Peculiarities of the Epidemiology and Secondary Prevention of Diabetes Mellitus among Motor Vehicle Drivers, and Road Traffic Safety

The dissertation is devoted to the study of the epidemiology of diabetes mellitus and atherosclerosis risk factors among professional motor vehicle drivers, as well as to the development of approaches to the secondary prevention of these disorders with account taken of the conditions of their working activity. The work is based on comparative epidemiological surveys of drivers and persons of non-driving professions, on clinical-functional and psychological examination of drivers with diabetes mellitus and arterial hypertension, and on an assessment of the effectiveness of drug and non-drug therapy. Particular attention is paid to the influence of the disease on professionally significant functions, the system of operative response and road traffic safety. The data obtained were used to develop a comprehensive programme of medico-psychological monitoring and to substantiate the necessity of revising medical contraindications to the management of vehicles in the combination of diabetes mellitus with arterial hypertension.

The state of health of the working population is the most important indicator of the well-being of society, determining the quality of labour resources and the demographic situation in the country, labour productivity, and the gross domestic product (GDP). An analysis of health indicators of the working population of the Russian Federation (totalling 66.8 million people, including 33.9 million women) testifies to its significant deterioration: in recent years, a substantial rise in morbidity among persons of working age has been recorded due to pathology of the cardiovascular, gastrointestinal, neuroendocrine systems, and the musculoskeletal apparatus (Izmerov N.F., 2007). Mortality among working-age Russians exceeds the analogous indicator for the European Union by a factor of 4.5 and that for the entire population of the country by a factor of 2.5. Each year the number of deaths exceeds that of births by almost one million. The principal causes of low life expectancy in the Russian Federation are the extremely high mortality of the working-age population and a considerable share of mortality from external causes (alcohol poisonings, suicides, homicides, transport and other injuries). Unfortunately, in modern Russia the level of road accidents has shown a tendency toward a marked increase. In 2006–2008, 32–34 thousand Russians perished in road traffic accidents in the country, while the frequency of transport accidents and the number of victims and injured persons increased. According to World Bank data, in 2003 cardiovascular diseases, malignant neoplasms and injuries caused 78% of deaths in Russia and the loss of 15.2 million years of potential life of people of working age. The proportion of those working in conditions that do not meet sanitary and hygienic norms amounted to 20.8% of the total number of workers (Rosstat data, 2006). At present, 20 to 40% of labour losses are caused by diseases directly or indirectly associated with unsatisfactory working conditions. On average, 10 working days per worker are lost owing to illness, which amounts annually to losses of about 1.4% of GDP. More than 20% of all persons first recognised as disabled lost their working capacity at the age of 45–50 years. Occupational risks significantly worsen mortality indicators from chronic non-communicable diseases (by 15% from asthma, 13% from chronic obstructive pulmonary diseases, 13% from cardiovascular pathology, 10% from oncological diseases and 8% from injuries). For this very reason, only the creation of a national system of occupational medicine, including for hazardous professions, adapted to international requirements and standards, is capable of ensuring favourable conditions for the protection of the health of the country's working population (Izmerov N.F., 2007; Elgarov A.A. et al., 2007). Among the most widespread chronic non-communicable diseases (CNCDs) representing a serious threat to the health of the population of the majority of countries in the world, diabetes mellitus (DM) has occupied a special place in recent decades (Dedov I.I., 1998; Dedov I.I. et al., 1998, 2004, 2006; Balabolkin M.I., 2000; King H., Aubert R., Herman W., 1991; Grundy S.M., Benjamin I.J., Burke G.L. et al., 1999; Gan S.K., Chisholm D.J., 2001; Deedwania P.C., 2003; Balkau B., 2005). This pathology is a top-priority problem facing medical science and public health practically in all countries of the world. Modern diabetology, unlike any other discipline, is developing with exceptional dynamism. The molecular-genetic, immunological, hormonal-metabolic aspects of the aetiology and pathogenesis of DM are being intensively studied in the leading laboratories of the world. The newest technologies of the fundamental and applied natural sciences are being promptly introduced into the diagnosis, treatment and prevention of diabetes. At the same time, the present pandemic of DM is recognised, affecting 246 million people of those living on the planet (Global prevalence of diabetes, 2006), and in our country 28 million (Dedov I.I., Fadeyev V.V., 1998). Over the past 30 years a sharp rise in morbidity has been noted, especially in economically developed countries. Every 10–15 years the number of patients with DM doubles. According to WHO forecasts, by 2025 it will reach 380 million, with 80–90% of patients having type 2 DM (Global prevalence of diabetes, 2006). The estimated growth in morbidity for the period from 1995 to 2030 amounts to 60%, although in some countries the growth rates already significantly exceed those predicted (Lipscombe L., 2007). DM is accompanied by early disability and high mortality of the population, accounting for approximately 3.8 million deaths annually (Global prevalence of diabetes, 2006). In the United States DM ranks sixth among the principal causes of death in the population, and the economic expenditures it entails amount to about 100 billion dollars per year, or 13% of all healthcare expenditures (American Diabetes Association, 1998). Type 2 DM is the principal and independent risk factor for the development of cardiovascular diseases and the mortality associated with them (Stamler J. et al., 1993). At present, in countries that have achieved significant success in combating coronary heart disease, patients with DM constitute the only population group in which mortality from cardiovascular diseases is decreasing slightly among men and increasing among women (Dedov I.I., Shestakova M.V., 2002). The presence of type 2 DM is associated with an increased risk of all forms of coronary heart disease, including stable angina, painless myocardial ischaemia, myocardial infarction, as well as sudden cardiac death (Mychka V.B. et al., 2002; Mazur N.A., 2003; Strogan L.G., Pochinka L.G., 2005; Pyorala K. et al., 1987). Arterial hypertension (AH) and chronic heart failure (CHF) are the most frequent conditions in patients with DM (Sokolov E.I., 2001; Gurevich M.A., 2005; Belousov Yu.B. et al., 2005; Konstantinov V.O., Sayfulina Ya.R., 2006). Data from the Framingham project showed an increase in the risk of CHF by a factor of 4 in men and by a factor of 8 in women in the presence of type 2 DM (Kannel W.B., McGee D.L., 1979). In this case decompensation of DM plays an important role (Georgadze Z.O. et al., 2007). The combination of these diseases not only aggravates the course of each of them, but also leads to the rapid development of atherosclerosis (AS) and vascular complications. An elevated level of triglycerides in patients with type 2 DM also accelerates the onset of AS. In DM the risk of AS is 4–5 times higher than in the population on average (Dedov I.I., Melnichenko G.A., Fadeyev V.V., 2000). This is explained, on the one hand, by disorders of lipid metabolism and, on the other, by morphofunctional changes in the activity of the vascular wall (Sokolov E.I., 2000; Mychka V.B. et al., 2002). The leading role of early cardiovascular mortality in limiting life expectancy in the overwhelming majority of patients with type 2 DM allowed the American Heart Association to classify DM as a cardiovascular disease (Grundy S.M. et al., 1999). This is due both to the wide spread of the disease, which leads to disability and high lethality, the difficulties of early detection, treatment and determination of prognosis, and to the frequency of the principal risk factors for diabetes. Along with this, the most important and topical applied task is the achievement of compensation in the state of health of persons with DM, first and foremost of the working population, and the preservation of the quality of professional activity of a special group — persons of operator professions (vehicle drivers, pilots, dispatchers, etc.). Diabetes and the management of motor vehicles represent a very important problem in modern society. The deterioration of the quality of professional activity of motor vehicle drivers in the presence of DM, which is frequently combined with AH, is accompanied by an increase in cardiovascular risk and the development of various complications (hypo-, hyperglycaemia, retinopathy), which imparts a social character to this problem in connection with the increasing number of road traffic accidents with all their consequences (Cox D.J. et al., 1994, 2001, 2003, 2006, 2007; Kovatchev B. et al., 2003; Hansotia P., Broste S.K., 1991; Adams K.M., 2003). If one takes into account the peculiarities of the working activity of drivers (constant psychoemotional overstrain), then the probability of the onset or progression of this disease is significantly higher than in groups of other professions. Although in recent years the questions of the epidemiology of DM have attracted the attention not only of endocrinologists, but also of cardiologists, nephrologists, and therapists, no special studies of the frequency of DM and atherosclerosis risk factors among motor vehicle drivers and other persons of operator professions have been found by us in the special literature. And, finally, the particular significance of the implementation of a complex of medico-psychological monitoring of drivers in general and those with DM in particular for ensuring the safe management of motor vehicles and the prevention of the development of particularly significant cardiovascular diseases and DM in healthy persons, and adequate secondary prevention of AH and DM, undoubtedly has not only medical but also social significance. Precisely for this reason, the prevention and adequate treatment of DM in general and, among the working population in particular, belongs to the most topical problems of modern public health. Early diagnosis of DM and cardiovascular risk factors at the preclinical stage, and medico-psychological control among persons of operator professions will provide real conditions for the strengthening of their health, the reduction of expenditures on the treatment of manifest diseases and their complications, and the preservation of occupational longevity. An analysis of the results of epidemiological surveys, data of preventive medical examinations and clinical observations shows that in recent years in the Russian Federation, contrary to the preceding decrease in production volumes, a tendency toward an overall growth of occupational and production-conditioned pathology, disability and mortality of the working population is maintained (Izmerov N.F., 2003; Starodubov V.I., 2005). This is connected with the fact that harmful occupational factors are not only the basis for the formation of the said morbidity, but are also capable of triggering pathogenetic mechanisms of the development and progression of CNCDs, first and foremost, cardiovascular diseases and DM. That is why, at the present stage, one of the most important tasks and priority directions of occupational medicine is the identification of the pathogenetic bases of the general and specific reactions of the organism to the action of production factors, with the aim of developing and substantiating criteria and methods of objective diagnosis of premorbid states, assessment of the course of diseases, and the effectiveness of preventive and therapeutic measures being carried out (Bezrukova G.A., Spirin V.F., 2003). Comprehensive monitoring of the state of health of workers is the most important task of occupational medicine, since the conditions of production activity do not always meet normative requirements. In addition, in recent years the number of occupational groups strictly connected with systematic psychoemotional tension and overstrain has tended to increase. Possibly for this reason, against the background of a relative stabilisation of the level of occupational pathology, an increase in the prevalence of occupationally conditioned diseases (OCDs) has been observed [Krasovsky V.O., Karamova L.M., 1995; Pokrovsky V.I., 2003]. It has been shown that the character of the developing occupational diseases and OCDs and their clinical course are determined not only by the aggressiveness of harmful (unfavourable) occupational-environmental factors, but also by the individual characteristics of the organism itself (Tarasova L.A. et al., 2003). The development of the syndrome of nervous-emotional overstrain among various occupational groups causes a significant increase (up to 80.0%) in psychosomatic diseases. According to data of the State Statistics Committee of the Russian Federation, in the country 21.3% of the total number of those employed in industry, 11.2% in transport, 9.9% in construction and 2.5% in communications work under harmful conditions that do not meet sanitary and hygienic norms. Unsatisfactory working conditions remain in the majority of branches of the economy, which has conditioned a stable level of occupational morbidity, a high level of accidents, loss of working capacity, disability and mortality of workers, and the deterioration of the reproductive health of employees (Belyaev E.N. et al., 2003; Izmerov N.F., 2003). At the same time, in recent years about 230 thousand road traffic accidents have been registered annually on the country's roads, as a result of which 32–34 thousand people perish and more than 280 thousand receive injuries. The principal cause of this is the human factor, i.e. the vehicle driver. The implementation of special programmes for the protection of the health of workers in various branches of production is the most important direction of effective management of the state of health and working capacity of employees (Izmerov N.F., 2003, 2005; Pokrovsky V.I., 2003; Starodubov V.I., 2005). The urgent necessity of developing the programme "Health of Persons of Hazardous Professions" under modern conditions does not give rise to doubt (Elgarov A.A. et al., 2007). An emotionally tense, monotonous labour process usually leads to fatigue and a semiconscious state, and to changes in the function of the analysers (first of all the visual one) of workers, which naturally affects the quality of operative activity and increases the probability of erroneous decisions and actions (Goretsky O.S. et al., 1995). This is a very important risk factor for the occurrence of catastrophes — automobile-road, railway and aviation ones, the prevention of which is a topical problem of transport medicine (Vaisman A.I., 1979, 1988; Elgarov A.A., 1990; Tsfasman A.Z., 2005, 2006; Elgarov A., Aramisova R., 2001). The way of life of persons of operator professions and hazardous professions (HP) is a special, specific style, as a rule aggravated by widespread modern harmful habits (smoking, hypodynamia, obesity, alcohol consumption) and by psychoemotional stress connected with the character of work. It is evident that this circumstance affects the state of health and the rate of occurrence of diseases, the course of which progresses in connection with the way of life and the influence of production factors. The scientific literature presents diverse information on the frequency of DM (Dedov I.I., Shestakova M.V., 2003; Dedov I.I. et al., 2003, 2006; Balabolkin M.I., 2000; Waller J.A., 1965; DCCT, 1993, 1997), on the diagnosis and secondary prevention of this pathology, pointing to the urgency and topicality of the problem under discussion. At the same time, no special comparative epidemiological studies of persons of operator professions for the assessment of the level of prevalence of DM, or clinical-psychophysiological monitoring of professional drivers with this disease for the clarification of its influence on occupational performance, have been found by us in print. A study of the influence of occupational factors of motor vehicle drivers on the occurrence and course of DM, and the development of a system of effective monitoring of clinical-haemodynamic and psychological indicators in this case can ensure the necessary level of health and stable and error-free production activity of drivers in the process of managing motor vehicles. It should also be recognised that there is a necessity of revising and optimising the medical contraindications for the management of motor vehicles (orders No. 555 of the Ministry of Health of the USSR of 26.09.1989 and No. 90 of the Ministry of Health and Medical Industry of the Russian Federation of 14.03.1996) in the presence of DM and in combination with AH. In connection with the above, an extremely important task is a real assessment of the epidemiological situation with respect to DM and atherosclerosis risk factors among professional drivers taking into account the peculiarities of their production activity, as well as their possible influence on the system of operative response and the quality of professional activity. The aim of the scientific research is to study the prevalence of DM and atherosclerosis risk factors among motor vehicle drivers, to determine the occupational risk of drivers with DM and AH, the peculiarities of their secondary prevention, as well as the influence of DM in combination with AH on the professionally significant functions and qualities of the individual. Tasks: 1) to study the frequency of DM and atherosclerosis risk factors among drivers in comparison with persons of non-driving professions; 2) to determine the association of the prevalence of DM and atherosclerosis risk factors, including peculiarities of nutrition, with the conditions of activity of motor vehicle drivers; 3) to clarify the influence of DM and AH on the state of occupational working capacity; 4) to establish the effectiveness and safety of drug and non-drug therapy of motor vehicle drivers with DM and AH; 5) to develop a system of medico-psychological monitoring of motor vehicle drivers with DM and AH at motor transport enterprises. Statements submitted for defence: — the frequency of DM and coronary heart disease risk factors among motor vehicle drivers is considerable; it depends not only on age, but also on the peculiarities of working activity; — among drivers a high occupational cardiovascular risk is observed, conditioned by an aggravated way of life and a marked frequency of atherosclerosis risk factors; — DM and AH in motor vehicle drivers reduce the system of operative response, which increases the risk of the occurrence of road traffic accidents; — drug treatment of motor vehicle drivers with DM and AH must be evaluated not only with account taken of favourable changes in the general somatic status and clinical-haemodynamic indicators, but also of changes in professionally significant functions and qualities; — in solving medico-social and expert questions, including that of the occupational fitness of motor vehicle drivers with DM and AH, psychophysiological testing is obligatory. Scientific novelty. For the first time the frequency of DM and atherosclerosis risk factors among motor vehicle drivers has been studied in a comparative aspect. A reliable deterioration of professionally significant functions and qualities of motor vehicle drivers in the presence of DM and AH has been shown. The effectiveness and safety of drug and non-drug therapy of motor vehicle drivers with DM and AH have been established with account taken of their influence on the system of operative response of the individual. A comprehensive medico-psychological programme of monitoring of motor vehicle drivers with DM and AH has been developed. Practical significance. The character of the production activity of drivers determines the frequency of DM and atherosclerosis risk factors. The presence of DM and AH reliably worsens the occupational working capacity of motor vehicle drivers. In the process of treatment (drug and non-drug) of drivers with DM, as well as in resolving questions of occupational fitness for the management of a vehicle, an absolutely necessary element is the study of the dynamics of the system of operative response — the professionally significant functions and qualities of the individual — as well as of cardiohaemodynamics. It should be recognised that there is a necessity of revising and refining the official medical contraindications for the management of vehicles by persons with DM and AH. Implementation in practice. The principal propositions of the scientific research have been implemented in the practical work of the city polyclinics (No. 1 and 4), the Republican Cardiological and Endocrinological Centres of the Ministry of Health of the Kabardino-Balkarian Republic, as well as the polyclinic and inpatient department of the hospital of the Medical-Sanitary Unit of the Ministry of Internal Affairs for the Kabardino-Balkarian Republic. The results obtained are widely used in the educational process at the departments of propaedeutics of internal diseases and faculty therapy of the medical faculty of the Kabardino-Balkarian State University. Approbation of the dissertation work. The results of the research were presented at the North Caucasian Scientific-Practical Conference "Topical Questions of Emergency Therapy at the Pre-Hospital Stage" (Nalchik, 2004, 2006), the regional conference "Problems of Clinical Pharmacology and Modelling in Pharmacology and Biomedicine" (Rostov-on-Don, 2006), the scientific-practical conference with international participation "Profession and Medicine" (Moscow, April, 2007, 2008), and the international scientific-practical conference of the Southern Federal District (Vladikavkaz, 2007). The approbation of the dissertation took place on 4 July 2008 at the extended meeting of the department of propaedeutics of internal diseases of the medical faculty of the Kabardino-Balkarian State University named after Kh.M. Berbekov. Structure of the dissertation. The author's scientific research is set out on 156 pages of typewritten text, and consists of an introduction, three chapters ("Review of the Literature", "Material and Methods of Research", "Results and Their Discussion"), a conclusion, conclusions and practical recommendations. The dissertation is illustrated with 18 tables and 12 figures. The bibliography is represented by 312 sources, including 151 domestic and 161 foreign authors.