Effect of gender on the association between cumulative cardiovascular risk factors and depression: results from the US National Health and Nutrition Examination Survey.

Background: The comorbidity of cardiovascular disease (CVD) and depression has been well established, as depression usually presents simultaneously with CVD risk factors. However, the potential association between cumulative exposure to CVD risk and depression remains unclear, so we conducted the current investigation. To our knowledge, this is the first study that employs the cumulative risk model to examine the effect of CVD risk factors on depression using nationally representative population and gender, age and CVD status-stratified subpopulations.

Aims: To systematically study the possible individual and cumulative effect of 18 CVD risk factors on depression.

Methods: A cross-sectional, secondary analysis investigated associations between 18 CVD risk factors and depression. The interaction effect between CVD risk factors and age, gender and CVD status was also examined. Enrolment included 20 816 participants from the US National Health and Nutrition Examination Survey 2005-2016. Participants with Patient Health Questionnaire-9 scores over 15 or who were using an antidepressant were considered depressive; 18 known cardiovascular risk factors were incorporated in the present study.

Results: At the individual risk factor level, smoking, drinking, living alone, sleep quality, body mass index, waist circumference and diabetes status had differential associations with depression risk according to the gender, age or CVD status of the participants. Most importantly, gender-stratified cumulative risk analysis indicated that similar depression risk was found in both genders with a small number of CVD risk factors (odds ratio (OR)=1.32; 95% confidence interval (CI): 0.87 to 1.99), but females had a significantly higher depression risk compared with males under high cumulative risk exposure (OR=2.86; 95% CI: 1.79 to 4.59).

Conclusions: Clarifying the association of numerous CVD risk factors with depression according to gender, age and overall CVD status may be beneficial for risk stratification and the prevention of depression in clinical practice. Moreover, the observed novel evidence of high cumulative risk exposure-mediated gender disparities in depression risk may shed light on the underlying mechanism of females' greater vulnerability to depression.