Assessment of the risk of ischemic heart disease and its relevant factors among Japanese police officers

OBJECTIVES: Compared to other public employees, police officers have higher absence rates due to heart diseases, and ischemic heart disease (IHD) is one of the most frequent causes of death in their occupational life. The aim of this study was to investigate the prevalence of the risk factors for IHD among police officers and to examine its association with working conditions and lifestyles. METHODS: First, 58 male police officers who developed IHD from 1996 to 2011 and 116 age- and rank-matched controls who were free from cerebro- and cardiovascular diseases were compared with respect to the prevalence of traditional risk factors five years before the onset of IHD. Then, the prevalence of IHD risk factors, and the frequency of metabolic syndrome (MetS) by age group, working condition and lifestyle were investigated in a cross-sectional survey of data of 1,539 male police officers and 153 male office workers in a prefectural police force. RESULTS: In the case control study, the IHD cases had significantly higher prevalences of hypertension (p<0.001), hyper-LDL-cholesterolemia (p<0.05), glucose intolerance (p<0.05), and hyperuricemia (p<0.05) before the onset of IHD. Multiple logistic regression analysis revealed that hypertension (odds ratio [95% confidence interval] : 3.96 [1.82-8.59]), glucose intolerance (3.28 [1.34-8.03]), hypo-HDL-cholesterolemia (2.26 [1.03-4.97]), and hyper-LDL-cholesterolemia (2.18 [1.03-4.61]) were independently associated with the development of IHD (model chi-square, p<0.001; correct classification rate, 77.0%). In the cross sectional analyses, among the police officers, abdominal obesity (waist circumference of ≥ 85 cm) was significantly more frequent (57.3% vs. 35.3%, p<0.001) and the prevalence of dyslipidemia and glucose intolerance increased with age more remarkably than in the general office workers. In the age-group of 45-59 years, the clustering number of risk factors in individuals (1.8 vs. 1.4, p<0.01) and the frequency of MetS (25.0 vs. 15.5, p<0.1) were greater in the police officers than the office workers. Among the police officers, subjects with MetS had significantly higher rates of shift work (33.6% vs. 25.4%, p<0.01), lack of sound sleep (42.5% vs. 33.7%, p<0.01), and heavy drinking (12.8 vs. 6.3%, p<0.01) than those without MetS. CONCLUSIONS: In this study, the development of IHD in police officers was significantly associated with traditional risk factors, especially with hypertension, dyslipidemia and glucose intolerance. The increase with age of the prevalence of IHD risk factors and the frequency of MetS were greater in police officers than office workers. Irregular working conditions, such as shift work, long working time, and unfavorable lifestyles, e.g. alcohol drinking and poor sleeping conditions, may influence the higher prevalence of risk factors for IHD in police officers.