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international Heart and Vascular Disease Journal • Volume 8, № 26, June 2020
Journal of the Cardioprogress Foundation
LEADING ARTICLE
Risk of arterial hypertension
and work-related stress in the population
aged 25-64 years in Russia/Siberia (WHO — MONICA psychosocial program)
V. V. Gafarov12, E. A. Gromova12, D. O.Panov12, A. V. Gafarova12, S. V. Astrakov3, I. V. Gagulin12.
1 Research Institute of Therapy and Preventive Medicine, Novosibirsk, Russia.
2 The Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, Novosibirsk, Russia.
3 Novosibirsk State Medical University, Novosibirsk, Russia.
Authors
Gafarov V. Valery*, M.D., Ph.D., doctor of sciences, head of the Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, head of the Laboratory of Psychological and Sociological Aspects of Disease, Research Institute of Therapy and Preventive Medicine, Novosibirsk, Russia.
Gromova A. Elena, M.D., Ph.D., doctor of sciences, senior researcher at the Laboratory of Psychological and Sociological Aspects of Disease, Research Institute of Therapy and Preventive Medicine, the Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, Novosibirsk, Russia.
Panov O. Dmitry, M.D., Ph.D., senior researcher at the Laboratory of Psychological and Sociological Aspects of Disease, Research Institute of Therapy and Preventive Medicine, the Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, Novosibirsk, Russia.
Gafarova V. Almira, M.D., Ph.D., senior researcher at the Laboratory of Psychological and Sociological Aspects of Disease, Research Institute of Therapy and Preventive Medicine, the Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, Novosibirsk, Russia.
Astrakov V. Sergei, M.D., Ph.D., professor in the Department of Anesthesiology and Intensive Care Medicine, Novosibirsk State Medical University, Novosibirsk, Russia.
Gagulin V. Igor, senior researcher at the Laboratory of Psychological and Sociological Aspects of Disease, Research Institute of Therapy and Preventive Medicine, the Interdepartmental Laboratory of Cardiovascular Disease Epidemiology, Novosibirsk, Russia.
* Corresponding author. Tel.: +79231735863. E-mail: valery.gafarov@gmail.com
Objective
To study how work-related stress affects the risk of arterial hypertension (AH) within a 16-year observation period in people aged 25-64 years in Novosibirsk, Siberia. Materials and methods
We examined a random representative sample that consisted of people aged 25-64 years from a district in Novosibirsk in 1994 as a part of the III screening of the WHO-MONICA psychosocial program (men: n=657, mean age 44.3±0.4 years, response rate — 82.1 %; women: n=689, mean age 45.4±0.4 years, response rate — 72.5 %). The screening program included collecting socio-demographic data. The level of work-related stress was assessed with the Karasek scale. The period of prospective observation was 16 years. We used a chi-squared test (x2) to assess statistical significance in differences between groups. We used monofactorial and polyfactorial Cox regression model to assess relative risk (RR). We considered pi0.05 to be statistically significant.
Results
High work-related stress levels were identified in 29.5 °% of men and 31.6 °% of women (%2= 2.574; u=2 P=0.276). The level of work-related stress was higher in men who worked in a job that involved moderate manual labour compared with women (34.7 % in men vs 17.7 % in women; yf=7.755 df=2; p=0.021). At 16 years of observation RR of AH was higher in men (RR= 1.4) than in women (RR= 1.27). RR was higher in widowed men (RR=2.5), in women aged25-44, 45-54, 55-64 years (RR=1.699, RR=2.427and RR=2.694 respectively). Conclusions
The level of work-related stress is similar in men and women. At the same time, at 16 years of observation RR of AH was higher in men compared with women.
Key words: work-related stress, arterial hypertension, gender differences, relative risk. Conflict of interests: none declared.
Received: 17.02.2020 Accepted: 26.03.2020
Introduction
The WHO defines "work-related stress" as being the response people may have when presented with work demands and pressures that are not matched to their knowledge and abilities and which challenge their ability to cope [1]. 28 % of working people in Europe (41 million people) are struggling with works-related stress [2]. Work-related stress is associated with cardiovascular disease (CVD) [3], musculoskeletal disorders (especially back pain) [4], anxiety depression [5], fatigue [6, 7], insomnia [8] and alcohol abuse [9]. It was suggested that more than 10 %o of work-related disorders are associated with stress at workplace [10]. Finally, work-related stress leads to significant financial losses. For example, estimated total annual cost of stress in the EU is twenty billion dollars (EU-15). This figure is based on the costs to employers resulting from absenteeism, loss of productivity, health care costs and social welfare costs [11, 12].
Work-related stress was identified as an important independent risk factor for arterial hypertension (AH) [13, 14].
This study investigates the effect of work-related stress on the risk of arterial hypertension in men and women aged 25-64 years coming from different social groups in an open population in Novosibirsk, Russia, within a 16-year observation period.
Materials and methods
We examined a random representative sample that consisted of people aged 25-64 years from a district in Novosibirsk in 1994 as a part of the III screening of the WHO-MONICA psychosocial program (men: n=657, mean age 44.3±0.4 years, response rate — 82.1 %%; women: n=689, mean age 45.4±0.4 years, response rate — 72.5 %).
The representative sample was formed according to the WHO-MONICA psychosocial program protocol requirements [15].
The screening program included the following parts: 1) Collecting socio-demographic data according to the standardized WHO-MONICA psychosocial program epidemiologic protocol that included ID, ad-
Table 1. Distribution of the population aged 25-64 years by age groups (III screening program, 1994)
Gender Age groups Total
25-34 years 35-44 years 45-54 years 55-64 years
n % n % n % n %
Men 169 50.8 136 45.9 177 47.7 175 50.6 657
Women 164 49.2 160 5 194 52.3 171 49.4 689
Total 333 100 296 100 371 100 346 100 1346
X2=2.087 df=3; p=0.555
Table 2. Distribution of the population aged 25-64 years by marital status (III screening program, 1994)
Gender Marital status Total
Single (Never married) Married Divorced and not remarried Widowed and not remarried
n % n % n % n %
Men 51.1 559 51.7 40 35.7 13 20 657
Women 43 48.9 522 48.3 72 64.3 52 80 689
Total 88 100 1081 100 112 100 65 100 1346
X2=33.113 df=3; p=0.0001
Table 3. Distribution of the population aged 25-64 years by level of educational attainment (III screening program, 1994)
Level of educational attainment
Gender Tertiary education Incomplete tertiary education, secondary specialized education Secondary education Incomplete secondary education, primary education Total
n % n % n % n %
Men 186 49.2 178 44.3 150 49.2 143 55.6 657
Women 192 50.8 224 55.7 155 50.8 114 44.4 685
Total 378 100 402 100 305 100 257 100 1342
X2=8.133 df=3; p=0.043
Table 4. Distribution of the population aged 25-64 years by professional status (III screening program, 1994)
Gender Professional status*
SE MLE MAN ITW HMW MMW LMW Students Retired Total
n % n % n % n % n % n % n % n % n %
Men 28 84.8 55 55.6 65 50.8 84 42 144 88.9 167 63.3 21 17.1 9 81.8 84 34.7 657
Women 5 15.2 44 44.4 63 49.2 116 58 18 11.1 97 36.7 102 82.9 2 18.2 158 65.3 605
Total 33 100 99 100 128 100 200 100 162 100 264 100 123 100 11 100 242 100 1262
X2=238.16 df=8; p=0.001
Comment
* Professional status: SE — senior executives MLE — mid-level executives MAN — managers
dress, full name, date of birth, registration date; gender — 1 — male, 2 — female. Distribution of the population by age groups is presented in Table 1.
Marital status (Table 2), level of educational attainment (Table 3) and professional status (Table 4) were also taken into consideration.
2) Testing using the psychosocial methods. In order to assess the level of work-related stress we used the Karasek scale [15]. The analyzed risk factor was assessed at baseline without registering its change over time. All methods were strictly standardized and met all WHO-MONICA psychosocial program requirements [15].
The collected data were analyzed in MONICA Data Center in Helsinki, Finland. Quality control was per-
ITW — IT workers HMW — Heavy manual workers MMW — Moderate manual workers LMW — Light manual workers
formed in MONICA Quality Control Centers: Dundee (Scotland), Prague (Czech Republic), Budapest (Hungary). All the collected data were approved [15].
All men and women with CVD (coronary artery disease, cerebrovascular disease, AH, myocardial infarction, diabetes) identified before or during the screening process were excluded from the study. The study eventually included 384 women and 190 men aged 25-64 years. The period of prospective observation was 16 years.
The primary endpoint of this study was new arterial hypertension identified during the observation period. We used the information from the results of annual physical exams, patient histories, hospital discharge papers, papers from the district health
Table 5. Work-related stress in the population aged 25-64 years (III screening program, 1994)
Age 25-34 35-44 45-54 55-64 25-64
Gender M W M W M W M W M W
N % N % N % N % N % N % N % N % N % N %
Family stress
Low 28 17.8 22 17.5 25 16.4 22 18.2 32 26.4 30 20.4 38 27.1 20 14.8 123 21.6 94 17.8
Moderate 84 53.5 66 52.4 82 53.9 57 47.1 55 45.5 76 51.7 58 41.4 69 51.1 279 48.9 268 50.7
Severe 45 28.7 38 30.2 45 29.6 42 34.7 34 28.1 41 27.9 44 31.4 46 34.1 168 29.5 167 31.6
Total 157 100 126 100 152 100 121 100 121 100 147 100 140 100 135 100 570 100 529 100
X2=0.076 u= 2; p=0.963 X2=1.288 u=2; p=0.525 X2= 1.577 u= 2; p=0.455 X2=6.495 u=2; p=0.039 X2= 2.574 u=2;p=0.276
Table 6. Work-related stress and marital status in the population aged 25-64 years (III screening program)
Work-related stress Marital status
Single (Never married) Married Divorced and not remarried Widowed and not remarried;
M W M W M W M WW
N % N % N % N % N % N % N % N %
Low 7 21.2 7 22.6 83 20.4 70 17.4 6 21.4 11 20.4 4 50 6 15
Moderate 14 42.4 16 51.6 197 48.4 206 51.1 14 50 27 50 2 25 19 47.5
Severe 12 36.4 8 25.8 127 31.2 127 31.5 8 28.6 16 29.6 2 25 15 37.5
Total 33 100 31 100 407 100 403 100 28 100 LO 100 8 100 40 100
X2=0.872 df=2; p=0.647 X2=1.286 df=2; p=0.526 X2=0.017 df=2; p=0.992 X2=4.986 df= 2; p=0.083
Table 7. Work-related stress and level of educational attainment in the population aged 25-64 years
(III screening program)
Work-related stress Education level
Tertiary education Incomplete tertiary education, secondary specialized education Secondary education Incomplete secondary education, primary education
M W M W M W M W
N % N % N % N % N % N % N % N %
Low 27 19.4 24 16.6 25 19.4 28 17.1 22 22 31 24.8 26 24.1 10 11.1
Moderate 69 49.6 75 51.7 66 51.2 83 50.6 39 39 56 44.8 53 49.1 50 55.6
Severe 43 30.9 46 31.7 38 29.5 53 32.3 39 39 38 30.4 29 26.9 30 33.3
Total 139 100 5 100 129 100 164 100 100 100 125 100 108 100 90 100
X2= 0.401 df=2; p=0.818 X2=0.407 df= 2; p=0.816 X2= 1.828 df=2; p=0.401 X2=5.626 df= 2; p=0.06
clinics, death reports, conversations with relative, and autopsy reports.
During the annual physical exams we performed standardized blood pressure measurements on the right hand using mercury sphygmomanometers (we registered the first phase of Korotkoff sounds as systolic arterial pressure and the fifth phase as the diastolic blood pressure and then analyzed the mean). We considered patients to have arterial hypertension if systolic blood pressure was 140 mmHg or higher and/or diastolic blood pressure was 90 mmHg and higher in those individuals who did not receive hy-potensive therapy. Hypertension group also included men with normal blood pressure readings if they were taking hypotensive therapy during the exam or stopped taking it less then two weeks prior.
We identified 229 new cases of AH in women and 46 cases in men over the observation period.
The statistical analysis was performed using the SPSS Version 11.5 [16]. We used a chi-squared test (x2) to assess statistical significance in differences
between groups [17]. We used monofactorial and polyfactorial Cox regression model to assess relative risk (RR) and confidence intervals (CI) [18]. We considered ps0.05 to be statistically significant.
Results
We identified high work-related stress levels in 29.5 % of men and 31.6 % of women (x2= 2.574; u=2, p=0.276). We identified higher levels of stress in men (31.4 %) and women (34.1 %) of older age group of 5564 years (x2=6.495 u=2; p=0.039) (Table 5).
We identified no differences in work-related stress in men and women depending on marital status (Table 6).
Similarly, we identified no differences in work-related stress in men and women depending on the level of educational attainment (Table 7).
Table 8 presents compared level of work-related stress depending on professional level. We identified higher stress levels in men who worked in a job that involved manual labour compared with women of this
Table 8. Work-related stress and professional status in the population aged 25-64 years (III screening program)
WRS Professional status*
SE MLE MAN ITW HMW MMW LMW
M W M W M W M W M W M W M W
N % N % N % N % N % N % N % N % N % N % N % N % N % N %
L 3 12.5 2 50 10 22.7 8 22.9 10 23.8 19 43.2 13 19.7 27 31 21 19.6 2 22.2 26 22 27 34.2 4 28.6 23 28.8
M 10 41.7 1 25 26 59.1 18 51.4 20 47.6 19 43.2 30 45.5 46 52.9 53 49.5 4 44.4 51 43.2 38 48.1 7 50 39 48.8
S 11 45.8 1 25 8 18.2 9 25.7 12 28.6 6 13.6 23 34.8 14 16.1 33 30.8 3 33.3 41 34.7 14 17.7 3 21.4 18 22.5
Total 24 100 4 100 44 100 35 100 42 100 44 100 66 100 87 100 107 100 9 100 118 100 79 100 14 100 80 100
X2=3.129 df= 2; p= 0.19 X2= 0.72 df= 2; p= 0.698 X2= 4.775 df=2; p= 0.092 X2=7.721 df=2; p=0.021 X2=0.089 df= 2; p= 0.957 X2=7.755 df=2; p= 0.021 x2= 0.01 df=2; p= 0.995
Comment: * WRS — work-related stress L — low M —moderate S — severe
SE — senior executives MLE — mid-level executives
MAN — managers
ITW — IT workers
HMW — heavy manual workers
MMW — moderate manual workers
LMW — light manual workers
Table 9. Work-related stress and relative risk of arterial hypertension in the open population aged 25-64 years
(monofactorial Cox regression model)
Observation period Gender Men Women
Age group P RR 95 % CI p RR 95 % CI
16 years Lower bound Upper bound Lower bound Upper bound
25-64 0.05 1.4 1.021 5.491 0.034 1.276 1.018 1.6
Table 10. Work-related stress and relative risk of arterial hypertension in the open population aged 25-64
years over 16-years observation period (multifactorial Cox regression model)
Gender Reference group--. Risk group Men Women
p RR 95 % CI p RR 95 % CI
Lower bound Upper bound Lower bound Upper bound
No stress Work-related stress 0.3 1.5 0.5 3.9 0.021 1.166 0.917 1.482
Married Single (Never married) 0.09 2.4 0.5 11 0.568 1.163 0.692 1.955
Divorced and not remarried 0.1 1.7 0.06 9 0.134 1.581 0.868 2.880
Widowed and not remarried 0.01 2.5 1.4 14 0.647 1.176 0.587 2.357
Higher education Tertiary/Secondary specialized education 0.8 1.1 0.3 4.2 0.106 1.319 0.943 1.844
Secondary education 0.7 0.7 0.1 3.9 0.780 1.056 0.718 1.554
Incomplete secondary/Primary education 0.5 0.6 0.1 2.5 0.062 1.543 0.979 2.433
MAN. and ITW Job type 0.8 1.4 0.04 15 0.998 1.002 0.239 4.202
24-34 years 35-44 years 0.08 1.4 0.9 13 0.003 1.699 1.204 2.399
45-54 years 0.2 1.7 0.02 3.4 0.0001 2.472 1.737 3.518
55-64 years 0.1 1.9 0.01 4 0.0001 2.694 1.556 4.666
Comment: MAN — managers, ITW — IT workers.
group (34.7 % in men vs 17.7 % in women; %2=7.755 df=2; p=0.021).
Monofactorial regression analysis showed increased AH risk over the 16-year observation period in individuals who had work-related stress (men: RR=1.4; CI 1.021-5.491; p<0.05; women: RR=1.27; CI 1.018-1.6; p<0.034) (Table 9).
Multifactorial modeling that included social parameters and age showed that RR of AH in women who had work-related stress was 1.166 (CI 0.9171.482; p<0.021) and RR in men was 1.5 (CI 0.5-3.9; p>0.05). In the groups that differed in marital status RR was the highest in the widowed men — 2.5 (CI 1.4-
14; p<0.01). No statistically significant differences in AH RR were identified in men and women who had different levels of educational attainment and professional statuses. The comparison of 25-34 age group with the other three age groups showed that the AH RR in women who had work-related stress was 1.699 in the 35-44 age group (CI 1.204-2.399; p<0.003); 2.472 in the 45-54 age group (CI 1.7373.518; p<0.0001) and 2.694 in the 55-64 age group (CI 1.556-4.666; p<0.0001). We didn't identify any statistically significant differences in the RR of AH in men of different age groups who had work-related stress (Table 10).
Discussion
Multiple factors are associated with the development of CVD and especially AH, including genetic, biological and psychosocial factors. It is well known that working conditions, age and gender can cause the development of AH. Furthermore, some data suggest that the effect of work-related stress on AH development differed between men and women, indicating that it contributed to a different extent depending on gender [19].
In the investigated population of working-age individuals (25-64 years) work-related stress was quite prevalent — almost /3 of men and women struggled with high levels of stress at the workplace. Men and women in the older age group (55-64 years) experienced more work-related stress. The level of work-related stress was higher in men who worked in a job that involved moderate manual labour compared with women, which means that "blue collars" are subjected to higher levels of stress compared with "white collars" [13].
Over the 16-year observation period the RR of AH in individuals with work-related stress was noted to be slightly higher in men (1.4) then in women (1.27). After marital status, level of educational attainment, professional status and age were included in the Cox-regression model along with work-related stress, AH risk increased in women (RR=1.6), widowed men (RR=2.5), and in women of all age groups (35-44 years: RR=1.69; 45-54 years: RR=2.47; 55-64 years: RR= 2.64).
Our study was similar to Wiernik et al. 2013 [20] cohort study that included 122 816 individuals (84 994 men). This study identified that work-related stress
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Conclusions
1. High work-related stress levels were identified in 29.5 % of men and 31.6 % of women (%2= 2.574; u=2 P;=0.276). We identified higher levels of stress in men (31.4 %) and women (34.1 %) of older age group of 55-64 years (x2=6.495 u=2; p=0.039).
2. The level of work-related stress was higher in men who worked in a job that involved moderate manual labour compared with women (34.7 % in men vs 17.7 % in women; %2=7.755 df=2; p=0.021). We identified no differences in work-related stress in men and women depending on the level of educational attainment.
3. Monofactorial regression analysis showed that AH RR in individuals with work-related stress was slightly higher in men (1.4) then in women (1.27) over the 16-year observation period.
4. Multifactorial modeling showed a rise in the RR of AH in several groups: in women who had work-related stress (RR=1. 166); in the widowed men (RR=2.5) and in women of the 35-44 age group (RR=1.699), of the 45-54 age group (RR=2.472) and of the 55-64 age group (RR=2.694).
Conflict of interests: None declared.
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