Objective: In Japan, there is growing concern that employees' health condition has been worsening under the severe labor conditions of the continuing recent deep recession. To determine trends in the prevalence of cardiovascular risk factors among employees, we analyzed 32 yr of systematic surveillance of urban Japanese employed men.
Subjects and methods: The surveyed population included male employees aged 40 to 59 yr who worked for four companies, a trading company, two banks and a company maintaining expressways in Osaka. Surveillance of cardiovascular risk factors was conducted from 1977 to 2008. We examined the annual mean values of systolic blood pressure, diastolic blood pressure, body mass index, and total serum cholesterol, and the prevalence of hypertension, obesity, hypercholesterolemia, smoking, alcohol drinkers, and high risk individuals who had two or more risk factors: (high blood pressure, high glucose and dyslipidemia).
Results: The total number of employees aged 40-59 yr increased from 822 in 1977 to 2,651 in 1992, but then declined gradually to 1,455 in 2008. Among men aged 40-49 and 50-59, the prevalence of hypertension decreased from 25% and 39% in 1977 to 14% and 23% in 1992, respectively. However, the respective prevalence of hypertension started to rise thereafter to 29% and 47% in 2008, accompanied by an increase in blood pressure levels and the prevalence of antihypertensive medication use. Mean body mass index and the prevalence of obesity showed significant upward linear trends from the mid-1980's to 2008. Therefore, we speculate that the increase in blood pressure levels seen after the early 1990's associated with an increase in obesity. However the proportion of hypertension among non-overweight men also increased between the early 1990's and 2008, suggesting other factors are also involved in the increase of hypertension. The prevalence of hypercholesterolemia and high-risk individuals with obesity also increased in recent years. Mean total cholesterol level showed a linear increase from 195 mg/dl for men aged 40-49 and 196 mg/dl for men aged 50-59 in 1977 to 204 mg/dl and 207 mg/dl in 2008, respectively. The prevalence of high-risk individuals with obesity was 13% for men aged 40-49 and 15% for men aged 50-59 in 2008. Among men aged 50-59, the prevalence of non-overweight high-risk individuals became higher than that of high-risk individuals with obesity over time.
Conclusions: Although these findings were limited to the study companies, our data support evidence that Japanese employees have become increasingly at risk of cardiovascular diseases under the severe working conditions experienced since the 1990's. It is important to improve working conditions as well as personally control risk factors from the point of public health.