[Health-related lifestyle and mental health among inhabitants of a city in Japan].

AIM

Few studies have linked mental health to lifestyle factors in the Japanese general population. The present investigation was conducted to examine whether mental health is associated with a health-related lifestyle and how the strength of the association, if any, differs across sex and age groups, using health survey data for inhabitants of Japan.

METHODS

The data used were obtained from a questionnaire survey on lifestyle and health. In 1998, the questionnaires were mailed to 2,288 subjects selected from among the inhabitants of a city in Japan, of whom 1,642 subjects (71.8%) responded. The present study included 1,343 subjects who completed all the items that were used in the analysis. The General Health Questionnaire (GHQ) -12 was used as an indicator of mental health, with 4 points or higher (high score) indicating poor mental health. Information on eight different lifestyle parameters was also obtained. Logistic regression was used to calculate the odds ratio (OR) of having poor mental health for each lifestyle.

RESULTS

Subjects in poor mental health had a lower mean score for a healthy lifestyle than those in good mental health. The difference in the mean score increased with age among men, while it decreased with age among women. The OR for having poor mental health among non-exercisers was higher in the older age group among men, while it was higher in the younger age group among women. A strong association between sleep hours and mental health was observed in the older age group among men, while it was seen in the younger age groups among women. Dietary factors in general showed a clearer association with mental health among women than among men, except for the consumption of salty foods, the association of which with mental health was more evident among men.

CONCLUSIONS

Mental health was found to be significantly associated with health-related lifestyles in the Japanese population. The strength of the association for each lifestyle varied considerably across sex and age groups.