A low level of physical activity (<35 MET-hours/week) was associated with increased mortality (HR 1.50; 95% CI 1.20-1.88), dementia, and depressive symptoms among older Mexican Americans.
Cohort
Does a low level of physical activity increase the risk of mortality, dementia, and depressive symptoms in older Mexican Americans?
Low physical activity increases the risk of mortality, dementia, and depression in older Mexican Americans, with inflammation partially mediating the effects on mortality and cognition.
Hazard Ratio: 1.5 (95% CI 1.2–1.88)
A higher level of physical activity (PA) is associated with decreased risk of mortality, dementia, and depression, yet the mechanisms involved are not well understood, and little evidence exists for Mexican Americans. With data from the Sacramento Area Latino Study on Aging (1998-2007), we used Cox proportional hazards regression to separately evaluate associations of baseline PA level with mortality, dementia/cognitive impairment without dementia (CIND), and depressive symptoms, and we estimated the mediating effects of inflammatory markers in additive hazard models. A low level of PA (<35 metabolic equivalent of task-hours/week) was associated with increased mortality (hazard ratio (HR) = 1.50, 95% confidence interval (CI): 1.20, 1.88), dementia/CIND (HR = 1.37, 95% CI: 0.96, 1.96), and depressive symptoms (HR = 1.23, 95% CI: 1.00, 1.52). A low PA level added 512 (95% CI: -34, 1,058) cases of dementia/CIND per 100,000 person-years at risk (direct effect), while, through a mediating path, interleukin 6 (IL-6) added another 49 (95% CI: 5, 94) cases, or 9% of the total effect. For mortality, 8%-10% of the PA total effect was mediated through IL-6, tumor necrosis factor α (TNF-α), or TNF-α receptors. None of the inflammatory markers mediated the association between PA and depressive symptoms. Our results suggest that antiinflammation (especially as assessed by IL-6 and TNF-α levels) may partly explain how PA protects against dementia/CIND and mortality.
Shih et al. (Tue,) conducted a cohort in Older Mexican Americans. Low level of physical activity (<35 metabolic equivalent of task-hours/week) vs. Higher level of physical activity was evaluated on Mortality (HR 1.50, 95% CI 1.20, 1.88). A low level of physical activity (<35 MET-hours/week) was associated with increased mortality (HR 1.50; 95% CI 1.20-1.88), dementia, and depressive symptoms among older Mexican Americans.