Annals of Occupational and Environmental Medicine

  • Volume 34
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  • Pages.9.1-9.13
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  • 2022
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  • 1225-3618(pISSN)
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  • 2052-4374(eISSN)
The Korean Society of Occupational & Environmental Medicine (대한직업환경의학회)
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Association between long working hours and liver enzymes: evidence from the Korea National Health and Nutrition Examination Survey, 2007-2017

  • Ji-Hun Song (Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea) ;
  • Hyoung-Ryoul Kim (Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea) ;
  • Dong-Wook Lee (Public Healthcare Center, Seoul National University Hospital) ;
  • Jeehee Min (Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea) ;
  • Yu Min Lee (Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea) ;
  • Mo-Yeol Kang (Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea)
  • Received : 2021.11.04
  • Accepted : 2022.04.26
  • Published : 2022.12.31
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Abstract

Background: Long working hours causes several health risks, but little is known about its effects on the liver. This study aimed to examine the correlation between working hours and abnormal liver enzyme levels. Methods: We used data from the Korea National Health and Nutrition Examination Survey IV-VII. For the final 15,316 study participant, the information on working hours was obtained through questionnaires, and liver enzyme levels, consisting of serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), through blood tests. The relationship between weekly working hours and abnormal levels of liver enzymes was analyzed using multiple logistic regression, and a trend test was also conducted. Results: In male, working ≥ 61 hours per week was significantly associated with elevated AST and ALT levels compared with working 35-52 hours per week. Even after adjusting for covariates, the odds ratios (ORs) of abnormal AST and ALT increased by 1.51 (95% confidence interval: 1.20-2.05) and 1.25 (1.03-1.52), respectively, and a dose-response relationship was observed. This association was more prominent among the high-risk group, such as those aged > 40 years, obese individuals, worker on non-standard work schedule, pink-collar workers, or temporary worker. No correlation was observed in female. Conclusions: Long working hours are associated with abnormal liver function test results in male. Strict adherence to statutory working hours is necessary to protect workers' liver health.

Keywords

Acknowledgement

We thank the team of the Korea National Health and Nutrition Examination Survey (KNHANES) and Korea Disease Control and Prevention Agency (KDCA) for providing the original KNHANES data. The authors are solely responsible for the contents of the present study, and they do not necessarily represent the official views of the KDCA.

References

  1. Organization for Economic Cooperation and Development (OECD). Hours Worked (Indicator). Paris, France: OECD; 2021.
  2. Bannai A, Tamakoshi A. The association between long working hours and health: a systematic review of epidemiological evidence. Scand J Work Environ Health 2014;40(1):5-18.
  3. Kivimaki M, Jokela M, Nyberg ST, Singh-Manoux A, Fransson EI, Alfredsson L, et al. Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603,838 individuals. Lancet 2015;386(10005):1739-46.
  4. Park S, Kook H, Seok H, Lee JH, Lim D, Cho DH, et al. The negative impact of long working hours on mental health in young Korean workers. PLoS One 2020;15(8):e0236931.
  5. Sato Y, Miyake H, Theriault G. Overtime work and stress response in a group of Japanese workers. Occup Med (Lond) 2009;59(1):14-9.
  6. Artazcoz L, Cortes I, Escriba-Aguir V, Cascant L, Villegas R. Understanding the relationship of long working hours with health status and health-related behaviours. J Epidemiol Community Health 2009;63(7):521-7.
  7. Virtanen M, Jokela M, Nyberg ST, Madsen IE, Lallukka T, Ahola K, et al. Long working hours and alcohol use: systematic review and meta-analysis of published studies and unpublished individual participant data. BMJ 2015;350:g7772.
  8. Zhu Y, Liu J, Jiang H, Brown TJ, Tian Q, Yang Y, et al. Are long working hours associated with weight-related outcomes? A meta-analysis of observational studies. Obes Rev 2020;21(3):e12977.
  9. Vere CC, Streba CT, Streba LM, Ionescu AG, Sima F. Psychosocial stress and liver disease status. World J Gastroenterol 2009;15(24):2980-6.
  10. Lee EY, Choi HY, Cho H, Kim BH, Ki M. Health behavior associated with liver enzymes among obese Korean adolescents, 2009-2014. PLoS One 2018;13(1):e0190535.
  11. Agrawal S, Dhiman RK, Limdi JK. Evaluation of abnormal liver function tests. Postgrad Med J 2016;92(1086):223-34.
  12. Patel DA, Srinivasan SR, Xu JH, Chen W, Berenson GS. Persistent elevation of liver function enzymes within the reference range is associated with increased cardiovascular risk in young adults: the Bogalusa Heart Study. Metabolism 2007;56(6):792-8.
  13. Ruhl CE, Everhart JE. Elevated serum alanine aminotransferase and gamma-glutamyltransferase and mortality in the United States population. Gastroenterology 2009;136(2):477-485.e11.
  14. Kim HC, Nam CM, Jee SH, Han KH, Oh DK, Suh I. Normal serum aminotransferase concentration and risk of mortality from liver diseases: prospective cohort study. BMJ 2004;328(7446):983.
  15. Asrani SK, Devarbhavi H, Eaton J, Kamath PS. Burden of liver diseases in the world. J Hepatol 2019;70(1):151-71.
  16. Paik JM, Golabi P, Younossi Y, Mishra A, Younossi ZM. Changes in the global burden of chronic liver diseases from 2012 to 2017: the growing impact of NAFLD. Hepatology 2020;72(5):1605-16.
  17. Song E, Kim JA, Roh E, Yu JH, Kim NH, Yoo HJ, et al. Long working hours and risk of nonalcoholic fatty liver disease: Korea National Health and Nutrition Examination Survey VII. Front Endocrinol (Lausanne) 2021;12:647459.
  18. Lee Y, Mun E, Park S, Lee W. Long working hours are associated with a higher risk of non-alcoholic fatty liver disease: a large population-based Korean cohort study. PLoS One 2021;16(7):e0255118.
  19. Mun E, Lee W, Nam MW, Kim HI, Kim H, Lee Y, et al. Cross-sectional association between long working hours and liver function: the Kangbuk Samsung Health Study. BMJ Open 2020;10(12):e041595.
  20. Ochiai Y, Takahashi M, Matsuo T, Sasaki T, Fukasawa K, Araki T, et al. Objective and subjective working hours and their roles on workers' health among Japanese employees. Ind Health 2020;58(3):265-75.
  21. Lefebvre P, Staels B. Hepatic sexual dimorphism - implications for non-alcoholic fatty liver disease. Nat Rev Endocrinol 2021;17(11):662-70.
  22. Chapter IV: working hours and recess. Labor Standard Act. https://elaw.klri.re.kr/kor_service/lawView.do?hseq=54708&lang=ENG. Updated 2020. Accessed October 1, 2021.
  23. Korean Enforcement Decree of the Industrial Accident Compensation Insurance Act and Public Notice of what is necessary to determine approval for cerebro-cardiovascular disease and musculoskeletal disease as occupational diseases. https://www.law.go.kr/LSW//admRulInfoP.do?admRulSeq=2100000196483. Updated 2020. Accessed October 1, 2021.
  24. Health examination implementation guidelines (Korean): No. 2020-313. https://mohw.go.kr/react/modules/viewHtmlConv.jsp?BOARD_ID=5900&CONT_SEQ=362673&FILE_SEQ=310166. Updated 2020. Accessed January 4, 2022.
  25. Korea National Health and Nutrition Examination Survey: statistical survey outlines (Korean). http://meta.narastat.kr/metasvc/svc/SvcMetaDcDtaPopup.do?orgId=117&confmNo=117002&kosisYn=Y. Updated 2019. Accessed January 4, 2022.
  26. Yki-Jarvinen H. Non-alcoholic fatty liver disease as a cause and a consequence of metabolic syndrome. Lancet Diabetes Endocrinol 2014;2(11):901-10.
  27. Kim C, Cho Y. Working conditions and leisure-time physical activity among waged workers in South Korea: a cross-sectional study. J Occup Health 2015;57(3):259-67.
  28. Schneider S, Becker S. Prevalence of physical activity among the working population and correlation with work-related factors: results from the first German National Health Survey. J Occup Health 2005;47(5):414-23.
  29. Kaizu S, Kishimoto H, Iwase M, Fujii H, Ohkuma T, Ide H, et al. Impact of leisure-time physical activity on glycemic control and cardiovascular risk factors in Japanese patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry. PLoS One 2014;9(6):e98768.
  30. Tanaka R, Tsuji M, Kusuhara K, Kawamoto T; Japan Environment and Children's Study Group. Association between time-related work factors and dietary behaviors: results from the Japan Environment and Children's Study (JECS). Environ Health Prev Med 2018;23(1):62.
  31. Fazel Y, Koenig AB, Sayiner M, Goodman ZD, Younossi ZM. Epidemiology and natural history of non-alcoholic fatty liver disease. Metabolism 2016;65(8):1017-25.
  32. Joung JY, Cho JH, Kim YH, Choi SH, Son CG. A literature review for the mechanisms of stress-induced liver injury. Brain Behav 2019;9(3):e01235.
  33. Chida Y, Sudo N, Kubo C. Does stress exacerbate liver diseases? J Gastroenterol Hepatol 2006;21(1 Pt 2):202-8.
  34. Swain MG. I. Stress and hepatic inflammation. Am J Physiol Gastrointest Liver Physiol 2000;279(6):G1135-8.
  35. Liu YZ, Chen JK, Zhang Y, Wang X, Qu S, Jiang CL. Chronic stress induces steatohepatitis while decreases visceral fat mass in mice. BMC Gastroenterol 2014;14(1):106.
  36. Ishtiaq SM, Khan JA, Arshad MI. Psychosocial-stress, liver regeneration and weight gain: a conspicuous pathophysiological triad. Cell Physiol Biochem 2018;46(1):1-8.
  37. Russ TC, Kivimaki M, Morling JR, Starr JM, Stamatakis E, Batty GD. Association between psychological distress and liver disease mortality: a meta-analysis of individual study participants. Gastroenterology 2015;148(5):958-966.e4.
  38. Okechukwu CA. Long working hours are linked to risky alcohol consumption. BMJ 2015;350:g7800.
  39. Frone MR. Are work stressors related to employee substance use? The importance of temporal context assessments of alcohol and illicit drug use. J Appl Psychol 2008;93(1):199-206.
  40. Friedmann PD. Clinical practice. Alcohol use in adults. N Engl J Med 2013;368(4):365-73.
  41. Agarwal S, Fulgoni VL 3rd, Lieberman HR. Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data. Nutr J 2016;15(1):62.
  42. Iqbal U, Perumpail BJ, Akhtar D, Kim D, Ahmed A. The epidemiology, risk profiling and diagnostic challenges of nonalcoholic fatty liver disease. Medicines (Basel) 2019;6(1):41.
  43. Choi H, Oh HJ, Shin JS, Lim M, Kim SK, Kang HT, et al. Relationship between shift work and liver enzymes: a cross-sectional study based on the Korea National Health and Examination Survey (2007-2015). Ann Occup Environ Med 2019;31:e15.
  44. Chun HR, Cho I, Choi Y, Cho SI. Effects of emotional labor factors and working environment on the risk of depression in pink-collar workers. Int J Environ Res Public Health 2020;17(14):5208.
  45. Virtanen M, Kivimaki M, Joensuu M, Virtanen P, Elovainio M, Vahtera J. Temporary employment and health: a review. Int J Epidemiol 2005;34(3):610-22.
  46. Palmisano BT, Zhu L, Stafford JM. Role of estrogens in the regulation of liver lipid metabolism. Adv Exp Med Biol 2017;1043:227-56.
  47. Shi L, Feng Y, Lin H, Ma R, Cai X. Role of estrogen in hepatocellular carcinoma: is inflammation the key? J Transl Med 2014;12(1):93.
  48. Chaplin TM, Hong K, Bergquist K, Sinha R. Gender differences in response to emotional stress: an assessment across subjective, behavioral, and physiological domains and relations to alcohol craving. Alcohol Clin Exp Res 2008;32(7):1242-50.
  49. Crum RM, Muntaner C, Eaton WW, Anthony JC. Occupational stress and the risk of alcohol abuse and dependence. Alcohol Clin Exp Res 1995;19(3):647-55.
  50. Esper LH, Furtado EF. Gender differences and association between psychological stress and alcohol consumption: a systematic review. J Alcohol Drug Depend 2013;1(3):116-20.
  51. Jacobs JA. Measuring time at work: are self-reports accurate. Mon Labor Rev 1998;121:42-53.
  52. Imai T, Kuwahara K, Miyamoto T, Okazaki H, Nishihara A, Kabe I, et al. Validity and reproducibility of self-reported working hours among Japanese male employees. J Occup Health 2016;58(4):340-6.
  53. Chang Y, Ryu S, Sung E, Jang Y. Higher concentrations of alanine aminotransferase within the reference interval predict nonalcoholic fatty liver disease. Clin Chem 2007;53(4):686-92.
  54. Sarin SK, Kumar M, Eslam M, George J, Al Mahtab M, Akbar SM, et al. Liver diseases in the Asia-Pacific region: a Lancet Gastroenterology & Hepatology Commission. Lancet Gastroenterol Hepatol 2020;5(2):167-228.
  55. Swain MG. Fatigue in liver disease: pathophysiology and clinical management. Can J Gastroenterol 2006;20(3):181-8.