RU2740532C1 - Method for predicting risk of stroke in men working in environment of industrial noise exposure on position of pilot of civil aircraft - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention refers to medicine and enables predicting a risk of developing a stroke in male patients aged 42 to 57 years, working for 15 years and more under conditions of industrial noise and other harmful occupational factors on the position of Pilot of Civil Aircraft. Level of total cholesterol, the presence or absence of atrial fibrillation, the presence or absence of the alcohol abuse factor, the diagnosis of grade 2 AH or grade 3 AH. Values of the above parameters are substituted into the original design formula and the probability of developing the stroke in the examined p(X) is calculated. P(X) value greater than 0.5 indicates a high risk of stroke in the patient.EFFECT: method enables predicting the risk of stroke in male patients aged 42 to 57 years, who have been working for 15 years and more in conditions of industrial noise and other harmful occupational factors on the position of Pilot of Civil Aircraft.1 cl, 7 tbl, 4 ex

Description

The invention relates to occupational medicine.

Depending on the type of activity and specific flight conditions, the body of aircraft crew members is adversely affected by a whole range of harmful, dangerous, stressful, difficult working conditions. Industrial noise has a significant negative effect on the body, in particular on the cardiovascular system.

There are no reliable means of protection against aircraft noise, and the need for constant radio exchange only enhances its effect on the body of crew members.

Manifestations of noise impact on the human body can be conditionally subdivided into specific changes occurring in the organ of hearing, and nonspecific, occurring in other organs and systems.

In response to prolonged exposure to noise, the nonspecific hypothalamic-pituitary-adrenal system is involved with an accelerated and increased release of serotonin, kallikrein into the blood, their impact on smooth muscle cells of the walls of blood vessels (with the exception of veins or capillaries), which leads to their contraction, increased tone blood vessels (later - to atony), tissue and organ ischemia, hypoxia, acidosis, and later - to destructive changes in organs with genotypically and ontogenetically determined hypersensitivity (Ereniyev S.I., Plotnikova O.V. et al. , 2013).

Noise is the second (after psychogenic) factor in importance, contributing to the occurrence of arterial hypertension (AH) (Vermel A.E., 1995; Monaenkova A.M., 1996).

The participation of the cardiovascular system in the pathological process that develops under the influence of noise is manifested by lability of the pulse, increased vascular tone of the muscular type, fluctuations in blood pressure with a tendency to hypertension, with severe forms of the disease - the development of chronic ischemic heart disease (Kholopkina N.A., 2016). So, when examining male flight personnel, coronary heart disease (IHD), as a concomitant pathology, was revealed in 25% of cases, in 8% of cases, cardiovascular pathology was complicated by an acute myocardial infarction, and in most cases (84%) IHD was combined with hypertensive disease.

When distributed according to the degree of hearing loss, a significant degree of hearing loss was diagnosed in 56% of cases, of which IHD was recorded in 53%. The diagnosis of a moderate degree of hearing loss was established in 28% of cases, coronary artery disease - in 32% of the examined. The proportion of mild hearing loss was 16%, of which CHD was detected in 25% of cases. In the flight crew, in the structure of concomitant pathology, IHD takes the second place after arterial hypertension, its prevalence increased in proportion to the increase in the degree of hearing loss (Kholopkina N.A., 2016).

In addition to noise, harmful labor factors for the crew members of civil aviation include: increased vibration levels; fluctuations in atmospheric pressure during takeoffs, landings, climb and descent; reduced partial pressure of oxygen in the cabins (hypoxia); thermal discomfort in the cabins; unsatisfactory physical and chemical composition of the inhaled air; increased radiation (background) exposure; increased electromagnetic fields; turbulence in the air; Microwave radiation from ground and airborne equipment.

When studying the prior art, no sources were found describing methods of the same purpose as the proposed method.

In the following known methods for predicting the development of stroke or arterial hypertension, any of the parameters taken into account in the proposed method appear: occupational noise, alcohol abuse, age or male gender of patients.

1. According to the method for assessing the occupational health risk associated with the development of arterial hypertension in workers engaged in underground mining in working conditions with industrial noise at a level above the permissible level (RF patent No. 2639130), the following indicators are determined in workers: the content of high density lipoproteins , homocysteine, atherogenic index, malondialdehyde level, antioxidant activity level, vascular endothelial state. In case of confirmation for all the indicated laboratory parameters of their professional conditionality, the probability of a deviation from the norm in the state of the vascular endothelium in workers and the likelihood of developing arterial hypertension in workers with deviations from the norm in the state of the vascular endothelium are determined. As a result, the occupational health risk of employees is calculated.

This method allows you to determine the occupational health risk of workers exposed to industrial noise. However, this risk is associated with the development of hypertension, not stroke.

2. The known "Method for predicting the risk of ischemic stroke" by RF patent No. 2685859. In representatives of the Russian nationality, who are residents of the Central Black Earth Region, the combination of the AA rs909253 Ltα genotype with the GG rs 1800629 TNFα genotype and alcohol abuse is a risk factor for the development of ischemic stroke.

3. Invention according to RF patent No. 2648532 "A method for predicting the risk of acute ischemic stroke in patients under 50 years of age with newly diagnosed arterial hypertension" allows predicting the risk of stroke in patients of a certain age group.

4. The invention under the patent of the Russian Federation No. 2664430 "Method for predicting the risk of stroke in men on the basis of genetic testing" takes into account the gender factor.

None of the above methods were developed in the professional group of "civil aviation pilots".

Disclosure of the essence of the invention

The proposed method for predicting the risk of developing a stroke in a patient is characterized by the fact that the patient is a man aged 42 to 57 years, who has been working for 15 years or more under conditions of exposure to industrial noise and other harmful production factors by the profession of "civil aviation pilot" the following parameters: the concentration (level) of total cholesterol in the blood serum, the presence or absence of arterial hypertension (AH) 2 degrees, AH 3 degrees, atrial fibrillation, alcohol abuse factor in the patient, the values of the above parameters are substituted in the formula below in the following form:

- the concentration of total cholesterol in serum (X1) is indicated in mmol / l;

- the presence or absence of atrial fibrillation (X2) in the patient is taken into account as follows: in the presence of fibrillation, X2 takes the value "1", in the absence - "0";

- the presence or absence of alcohol abuse factor (X3) in the patient's history is taken into account as follows: in the presence of factor X3, it takes the value "1", in the absence - "0";

- if the patient has grade 2 hypertension, X4 takes on the value "1", in the absence - "0";

- if the patient has grade 3 hypertension, X5 takes the value "1", in the absence - "0",

calculate the likelihood of developing a stroke in the examined patient using the formula:

where z (X) = 1.0X1 + 2.9X2 + 1.1X3 + 1.3X4 + 1.8X5 - 6.9, (why 1?)

and when the p (X) value exceeds 0.5, it is concluded that the patient is at high risk of developing a stroke.

Technical results of the proposed method:

- the proposed method makes it possible to predict the risk of stroke in a male patient aged 42 to 57 years, who has been working for 15 years or more as a civil aviation pilot under the influence of industrial noise and other negative industrial factors;

- the sensitivity of the proposed method was 72.7%, the specificity was 73.6%.

Justification of the method

Were examined two groups of men - pilots of civil aviation at the age from 42 to 57 years.

The first group of examined men consisted of 44 men hospitalized in the neurological department of the Novosibirsk City Clinical Hospital No. 1 with a diagnosis of stroke, who had worked for 15 years or more in this profession under conditions of exposure to industrial noise and other factors mentioned above, namely: an increased level vibration; fluctuations in atmospheric pressure; hypoxia; temperature discomfort in the cabins; unsatisfactory physical and chemical composition of the inhaled air; increased radiation (background) exposure; increased electromagnetic fields; Microwave radiation from ground and airborne equipment.

The stroke diagnosis was made in accordance with the 10th revision of the International Classification of Diseases.

The second group consisted of 53 men who had no history of stroke and who underwent examination and treatment in the clinic for occupational diseases of the Novosibirsk Research Institute of Hygiene of the Federal Service for Surveillance on Consumer Rights Protection and Human Welfare. The persons included in the second group worked under the same conditions as the persons from the first group, for 16 years or more.

The average age of patients in the first group was 49.1 years (m = ± 1.4, δ = ± 7.5). The average work experience in the above profession at the time of stroke development was 26.5 years (m = ± 0.7, δ = ± 4.8).

The average age of patients in the second group was 51.6 years (m = ± 1.3, δ = ± 5.4). The average work experience in the above profession is 29.7 years (m = ± 1.7, δ = ± 6.8).

Thus, the studied groups were comparable in terms of age and experience.

Statistical analysis was performed using the SPSS11.5 software package. The Kolmogorov - Smirnov test was used to check the normal distribution of features. Fisher's test was used to analyze qualitative features. To determine the reliability of differences between independent samples with a normal distribution law, Student's t-test was used for independent observations. Data were presented in the form of "arithmetic mean" (M), its error (m ±), standard deviation (σ ±). The critical level of significance when testing statistical hypotheses in the study was taken equal to 0.05.

In patients of the first and second groups, the following indicators were determined: age; work experience as a civil aviation pilot; presence of hypertension, degree of hypertension; control by the patient of his blood pressure; taking antihypertensive drugs by the patient; a history of ischemic heart disease, atrial fibrillation, dyslipidemia, diabetes mellitus, smoking and alcohol abuse factors; total cholesterol level.

The diagnosis of hypertension and its degree included the following stages: clarifying the patient's complaints, taking anamnesis, repeated measurements of blood pressure, physical examination, instrumental research methods. Elucidation of complaints and collection of anamnesis were carried out to assess family predisposition to hypertension and cardiovascular diseases; determining whether or not the patient is taking antihypertensive drugs.

Physical examination included measurement of waist circumference, cardiac auscultation, and palpation of peripheral arteries.

Instrumental research methods included:

- ECG recording, which was carried out according to the generally accepted method on a 12-channel electrocardiograph. Based on the determination of the Sokolov-Lyon index, the presence or absence of left ventricular hypertrophy was established;

- ECHO-KG to clarify the presence and severity of LVH, diastolic dysfunction, dilatation of the left atrium and other heart lesions;

- examination of the fundus in order to exclude hemorrhages, exudates, edema of the papilla of the optic nerve.

The presence of myocardial infarction in the anamnesis was confirmed by the corresponding medical documents (outpatient cards, discharge epicrisis) and ECHO-KG.

The presence of atrial fibrillation was established using an ECG, Holter ECG monitoring, or in the presence of records in medical documents (outpatient records, discharge epicrisis).

Glucose studies were performed at the time of hospitalization by the glucose oxidase photometric method at the endpoint using a specialized biochemical photometer of the Mikrolab 540 type (Russia). A One Tonch glucometer (USA) was used to quickly measure the blood glucose level. The diagnosis of diabetes mellitus (type, severity, stage of compensation), the presence of angiopathies was established in the presence of appropriate clinical and paraclinical data with the participation of an endocrinologist.

The study of the level of total cholesterol in hospitalized patients was carried out by the enzymatic method (by oxidation of cholesterol by cholesterol oxidase). The study of the level of low-density lipoproteins, high-density lipoproteins, triglycerides was carried out by the enzymatic colorimetric direct method on a biochemical analyzer "AU 480" from "Bechman Coulter" (USA).

Hypercholesterolemia was diagnosed with a total cholesterol (CS) level of more than 6.5 mmol / L, hyperlipoproteinemia - with a low density lipoprotein level of more than 50 a.u.

The presence of a smoking factor was recognized in persons who smoked at least one cigarette (cigarette) per day for at least the last three months before the development of stroke in patients of the first group and until the moment of examination in patients of the second group (Oleinikov S.P., Glazunov I. .S., Chazova L.V., 1981).

Alcohol abuse was established in the case of its systematic intake (at least once every 7 days) in the amount of at least 200 grams in terms of ethyl alcohol per week, despite recurrent negative consequences, as well as in the presence of information from medical records (observation by a narcologist, diagnosis of alcoholic epilepsy, chronic alcoholism) (Agibalova T.V., Shustov D.I. et al., 2015). The DSM-IV (Diagnostic Standard in Psychiatry and Physiology) defines alcohol abuse as repeated use despite recurrent adverse effects (Gary R. Vanden Bos, 2007).

Development of a mathematical model for predicting the risk of stroke in men working under conditions of exposure to industrial noise and other negative industrial factors as a civil aviation pilot

To determine the reliability of the differences in the features, the analysis of contingency tables was used (Pearson's χ2 test, as well as the two-sided Fisher's exact test if the expected value in at least one cell of the contingency table was less than 5). We used binary logistic regression to build a prognostic model for identifying significant indicators that make a significant contribution to the development of stroke in patients of the studied professional group.

The relative risk (RR) of stroke and its 95% confidence interval (CI) were calculated.

When constructing a logistic regression model, the Forward Stepwise method was used. With its help, the indicators were selected that make the greatest contribution to the development of stroke in men of the studied professional group (Table 1).

They were the level of total cholesterol, the presence or absence of atrial fibrillation in the patient, alcohol abuse factor, AH grade 2 or AH grade 3.

Based on the analysis, the following logistic regression formula was derived, which determines the likelihood of developing a stroke in a man aged 42 to 57 who has been working for 15 years or more in the profession of "civil aviation pilot":

where z (X) = 1.0X1 + 2.9X2 + 1.1X3 + 1.3X4 + 1.8X5-6.9 (constant),

- the level of total cholesterol in the serum (X1) is indicated in mmol / l);

- the presence or absence of atrial fibrillation (X2), alcohol abuse factor (X3), AH grade 2 (X4), AH grade 3 (X5) is taken into account as follows: in the presence of an appropriate factor (atrial fibrillation, alcohol abuse, diagnosis 2 degrees "or" AG 3 degrees ") X2, X3, X4, X5 take the value" 1 ", in the absence -" 0 ".

The calculation of the p (X) value can be implemented in an Excel spreadsheet processor.

Below are tables 2 and 3, which show the calculated p (X) values for patients of the first and second groups, respectively.

A p (X) value exceeding 0.5 indicates a high risk of stroke in a man aged 42 to 57 who has worked for 15 years or more as a civil aviation pilot.

This cut-off point gives the optimum balance of sensitivity and specificity. The sensitivity of the proposed method was 72.7%, specificity was 73.6%.

Examples of implementation of the proposed method

1. Patient B., 45 years old. He worked as a pilot on an IL-96 aircraft for 22 years. He was admitted to the neurological department with a diagnosis of hemorrhagic stroke. History - increased blood pressure within 6 years to 160/110 mm Hg. Blood pressure at the time of the development of a stroke is 240/120 mm Hg. Was examined by a cardiologist. On the basis of examination and examination, the diagnosis was made - "hypertension 3 tbsp., AH 3 tbsp., Risk 4". Atrial fibrillation and alcohol abuse factor are absent. The total cholesterol level in the blood is 6.5 mmol / l.

The obtained value of P (X) exceeds 0.5, which indicates a high risk of stroke in the patient from example No. 1 (Table 4). The result obtained coincides with the real situation - the development of a stroke in this patient.

2. Patient I., 38 years old. He worked as a pilot on the An-148 type civil aviation aircraft for 16 years. Was admitted to the neurological department with a diagnosis of ischemic stroke. BP at the time of the onset of stroke was 180/100 mm Hg. Was examined by a cardiologist. On the basis of examination and examination, the diagnosis was made - "hypertension 3 tbsp., AH 3 tbsp., Risk 4". Atrial fibrillation was not detected, alcohol abuse factor was absent. The total blood cholesterol index is 5.6 mmol / l.

The obtained value of P (X) exceeds 0.5, which indicates a high risk of stroke in the patient from example No. 2 (Table 5), confirmed by a real stroke.

3. Patient K., 47 years old. The total length of service as a pilot is 26 years. He is currently working as a pilot of a Boeing-747 aircraft. Was being treated at the clinic of occupational diseases of the Novosibirsk Research Institute of Hygiene. The patient had no history of stroke. Increase in blood pressure within 4 years to 160/110 mm Hg. At the time of examination, the pressure was 150/100 mHg. The patient monitors blood pressure and regularly takes antihypertensive drugs. Was examined by a cardiologist. On the basis of examination and examination, the diagnosis was made: hypertension, grade 3, hypertension grade 3, risk 3. Atrial fibrillation was not detected, alcohol abuse factor was absent. The indicator of total cholesterol in the blood is 4.73 mmol / l.

The P (X) value turned out to be less than 0.5, which indicates a low risk of stroke in the patient from example No. 3 (Table 6). The prognosis was confirmed by the absence of a stroke in the patient.

4. Patient K., 53 years old. The total work experience as a pilot is 28 years. He is currently working as a pilot of the Embraer-170 aircraft. Was being treated at the clinic of occupational diseases of the Novosibirsk Research Institute of Hygiene. The patient had no history of stroke. Increase in blood pressure within 5 years to 140/00 mm Hg. At the time of examination, blood pressure is 110/80 mm Hg. The patient monitors blood pressure and regularly takes antihypertensive drugs. Was examined by a cardiologist. As a result of the examination and examination, the diagnosis was made: "hypertension 1 tbsp., AT 1 tbsp., Risk 2". The patient has no atrial fibrillation, no alcohol abuse. The total blood cholesterol index is 5.02 mmol / l.

The P (X) value is less than 0.5, which indicates a low risk of stroke in the patient from example No. 4 (Table 7). The prognosis is confirmed by the absence of a stroke in the patient.

Bibliography.

1. Agibalova T.V., Shustov D.I., Tuchina O.D., Mukhin A.A. The strategy of reducing alcohol consumption as a new opportunity in the treatment of alcohol dependence // Social and Clinical Psychiatry. - 2015. - T. 25. - No. 3. - S. 61-68.

2. Vermel A.E., Zenenko G.N., Kochanova E.M. Intense industrial noise and the incidence of arterial hypertension // Therapeutic archive. - 1995. - No. 9. - S. 88-91.

3. Ereniyev S.I., Plotnikova O.V., Demchenko V.G., Glotov A.V. and others. Occupational diseases from exposure to industrial noise / Methodical recommendations. - Omsk: Publishing house. - 2013 .-- 42 p.

4. Monaenkova A.M. The influence of unfavorable occupational factors on the cardiovascular system // Occupational diseases / Ed. N.F. Izmerova. - Moscow, 1996 .-- T. 2. - S. 404-425.

5. Oleinikov S.P., Glazunov I.S., Chazova L.V. Smoking among men and women of different age groups // Therapeutic archive. 1981 - # 2. - S. 5-28.

6. Kholopkina N.A. Features of ischemic heart disease in patients with professional sensorineural hearing loss // Materials of the All-Russian scientific-practical conference with international participation. - Mines, 2016 - S. 225-227.

7. Gary R. Van den Bos. APA Dictionary of Psychology, 1st ed., Washington: American Psychological Association, 2007.

Claims (10)

A method for predicting the risk of developing a stroke in a patient, including his examination, characterized in that the patient is a man aged 42 to 57 years, who has been working for 15 years or more as a civil aviation pilot, the following parameters are determined: total cholesterol concentration in blood serum, the presence or absence of arterial hypertension (AH) 2 degrees, AH 3 degrees, atrial fibrillation, alcohol abuse factor in a patient, the values of the above parameters are substituted into the formula below in the following form: - the concentration of total cholesterol in serum (X1) is indicated in mmol / l; - the presence or absence of atrial fibrillation (X2) in the patient is taken into account as follows: if it is present, X2 takes the value "1", in the absence - "0"; - if the patient has a history of alcohol abuse factor X3 takes the value "1", in the absence - "0"; - if the patient has grade 2 hypertension, X4 takes on the value "1", in the absence - "0"; - if the patient has grade 3 hypertension, X5 takes the value "1", in the absence - "0"; calculate the likelihood of developing a stroke in the examined patient using the formula

where z (X) = 1.0X1 + 2.9X2 + 1.1X3 + 1.3X4 + 1.8X5-6.9, a p (X) value exceeding 0.5 indicates a high risk of stroke in the patient.