Multiple Risk Factor Syndrome In Japanese Male Workers: A Work-Site Cohort Study

摘要

Objectives: To demonstrate the relationships between multiple risk factor syndrome (MRFS) and atherosclerotic events, comparing with hypercholesterolemia group (hTC), in Japanese male workers by conducting a work-site cohort study. Methods: From 1986 to 1992, 163 male eligible subjects (MRFS group: n=87; hTC group: n=76) aged 30 years or more, working at a single department store in Tokyo were enrolled, and followed-up until 1998 to observe the occurrence of atherosclerotic events (coronary heart diseases, cerebral infarctions and retinal artery hemorrhages). We defined MRFS group as subjects who met the following criteria: high blood pressure (diastolic blood pressure >= 90 mmHg and/or systolic blood pressure >= 150 mmHg, or the initiation of hypertension therapy), hypertriglyceridemia (serum triglycerides>=160 mg/dl), hyperglycemia (defined by the criteria by Japan Diabetes Society.1970), and obesity (BMI: >= 24.0 kg/m2) at baseline. To compare MRFS group, we also defined hTC group as subjects whose serum total cholesterol level at baseline was 280 mg/dl or more. Results: Eight coronary heart disease cases, 3 cerebral infarction cases and 4 retinal artery hemorrhage cases were observed in MRFS group. On the other hand, no atherosclerotic case was observed in hTC group during the period. Mantel-Haenszel procedure showed that age-adjusted atherosclerosis incidence was significantly higher in MRFS group than that in hTC group (p<0.05). Conclusions: MRFS group are more likely to experience atherosclerotic events compared with hTC group. It is important to focus on health education regarding atherosclerotic outcome prevention towards a cluster of metabolic risk factors, MRFS, in work-site as well as severe hypercholesterolemia. Abbreviation BMI: Body mass index Introduction In recent years it has been proposed that hypertension is part of a cluster of metabolic risk factors involving hyperlipidemia and hyperglycemia, with hyperinsulinemia as the common link 1 2 . The link is known as 'Multiple Risk Factor Syndrome (MRFS)' or 'Metabolic Syndrome X 1 ' or 'Deadly Quartet 3 ’ or ‘Insulin Resistant Syndrome 2 ’. Furthermore, researchers also reported close relationships between MRFS and systemic atherosclerotic vascular disease such as coronary heart disease (CHD) 3 . However, in Japan few longitudinal studies have undergone assessment of the risk of MRFS regarding atherosclerotic vascular outcomes. The majority of the studies have concentrated on selected clinical sample, and it appears that either limited or no data have been demonstrated by epidemiological studies such as a work-site based study. Moreover, although hypercholesterolemia has been already established as a risk factor of CHD and managed intensely and routinely in work-site, a cluster of subclinical metabolic risk factors seemed to be passed by and noticed insufficiently. One main purpose of this study is to strike a note of warning to health care professionals against such a cluster, MRFS. Therefore, we designed this study to focus on the comparison between MRFS and severe hypercholesterolemia in this study in terms of occurrence of atherosclerotic events in Japanese meddle-aged male workers,. Subjects and Methods We conducted a work-site cohort study at a single department store company in Tokyo. From 1986 to 1992, the company had an average annual participation of 2849 male employees in the regular health-checkups. Of those health screened, 206 male participants, aged 30 years or more at baseline, were designed to allocate into the two groups by the following criteria: MRFS group and hTC group. However, since 6 subjects met both criteria and 37 subjects in hTC group had been initiated medication during follow-up period, we excluded 43 cases from the analysis. Thus, 163 final eligible subjects (MRFS group: n=87; hTC group: n=76) were enrolled into this study, and followed up until 1998 over 6 years on average to observe the occurrence of three atherosclerotic events: