Relationship between Perceived Job-Stress and Glycosylated Hemoglobin in White-Collar Workers

Transcription

1 Industrial Health, ORIGINAL ARTICLES Relationship between Perceived Job-Stress and Glycosylated Hemoglobin in White-Collar Workers Norito KAWAKAMI,' Shunichi ARAKP1) Takeshi HAYASHI2) and Takeshi MASUMOTO2) 1) Department of Public Health, Faculty of Medicine, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan 2) Hitachi Health Care Center, Ohse-cho, Hitachi, Ibaraki 317, Japan (Received June 26, 1989 and in revised form September 6, 1989) Abstract: Cesana et al. (1985) have indicated that glycosylated hemoglobin (HbAk) may be a potential measure of job-stress. To examine this observation further, a questionnaire study on job-stress and health-related behaviors together with measurement of HbA, and fasting plasma glucose (FPG) were conducted for 129 male white-collar workers at a multiphasic health examination. It was found that a total of 102 subjects with the FPG level lower than 110 mg/dl had received no medical treatment ; the score of job-dissatisfaction was significantly correlated with their HbAk level (p < 0.05). None of possible confounders, i.e., age, job-overload, overtime, number of cigarettes per day, alcohol consumption, obesity and blood tests other than FPG, were significantly correlated with HbAk; the score of job-dissatisfaction was not significantly correlated with the FPG level. It is indicated that HbAk may be a sensitive measure of job-dissatisfaction; further studies are needed to clarify psychophysiological mechanisms underlying the effects of job-dissatisfaction on the HbA, level. Key words : Job stress -Job satisfaction Glycosylated hemoglobin -Fasting plasma glucose hite collar workers W INTRODUCTION Recently, recognition and control of psychosocial job-stress are considered essential for disease prevention and health promotion in industry. For these purposes, many questionnaire and physiological measures of job-stress have been developed.1) However, the use of questionnaire methods is limited by its subjective nature. Physiological and neuroendcrinological methods are often expensive and complicated for a large sample study. Offprint requests to: Prof. S. Araki, Department of Public Health, Faculty of Medicine, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

2 150 N. KAWAKAMI, et al. Proportion of glycosylated hemoglobin (HbA1c) in total hemoglobin is an integrated measure of changes in metabolism of glucose in diabetic patients,2) and is used for a screening of diabetic mellitus.3) It has been shown that HbA1c reflects the time-averaged serum glucose concentration for the preceding eight to twelve weeks.4) Recently, Cesana et al.5) reported that the level of HbA1c is higher in blue collar workers than in clerical workers ; whereas no significant difference is observed in the level of fasting blood sugar between the two groups. The blue collar workers engaged in stressful conditions, such as shift work, noisy environment and low job-satisfaction; therefore it was explained that the findings resulted from frequent elevation in the blood glucose level due to job-stress mediated by sympathetic nervous system and catecholamine secretion. Then Cesana et alproposed HbA1c as a stable and inexpensive measure of chronic job-stress. Higher levels of HbA1c were also reported in medical students before a school examination. However, it is not adequately investigated whether increased HbA1c levels are caused by job-stress independent of health-related behaviors which are associated with job-stress, such as smoking and alcohol drinking.') To confirm the hypothesis presented by Cesana and his collegues, the present study examines the relationships between HbA1c and selected sources of psychosocial job-stress, i. e. job-overload and job-dissatisfaction, where the effects of major health-related behaviors, such as smoking and alcohol drinking, were considered. SUBJECTS AND METHODS Subjects 307 male employees of 10 worksites in an electric corporation, aged 30 or more years, came to a multiphasic health examination from July 2 to August 11 in They were surveyed with questionnaires concerning job-stress and health related behaviors. Blood analysis including HbA1c and fasting plasma glucose (FPG) was made for these subjects. 275 or 90% of these workers responded the questionnaire survey. 146 blue collar workers were excluded because their physical activities during working hours were greatly different each other and might be confounding. The following analysis was made in 129 white collar workers. 10 subjects were omitted because they had been diagnosed as diabetes mellitus or they received medical treatment for diabetus mellitus or other disorders. Another 17 were excluded because they had 110 mg/dl or higher FPG concentration, which is the normal limit recommended by the Committee on the Diagnosis of Diabetes Mellitus in Japan!) Mean age } standard deviation of the 102 subjects was 38.0 } 5.1. Mean value } standard deviation of HbA1c, was 5.28 }1 0.31; that for FPG was 98.5 ± 5.9. Urinary sugar was negative in all these subjects.

3 JOB-STRESS AND GLYCOSYLATED HEMOGLOBIN 151 Methods After fasting overnight, the subjects came to the examination center at about 8 :00 am. The questionnaires concerning background data, job-stress variables and health-related behaviors were handed to the subjects. Blood sample was taken at about 9 : 00 am. During the waiting time, subjects asked to be in rest and stop smoking. Health examination included blood pressure measurent, blood analysis and physical examination. The job-stress items, which are 4-choice response scales, were subjected to a principal components factor analysis with varimax rotation ; two factors with eigen values more than 1.0 were extracted ; these items were classified into either of two factors in which their factor loadings were greater. A total score of each group of items was used as a measure of the correspondent factor of job-stress (see Appendix). Job-dissatisfaction (4 items) assesses how much the subject personally dissatisfied with content of his work and human relations at the workplace; the score was ranged from 0 to 12. Job-overload (3 items) refers to the amount of quantitative and qualitative pressure perceived by workers; the score was ranged from 0 to 9. Alpha coefficients of internal consistencies were 0.65 for job-dissatisfaction and 0.56 for job-overload. Overtime per month was also assessed in the questionnaires. Health-related behaviors consisted of number of cigarettes currently smoked per day, alcohol consumption, obesity, physical activity in leisure time, sleeping hours and freqency of coffee and tea drinking with sugar. Alcohol consumption was assessed according to the type of alcohol and frequency of consumption, and dose (ml) of pure ethanol intake per week was estimated. Obesity was measured with a body mass index which was calculated by determining a ratio of body weight (Kg) to the square of height (m). Physical exercise in leisure time was assessd by the single question whether he had regular habits of sports or exercises. Frequency of coffee and tea drinking with sugar was measured by number of cups per day of coffee and tea with sugar. HbA1c was measured by an automatic analyzer (Kyoto Daiichi Kagaku HA- 8121) by means of high performance liquid chromatography.9) This method measures HbA1c, apart from HbA1a, HbAlb, and HbF, but dose not eliminate pre-hba1c labile fraction affected by rapid fluctuation of blood glucose.4) Laboratory blood tests provided measures of FPG, hemoglobin, total cholesterol, triglyceride, GOT, GPT, LDH, gamma-gtp, uric acid and creatine. Relations of age, job-stress variables, health-related behaviors and health examination data to HbA1c, and FPG were examined using Pearson's correlation coefficients (rs). Student's t-test was used to examine difference in HbA1c, and FPG between groups classified based on the variables.

4 152 N. KAWAKAMI, et al. Fig. 1. Relationship between job-dissatisfaction score and hemoglobin Ak in 102 subjects RESULTS Job-dissatisfaction score was positively correlated with HbA1c (Fig. 1). Jobdissatisfaction score was not significantly correlated with FPG (p >0.05). None of the following variables were significantly correlated with HbA1c (p > 0.05) : job-overload score, overtime and possible confounders, i. e., age, alcohol consumption, obesity, sleeping time, frequency of coffee and tea drinking with sugar, blood pressures and results of blood tests other than FPG (hemoglobin, total cholesterol, triglyceride, GOT, GPT, LDH, gamma-gtp, uric acid, creatine). Number of cigarettes currently smokerd per day was significantly correlated with HbA1c in neither the total subjects nor 95 subjects except 7 ex-smokers (p >0.05). HbA1c, were not significantly different between the groups classified on the basis of physical exercises and worksites (p >0.05).

5 JOB-STRESS AND GLYCOSYLATED HEMOGLOBIN 153 DISCUSSION In the present study, HbA1c was significantly correlated with job-dissatisfaction score. The results suggest that HbA1c is a possible indicator of job-dissatisfaction. The criteria used to eliminate possible diabetic patients, i. e. less than 110 mg/dl in FPG, may incorporate some subjects with impaired glucose tolerance into the subjects. However, it seems unlikely that this level of change in the glucose metabolism restricts daily work and consequently leads to job-dissatisfaction. Since job-dissatisfaction score was not significantly correlated with FPG, higher HbA1c levels in the subjects with higher job-dissatisfaction in non-smokers are mainly attributable to non-diabetic mechanisms. 1) Emotional reactions due to job-dissatisfaction may cause frequent release of counterregulatory hormones such as cortisol, growth hormone and catecholamines10) and a subsequent rise in blood glucose.11) 2) Changes in dietary habits under stressful conditions might cause elevated HbA1c levels, as pointed out by Cesana et al.5) The present study failed to show the associations of HbA1c with obesity, alcohol consumption, frequency of coffee and tea drinking with sugar, and selected serum indicators of nutritional states, such as total cholesterol, triglyceride and uric acid. Other dietary change which leads to frequent and temporal elevations of blood glucose should be considered in a further study. The relationships between HbA1c and the workload variables, i. e., overtime or perceived job-overload, were not observed in the present study. Hinkle and Wolf s early work12) suggested that blood glucose changes vary with the type of emotions; anger increases blood sugar level and anxiety decreases it. It has been reported thet job-overload is mainly correlated with anxiety.13) The results may be explained by such complex interaction between blood glucose and emotions caused by job-stress. The present study could not eliminate labile fraction, i. e. pre-hba1c, from HbA1c. It is not clear whether the increased HbA1c level related to job-dissatisfaction is due to transient increase in blood glucose in a recent priod or increase in the mean levels of blood glucose for a long duration. Further investigations are needed to re-examine the present results in a larger number of subjects and to explain psychophysiological mechanisms for the effects of job-dissatisfaction on the HbA1c level. ACKNOWLEDGMENTS The authors wish to thank Dr. T. Arakawa and Mrs. S. Shoji at Hitachi Health Care Center. Part of this study was supported by a grant-in-aid for scientific research from the Ministry of Education. Science and Culture, Japan.

6 154 N. KAWAKAMI, et al REFERENCES 1) ILO. Psychosocial factors at work. Occupational safety and health series No. 56. Geneva: ILO, 1986 : ) Koenig RJ, Peterson CM, Jones RL, Saudek C, Lehrman M, Carami A. Correlation of glucose regulation and hemoglobin Aic in diabetes mellitus. New Engl J Med 1976; 295 : ) Dunn PJ, Cole RA, Soeldner JS, Gleason RE, Reproducibility of hemoglobin Al and sensitivity to various degrees of glucose intolerance. Ann Int Med 1979; 91: ) Bunn HF. Evaluation of glycosylated haemoglobin in diabetic patients. Diabetes 1981; 30 : ) Cesana G, Panza G, Ferrario M, Zanettini R, Arnoldi M, Grieco A. Can glycosylated hemoglobin be a job stress parameter? JOM 1985; 27 : ) Netterstryhm B, Danborg L,Olesen H. Glycated hemoglobin as a measure of physiological stress. Behav Med 1988; 14: ) House JS. Occupational stress and the mental and physical health of factory workers. Ann Arbor : Institute for Social Research, University of Michigan,1980 : ) Kosaka J, Akanuma Y, Hakura A, Hirata Y, Kawade R, Kuzutani K, Mimura G, Nakayama H, Sakamoto N,Shigeta S. Report of the Committee on Diagnosis of Diabetes Mellitus. J Japan.Diab Soc 1982; 28: (In Japanese) 9) Schneck AG, Schroeder WA. The relation between the minor components of whole normal human adult hemoglobin as isolated by chromatography and starch block electrophoresis. J Am Chem Soc 1961; 83 : ) Rose RM, Sachar E. Psychoendocrinology. In: Williams RH, ed. Textbook of endocrinology. 6th ed. Philadelphia : WB Saunders, 1981: ) Eigler N, Sacca L, Sherwin R. Synergistic interactions of physiologic increments of glucagon, epinephrine, and cortisol in the dog. J Clin Invest 1979; 63 : ) Hitkle L, Wolf S. A summary of experimental evidence relating Iife stress to diabetes mellitus. J Mt Sinai Hosp 1952; 19 : ) Broadbent DE. The clinical impact of job design. Br J Clinical Psychology 1985; 24: APPENDIX 1. Measure of job-dissatisfaction :* Do you feel your job is meaningful for you? Do you feel your job is suited to you? Do you feel you have good human relations at your worksite? Do you have troubles in doing your work in recent 6 month? 2. Measure of job-overload.* Do you feel the amount of your work is too much? Do you feel your job is highly responsible? Are you able to control the pace of your job? *A 4-choice response scale was used ("very much", "moderate", "a little", "none" ).