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. 2005 Dec;62(12):890–894. doi: 10.1136/oem.2005.020354

Long driving time is associated with haematological markers of increased cardiovascular risk in taxi drivers

J Chen 1, Y Chen 1, W Chang 1, D Christiani 1
PMCID: PMC1740933  PMID: 16299099

Abstract

Aims: To examine the association between driving time and changes in haematological markers of increased risks for cardiovascular diseases (CVD).

Methods: The authors conducted a cross sectional analysis of baseline data from the Taxi Drivers' Health Study cohort in Taipei, Taiwan. They retrieved information on comorbidity, laboratory tests, age, and anthropometric measures from medical records of 1157 subjects (mean age 44.6 (SD 8.6) years). Whole blood cell (WBC) count was used as the primary haematological marker for increased CVD risk, and platelet count and haematocrit as the secondary markers. Standardised questionnaires were implemented to collect information on demographics, lifestyle, work related physical and psychosocial factors, and driving time profiles. Multiple regression was used to estimate the adjusted effects of driving time on three haematological markers.

Results: The mean measured hematological marker was 6656 (SD 1656) cells x106/l for WBC, 47.2 (SD 3.5) % for hematocrit, and 243 (SD 52) cells x109/l for platelets. The driving time was 264 (SD 76) hours/month. Compared with drivers who drove ⩽208 hours/month (1st quartile cut off), drivers who drove >208 hours/month had a higher WBC count (by 317 x106/l; 95% CI 99 to 535), haematocrit (by 0.8%; 95% CI 0.3 to 1.2), and platelets (7.9 x109/l; 95% CI 1.0 to 14.8). After adjusting for conventional CVD risk factors (age, sex, smoking, hypertension, diabetes, and hypercholesterolaemia), obesity, alcohol drinking, regular exercise, and sociodemographics (education, marital status, income, and so on), long driving time was still associated with significant increases in WBC and platelets, whereas the effect on haematocrit was diminished and became statistically non-significant. Additional controls for physical workload, self-perceived job stress, and job dissatisfaction did not alter the associations with increased WBC and platelets.

Conclusions: Longitudinal studies are needed to confirm the observed cross sectional association and to further examine the specific occupational exposures accountable for the association between driving time and haematological markers of systemic inflammation and haemostatic alteration.

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Selected References

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  1. Alfredsson L., Hammar N., Hogstedt C. Incidence of myocardial infarction and mortality from specific causes among bus drivers in Sweden. Int J Epidemiol. 1993 Feb;22(1):57–61. doi: 10.1093/ije/22.1.57. [DOI] [PubMed] [Google Scholar]
  2. Barron H. V., Harr S. D., Radford M. J., Wang Y., Krumholz H. M. The association between white blood cell count and acute myocardial infarction mortality in patients > or =65 years of age: findings from the cooperative cardiovascular project. J Am Coll Cardiol. 2001 Nov 15;38(6):1654–1661. doi: 10.1016/s0735-1097(01)01613-8. [DOI] [PubMed] [Google Scholar]
  3. Belkić K., Emdad R., Theorell T. Occupational profile and cardiac risk: possible mechanisms and implications for professional drivers. Int J Occup Med Environ Health. 1998;11(1):37–57. [PubMed] [Google Scholar]
  4. Bellet S., Roman L., Kostis J. The effect of automobile driving on catecholamine and adrenocortical excretion. Am J Cardiol. 1969 Sep;24(3):365–368. doi: 10.1016/0002-9149(69)90430-5. [DOI] [PubMed] [Google Scholar]
  5. Bigert C., Klerdal K., Hammar N., Hallqvist J., Gustavsson P. Time trends in the incidence of myocardial infarction among professional drivers in Stockholm 1977-96. Occup Environ Med. 2004 Dec;61(12):987–991. doi: 10.1136/oem.2004.012781. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bigert Carolina, Gustavsson Per, Hallqvist Johan, Hogstedt Christer, Lewné Marie, Plato Nils, Reuterwall Christina, Schéele Patrik. Myocardial infarction among professional drivers. Epidemiology. 2003 May;14(3):333–339. [PubMed] [Google Scholar]
  7. Black Paul H., Garbutt Lisa D. Stress, inflammation and cardiovascular disease. J Psychosom Res. 2002 Jan;52(1):1–23. doi: 10.1016/s0022-3999(01)00302-6. [DOI] [PubMed] [Google Scholar]
  8. Cannon C. P., McCabe C. H., Wilcox R. G., Bentley J. H., Braunwald E. Association of white blood cell count with increased mortality in acute myocardial infarction and unstable angina pectoris. OPUS-TIMI 16 Investigators. Am J Cardiol. 2001 Mar 1;87(5):636-9, A10. doi: 10.1016/s0002-9149(00)01444-2. [DOI] [PubMed] [Google Scholar]
  9. Chen J-C, Chan W. P., Katz J. N., Chang W. P., Christiani D. C. Occupational and personal factors associated with acquired lumbar spondylolisthesis of urban taxi drivers. Occup Environ Med. 2004 Dec;61(12):992–998. doi: 10.1136/oem.2003.011775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Chen Jiu-Chiaun, Dennerlein Jack T., Shih Tung-Sheng, Chen Chiou-Jong, Cheng Yawen, Chang Wushou P., Ryan Louise M., Christiani David C. Knee pain and driving duration: a secondary analysis of the Taxi Drivers' Health Study. Am J Public Health. 2004 Apr;94(4):575–581. doi: 10.2105/ajph.94.4.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Chen Jiu-Chiuan, Chang Wen-Ruey, Shih Tung-Sheng, Chen Chiou-Jong, Chang Wushou P., Dennerlein Jack T., Ryan Louise M., Christiani David C. Using exposure prediction rules for exposure assessment: an example on whole-body vibration in taxi drivers. Epidemiology. 2004 May;15(3):293–299. doi: 10.1097/01.ede.0000121378.62340.a7. [DOI] [PubMed] [Google Scholar]
  12. Cheng Yawen, Luh Wei-Ming, Guo Yue-Liang. Reliability and validity of the Chinese version of the Job Content Questionnaire in Taiwanese workers. Int J Behav Med. 2003;10(1):15–30. doi: 10.1207/s15327558ijbm1001_02. [DOI] [PubMed] [Google Scholar]
  13. Daleva M., Piperova-Dalbokova D., Hadjiolova I., Mincheva L. Changes in the excretion of corticosteroids and catecholamines in tractor-drivers. Int Arch Occup Environ Health. 1982 Feb;49(3-4):345–352. doi: 10.1007/BF00377943. [DOI] [PubMed] [Google Scholar]
  14. Egelund N. Spectral analysis of heart rate variability as an indicator of driver fatigue. Ergonomics. 1982 Jul;25(7):663–672. doi: 10.1080/00140138208925026. [DOI] [PubMed] [Google Scholar]
  15. Evans G. W., Carrère S. Traffic congestion, perceived control, and psychophysiological stress among urban bus drivers. J Appl Psychol. 1991 Oct;76(5):658–663. doi: 10.1037/0021-9010.76.5.658. [DOI] [PubMed] [Google Scholar]
  16. Fransson Eleonor, De Faire Ulf, Ahlbom Anders, Reuterwall Christina, Hallqvist Johan, Alfredsson Lars. The risk of acute myocardial infarction: interactions of types of physical activity. Epidemiology. 2004 Sep;15(5):573–582. doi: 10.1097/01.ede.0000134865.74261.fe. [DOI] [PubMed] [Google Scholar]
  17. Gustavsson P., Alfredsson L., Brunnberg H., Hammar N., Jakobsson R., Reuterwall C., Ostlin P. Myocardial infarction among male bus, taxi, and lorry drivers in middle Sweden. Occup Environ Med. 1996 Apr;53(4):235–240. doi: 10.1136/oem.53.4.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Hannerz H., Tüchsen F. Hospital admissions among male drivers in Denmark. Occup Environ Med. 2001 Apr;58(4):253–260. doi: 10.1136/oem.58.4.253. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Hartvig P., Midttun O. Coronary heart disease risk factors in bus and truck drivers. A controlled cohort study. Int Arch Occup Environ Health. 1983;52(4):353–360. doi: 10.1007/BF02226900. [DOI] [PubMed] [Google Scholar]
  20. Hasegawa Takashi, Negishi Toyoko, Deguchi Miyako. WBC count, atherosclerosis and coronary risk factors. J Atheroscler Thromb. 2002;9(5):219–223. doi: 10.5551/jat.9.219. [DOI] [PubMed] [Google Scholar]
  21. Hedberg G. E., Jacobsson K. A., Janlert U., Langendoen S. Risk indicators of ischemic heart disease among male professional drivers in Sweden. Scand J Work Environ Health. 1993 Oct;19(5):326–333. doi: 10.5271/sjweh.1467. [DOI] [PubMed] [Google Scholar]
  22. Irace Concetta, Ciamei Monica, Crivaro Andrea, Fiaschi Elio, Madia Angela, Cortese Claudio, Gnasso Agostino. Hematocrit is associated with carotid atherosclerosis in men but not in women. Coron Artery Dis. 2003 Jun;14(4):279–284. doi: 10.1097/01.mca.0000071769.74379.49. [DOI] [PubMed] [Google Scholar]
  23. Kannel W. B., Anderson K., Wilson P. W. White blood cell count and cardiovascular disease. Insights from the Framingham Study. JAMA. 1992 Mar 4;267(9):1253–1256. [PubMed] [Google Scholar]
  24. Kannel W. B., Belanger A., D'Agostino R., Israel I. Physical activity and physical demand on the job and risk of cardiovascular disease and death: the Framingham Study. Am Heart J. 1986 Oct;112(4):820–825. doi: 10.1016/0002-8703(86)90480-1. [DOI] [PubMed] [Google Scholar]
  25. Lee C. D., Folsom A. R., Nieto F. J., Chambless L. E., Shahar E., Wolfe D. A. White blood cell count and incidence of coronary heart disease and ischemic stroke and mortality from cardiovascular disease in African-American and White men and women: atherosclerosis risk in communities study. Am J Epidemiol. 2001 Oct 15;154(8):758–764. doi: 10.1093/aje/154.8.758. [DOI] [PubMed] [Google Scholar]
  26. Liao Duanping, Heiss Gerardo, Chinchilli Vernon M., Duan Yinkang, Folsom Aaron R., Lin Hung-Mo, Salomaa Veikko. Association of criteria pollutants with plasma hemostatic/inflammatory markers: a population-based study. J Expo Anal Environ Epidemiol. 2005 Jul;15(4):319–328. doi: 10.1038/sj.jea.7500408. [DOI] [PubMed] [Google Scholar]
  27. Libby Peter. Inflammation in atherosclerosis. Nature. 2002 Dec 19;420(6917):868–874. doi: 10.1038/nature01323. [DOI] [PubMed] [Google Scholar]
  28. Mattiasson I., Lindgärde F. The effect of psychosocial stress and risk factors for ischaemic heart disease on the plasma fibrinogen concentration. J Intern Med. 1993 Jul;234(1):45–51. doi: 10.1111/j.1365-2796.1993.tb00703.x. [DOI] [PubMed] [Google Scholar]
  29. Nieto F. J., Szklo M., Folsom A. R., Rock R., Mercuri M. Leukocyte count correlates in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Epidemiol. 1992 Sep 1;136(5):525–537. doi: 10.1093/oxfordjournals.aje.a116530. [DOI] [PubMed] [Google Scholar]
  30. Noguchi T., Tsujisaki M., Imai K., Dodo M., Tabuchi Y., Nakajima T., Kajita A., Hayashi I., Sugiura T., Kumahara Y. Relationship among risk factors of atherosclerosis, leukocyte count, and soluble intercellular adhesion molecule-1. Intern Med. 1998 Feb;37(2):123–126. doi: 10.2169/internalmedicine.37.123. [DOI] [PubMed] [Google Scholar]
  31. Palmer K. T., Haward B., Griffin M. J., Bendall H., Coggon D. Validity of self reported occupational exposures to hand transmitted and whole body vibration. Occup Environ Med. 2000 Apr;57(4):237–241. doi: 10.1136/oem.57.4.237. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Pearson Thomas A., Mensah George A., Alexander R. Wayne, Anderson Jeffrey L., Cannon Richard O., 3rd, Criqui Michael, Fadl Yazid Y., Fortmann Stephen P., Hong Yuling, Myers Gary L. Markers of inflammation and cardiovascular disease: application to clinical and public health practice: A statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation. 2003 Jan 28;107(3):499–511. doi: 10.1161/01.cir.0000052939.59093.45. [DOI] [PubMed] [Google Scholar]
  33. Páramo José A., Orbe Josune. Hemostasis, inflammation and cardiovascular disease. Clin Lab. 2002;48(9-10):463–470. [PubMed] [Google Scholar]
  34. Rosengren A., Anderson K., Wilhelmsen L. Risk of coronary heart disease in middle-aged male bus and tram drivers compared to men in other occupations: a prospective study. Int J Epidemiol. 1991 Mar;20(1):82–87. doi: 10.1093/ije/20.1.82. [DOI] [PubMed] [Google Scholar]
  35. Ruberg Frederick L., Leopold Jane A., Loscalzo Joseph. Atherothrombosis: plaque instability and thrombogenesis. Prog Cardiovasc Dis. 2002 Mar-Apr;44(5):381–394. doi: 10.1053/pcad.2002.123469. [DOI] [PubMed] [Google Scholar]
  36. Sato S., Taoda K., Kawamura M., Wakaba K., Fukuchi Y., Nishiyama K. Heart rate variability during long truck driving work. J Hum Ergol (Tokyo) 2001 Dec;30(1-2):235–240. [PubMed] [Google Scholar]
  37. Schwartz J. Air pollution and blood markers of cardiovascular risk. Environ Health Perspect. 2001 Jun;109 (Suppl 3):405–409. doi: 10.1289/ehp.01109s3405. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Thaulow E., Erikssen J., Sandvik L., Stormorken H., Cohn P. F. Blood platelet count and function are related to total and cardiovascular death in apparently healthy men. Circulation. 1991 Aug;84(2):613–617. doi: 10.1161/01.cir.84.2.613. [DOI] [PubMed] [Google Scholar]
  39. Tüchsen F. Stroke morbidity in professional drivers in Denmark 1981-1990. Int J Epidemiol. 1997 Oct;26(5):989–994. doi: 10.1093/ije/26.5.989. [DOI] [PubMed] [Google Scholar]
  40. Wiktorin C., Vingård E., Mortimer M., Pernold G., Wigaeus-Hjelm E., Kilbom A., Alfredsson L. Interview versus questionnaire for assessing physical loads in the population-based MUSIC-Norrtälje Study. Am J Ind Med. 1999 May;35(5):441–455. doi: 10.1002/(sici)1097-0274(199905)35:5<441::aid-ajim1>3.0.co;2-a. [DOI] [PubMed] [Google Scholar]
  41. van der Beek A. J., Meijman T. F., Frings-Dresen M. H., Kuiper J. I., Kuiper S. Lorry drivers' work stress evaluated by catecholamines excreted in urine. Occup Environ Med. 1995 Jul;52(7):464–469. doi: 10.1136/oem.52.7.464. [DOI] [PMC free article] [PubMed] [Google Scholar]

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