Interrelationship between physical activity, symptomatology of upper respiratory tract infections, and depression in...

It has been suggested that regular moderate physical activity (PA) promotes resistance to upper respiratory tract infections (URTI). In an older population, this relationship should be examined in a wider concept of multiple factors potentially able to influence infection rate and reported symptomatology. Especially, the impact of depression should be taken into consideration.

To examine the association of URTI with PA and depressive symptoms in the elderly, and whether this relationship persists after controlling for confounders attributable to comorbidities, functional status, and cognitive function.

One hundred and forty-five subjects (80 women and 65 men) between 66 and 79 years of age were randomly chosen from all inhabitants of one district of the city of Lodz (Poland). They participated in baseline and 1-year follow-up examinations and completed the infection questionnaire during the whole year. Log books for daily recording of the URTI symptomatology were used in the prospective design. The PA was assessed by the Seven-Day Physical Activity Recall Questionnaire. Geriatric Depression Scale and other elements of the comprehensive geriatric assessment were also used.

In bivariate relationships, the number of episodes per year and the number of days with URTI per year were significantly negatively associated with several baseline and follow-up PA indices and directly related to baseline and follow-up depression scores. In multivariate relationships, after controlling for other elements of the comprehensive geriatric assessment, both PA and depression contributed to URTI symptomatology, while URTI symptoms predicted final PA scores, and changes in PA added to the follow-up depression score.

These results indicate that in elderly subjects the symptomatology of URTI is interrelated with their habitual PA and depressive symptomatology. Less active and more depressed subjects develop more URTI symptoms during 1-year follow-up. This URTI symptomatology, together with the baseline PA and the depressive status, contributes to the follow-up PA and depression scores.