The relationship between lifestyle risk factors and depression in Korean older adults: a moderating effect of gender

Background: Little is known regarding the role of gender as a possible modulator in determining the associations between lifestyle risk factors and depression in older adults. Objectives: This study examined whether gender modulates the relationship between depression and lifestyle risk factors in Korean adults aged 65 years and older (n = 3700). Methods: Data were obtained from the 2016 and 2018 Korea National Health and Examination Survey. The primary outcome was depression, assessed with the patient health questionnaire-9. As exposures, smoking habits, at-risk alcohol consumption, and physical inactivity were assessed with a standardized questionnaire. In addition, mean adequacy ratio (MAR) as an indicator of overall nutritional inadequacy was assessed with dietary intakes of macro- and micronutrients. Results: In men only, either two or three and more risk factors were significantly associated with higher depression risk (OR (95% confidence interval, CI) = 2.886 (1.003-8.299) and OR (95% CI) = 3.109 (1.064-9.097), respectively). In women only, either two or three and more risk factors were also significantly associated with higher depression risk (OR (95% CI) = 1.505 (1.067-2.124) and OR (95% CI) = 2.828 (1.527-5.239), respectively). In particular, the presence of smoking habits and MAR were the major determinants of depression (OR (95% CI) = 1.835 (1.09-3.10) and OR (95% CI) = 1.585 (1.125-2.233), respectively) in women only. Finally, a moderation analysis with the Hayes PROCESS Macro showed a significant moderating effect of gender (beta (95% CI) = 0.633 (0.206 similar to 1.060)) on the relationship between risk factors and depression. In addition, the slope of the relationship was much steeper in women than in men. Conclusion: Current findings suggest that lifestyle risk factors are more closely associated with depression risk in women than in men.