THE EFFECTS OF SLEEPING TYPE ON THE CARDIOVASCULAR RISK FACTORS IN JAPANESE WORKERS ENGAGED IN LONG WORKING TIME.

“过劳死”是由过度工作和慢性疲劳引起的死亡，被认为与睡眠状况有关。发展以过度工作评价慢性疲劳的方法，对预防心血管疾病引起的“过劳死”具有重要意义。目的探讨工作时间或睡眠类型与精神状态、慢性疲劳等心血管疾病危险因素的关系。方法采用自评抑郁量表（SDS）和累积疲劳症状指数（CFSI）作为因变量，其他潜在协变量作为自变量，采用ANCOVA分析方法，将1505名男性日工分为6组，分别以早晚睡眠量表和月工作时间对睡眠类型的影响进行分析。结果晨型组BMI、平均血压、HbA1c、血清总胆固醇、HDL胆固醇均显著升高。ANCOVA结果显示，在工作【大于等于】260小时/月组，夜间型的SDS和CFSI得分显著高于其他组。结论260小时/月以上的工作时间增加了疲劳症状，提示睡眠类型对精神状态、慢性疲劳等心血管危险因素有影响。

Background "Karo-shi", the death caused by overworking and chronic fatigue, is considered to be related to sleeping condition. And a developing of the method of evaluating chronic fatigue by overworking may be very important to prevent "karo-shi" caused by cardiovascular disease.Aim To clarify the relationships between working hours or sleeping type and mental status and chronic fatigue as risk factors of cardiovascular disease.Methods On 1505 male day workers, effects of sleeping type according to Morning-Evening Scale and working hours/month subdivided into 6 group were determined using Self rating Depression Scale(SDS) and Cumulative Fatigue Symptom Index(CFSI) as dependent variables, and other potential covariates as independent variables by ANCOVA.Results In the group Morning type, BMI, mean blood pressure, HbA1c, total serum cholesterol and HDL cholesterol were significantly increased. The results of ANCOVA indicate that in the group working 【greater than or equal】260 hours/month and that scores of SDS and CFSI in evening type were significantly higher than other groups.Conclusions The present results clarified that 260 or more hours/month working hours increased fatigue symptoms, and suggests that sleeping type affects on the mental status, chronic fatigue and other cardiovascular risk factors.