment of the population of military personnel who are exposed to high physical exertion, stress and noise while performing flight tasks, which requires appropriate mental and physical fitness. Previous research has shown the high exposure of the aviation population to risk factors for cardiovascular disease (CVD) and hearing loss which, along with diseases of the locomotor system, represent the greatest health risks. The aim of the research is to determine the connection between the level of physical fitness and risk factors for CVD and hearing loss in a sample of military pilots, so that preventive programs for health preservation can be planned.
The research identified cardiovascular disease risc factors (CVD), assessed the state of physical fitness, measured elements of heart rate variability (HRV) during flight, and determined hearing loss in a selected sample of military pilots.
The level of physical fitness was determined by treadmill ergometry for the cardiorespiratory fitness variable (CRF), the number of push-ups and sit-ups in two minutes were tested, the time requireded to run 2400 meters was measured and the total number of points was calculated.
The examined sample consists of 48 male pilots aged 35-50 years, for whom flying is a basic, i.e. everyday activity on a multi-purpose helicopter (Mi-117Sh), training aircraft (PC-9), firefighting aircraft (Cl-415) and supersonic fighter aircraft (Mig-21).
Observed variables of CVD risk factors include: anamnestic parameters (age, smoking, number of flight hours, data on CVD heredity), clinical examination, measurements and calculations of body mass index (BMI), waist circumference, hip circumference, ratio of waist and hip circumference (waist-to-hip ratio - WHR), hearth rate at resting, systolic and diastolic blood pressure), as well as laboratory blood indicators (glucose, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, highly sensitive C-reactive protein (CRP-HS and uric acid). Psychological stress levels were obtained by testing of the acute and chronic components (STAI X1 and X2), along with the determining the cortisol level in the blood. The experimental part of the research was carried by continuous measurement of the pilots' ECG parameters during flight in order to extract heart rate variability (HRV) parameters in variables: SDNN
(standard deviation between nn intervals), RMSSD (root mean square difference of successive RR intervals), pNN50% (percentage of successive nn intervals that differ by more than 50 ms) and LF/HF (low and high frequency ratio of the spectral component of HRV). Hearing loss was measured bilaterally by tone audiometry at frequencies: 250 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz and 8 kHz.
The obtained data showed a high exposure of military pilots to CVD risk factors expressed by elevated values: LDL cholesterol (91.6%), waist circumference 70.8%, total cholesterol (77%) and reduced heart rate variability (HRV) in the variables: SDNN ( 83%), pNN50% (60.4%) and LF/HF ratio (58.3%). An elevated body mass index (BMI) is present in the majority of military pilots (68.8%), while the proportion of smokers represents a third of the respondents (33%). In a third of the subjects, the results indicate the risks of developing CVD based on the inflammation indicator CRP-HS. The obtained levels of psychological stress are low, which is confirmed by low cortisol levels. A comparison of the exposure to CVD risk factors in the research, with previously conducted research on military pilots shows that there is no tendency to change the condition.
Statistical analysis of the connection between physical fitness variables and CVD risk factors indicated the association of weaker physical fitness results with greater exposure to risk factors.
Thus, the results of running time at 2400 meters are related to the levels of: uric acid, waist circumference, systolic pressure level, body mass index - BMI and SCORE index, while the number of sit-ups is associated with the level of the ratio total/HDL cholesterol and the indicator of inflammation expressed by the level of CRP-HS. Cardiorespiratory fitness (CRF) is significantly associated with the systolic blood pressure, total/HDL cholesterol ratio and HRV variables: SDNN and LF/HF. The number of push-ups performed was only associated with the combined cardiovascular risk score SCORE
Hearing loss is presented in three ways: according to Fowler-Sabine, losses at measured frequencies and according to Pelausa model. Hearing loss according to Fowler-Sabine did not show an association with cardiovascular disease risk factor variables and physical fitness. There is an apparent association between weaker results of the assessment of physical fitness and greater hearing loss, thus the variables of the time required to run 2400 meters and the number of sit-ups are associated with hearing loss on the left side in the representations by frequencies and according to Pelausa.
The correlations between physical fitness and CVD risk factors on hearing loss at frequencies in each ear are presented, and a contribution is made to the theory of greater vulnerability of the left ear and the final effects of risk factors on overall hearing.
There is an association of greater hearing loss in frequency display with greater expression by reducing CVD risk factors. Thus, there is an association with the level of triglycerides on the right side, while on the left side there are associations with the ratio of total/HDL cholesterol, blood glucose (GUC) and indicators of inflammation (CRP-HS, uric acid). There is an apparent association with several left CVD risk factors, which are associated with hearing loss in the speech area, which damages the hearing more. Greater hearing loss according to Pelausa is associated with higher levels of cardiovascular risks: BMI, waist circumference, hip circumference, GUK levels, triglycerides, total/HDL cholesterol ratio, resting heart rate and SCORE index. There is no connection between hearing loss and HRV variables and psychological stress.
The research showed a good selection of physical fitness assessment tests, which indicate a high exposure to CVD risks in military pilots which can be prevented by stimulating exercise, not smoking and changing dietary habits. The high correlation of the level of CVD risk factors with the results of physical fitness indicates the need for additional preventive examinations aimed at early diagnosis of CVD, in middle-aged military pilots with lower results of physical fitness, especially in the variable of a reduced number of sit ups and prolonged time running on 2400 meters.
The results of the research show that the application of preventive measures, i.e. the effective reduction of the risk of CVD along with the proper application of measures to protect against noise, simultaneously works on the prevention of CVD and the protection of hearing in military pilots.
The aforementioned proposals should be implemented in future regulations in order to extend the working and life span of military pilots and thereby combat readiness. |
