Sex as a moderator of the association between cardiorespiratory fitness and depressive symptoms in older adults.

Higher cardiorespiratory fitness was associated with fewer depressive symptoms in the overall sample of community-dwelling older adults.

• Sample consisted of 648 community-dwelling adults aged 65-80 (mean age [SD] = 69.88 [3.75]).
• 71% of participants were women (n = 461).
• Participants did not have clinical depression, defined as Geriatric Depression Scale score <9.
• The association between CRF and depressive symptoms was β = -0.12, p = .010.
• Analyses adjusted for age, sex, years of education, body mass index, and anxiety symptoms.

Greater amounts of MVPA were associated with fewer depressive symptoms in the overall sample.

• MVPA was assessed using a 7-day actigraphy protocol.
• The association between MVPA and depressive symptoms was β = -0.09, p = .021.
• Depressive symptoms were evaluated using the Hospital Anxiety and Depression Scale.
• Analysis was performed using multiple linear regression.

Greater amounts of light physical activity were associated with fewer depressive symptoms in the overall sample.

• Light PA was assessed using a 7-day actigraphy protocol.
• The association between light PA and depressive symptoms was β = -0.13, p < .001.
• This was the strongest association among the three fitness/activity variables in the overall sample.

Sex moderated the relationship between cardiorespiratory fitness and depressive symptoms, with the association present only in female participants.

• Higher CRF was associated with fewer depressive symptoms only among female participants (β = -0.19, p < .001).
• No significant association between CRF and depressive symptoms was found among male participants.
• This sex moderation effect was identified through moderation analysis included in the multiple linear regression framework.

Sex did not moderate the relationships between light PA or MVPA and depressive symptoms.

• Sex moderation effects were not observed for either light PA or MVPA.
• This contrasts with the significant sex moderation found for CRF.
• The finding suggests that the sex-specific effect is particular to cardiorespiratory fitness rather than to physical activity levels more broadly.

The study sample was composed predominantly of women and excluded individuals with clinical depression.

• 648 community-dwelling adults aged 65-80 were included.
• 71% were women (n = 461); 29% were men.
• Clinical depression was excluded using a Geriatric Depression Scale score cutoff of <9.
• Subsyndromal depressive symptoms were the target outcome, evaluated using the Hospital Anxiety and Depression Scale.
• CRF was assessed using a graded exercise test.