title: Depressive symptoms of female nursing staff working in stressful environments and their association with serum creatine kinase and lactate dehydrogenase - a preliminary study.
abstract: BACKGROUND
  The activity of creatine kinase (CK) in serum has recently been reported to be potentially associated with several types of depression. The aim of this study is to evaluate whether serum enzymes, including CK, vary even in a healthy population with depressive symptoms caused by work-related stress. We gave questionnaires and blood examinations to 93 healthy female nursing home workers and did an enzyme-linked immunosorbent assay for the quantitative detection of CK isozyme muscle-type M chain (CK-MM) in serum.
  
  
  RESULTS
  Depressive symptoms were determined using the Center for Epidemiologic Studies Depression (CES-D) scale and compared with the results of the blood examination and serum CK-MM levels. The CES-D results showed significant negative correlations with total CK and lactate dehydrogenase (LDH) activities and CK-MM level (r = -0.29, p = 0.0062; r = -0.29, p = 0.0065; r = -0.33, p = 0.0016, respectively).
  
  
  CONCLUSIONS
  Total CK and LDH activities and serum CK-MM level appear to be associated with the depressive symptoms of healthy nurses working in stressful environments, although the significance level was relatively low. The simultaneous detection of serum CK and LDH activities or serum CK-MM level and LDH activity may be useful as an indicator of depressive symptoms, at least for female nursing staff with work-related stress.
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan ; Prima Meat Packers, Ltd., Tsuchiura, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Kato
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan ; Department of Agriculture, University of Miyazaki, Miyazaki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakakibara
authors.affiliation: Department of Neurology and Psychosomatic Medicine, Bantane Hospital, Fujita Health University School of Medicine, Nagoya, Japan ; Institute of Medical, Pharmaceutical & Health Sciences, Kanazawa University, Kanazawa, Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Tsuboi
authors.affiliation: Faculty of Nursing, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Tatsumi
authors.affiliation: Prima Meat Packers, Ltd., Tsuchiura, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Akimoto
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Shimoi
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Department of Neurology and Psychosomatic Medicine, Bantane Hospital, Fujita Health University School of Medicine, Nagoya, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan ; Faculty of Applied Life Science, Nippon Veterinary and Life Science University, Musashino, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Department of Food and Nutritional Sciences, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Ohashi
keywords: Center for Epidemiologic Studies Depression scale; Creatine kinase; Depressive symptom; Healthy female nursing staff