The Association between Combined Lifestyle Factors and All-Cause and Cause-Specific Mortality in Shiga Prefecture, Japan

Background: To decrease mortality, the benefit of combined healthy lifestyles has been suggested but is still unclear, especially for cause-specific mortality. We examined the relationship between combined lifestyle factors and all-cause and cause-specific mortality in Shiga prefecture, Japan. Methods: This was an ecological study of 19 municipalities, using the data from the 2008-2012 standard mortality ratio (SMR) reported by the Ministry of Health and Welfare and the 2015 Health and Nutrition Survey in Shiga prefecture. The health behaviors score was calculated based on five factors (ranging from 0 to 5): diet quality (assessed adherence to dietary reference intake for Japanese), smoking, alcohol drinking, regular exercise, and sleep duration. In the multiple linear regression, the relationships between the health behaviors score and SMR of all-cause, cancer, heart diseases, and cerebrovascular diseases were estimated by sex. Results: The health behaviors score was negatively associated with the cancer SMR in women (beta= -0.968,p= 0.011). For other causes, no significant association was found for either sex. A greater proportion of those who never smoked (beta= -0.780,p= 0.016) and those who had a higher quality diet (beta= -0.703,p= 0.048) were associated with lower cancer SMR in women. Women's intake of some micronutrients, particularly fruits, was higher than men. This study suggests that a combination of health behaviors, especially never smoking and high-quality diet intake are associated with lower cancer SMR in women and could be helpful in prolonging life expectancy.