All ETDs from UAB

Advisory Committee Chair

Edmond K Kabagambe

Advisory Committee Members

William L Crosson

Virginia J Howard

Suzanne E Judd

Virginia G Wadley

Document Type

Dissertation

Date of Award

2011

Degree Name by School

Doctor of Philosophy (PhD) School of Public Health

Abstract

Sunlight radiation may be related to stroke risk through increased vitamin D production. The latter has been associated with a number of conditions including stroke, cognitive function and cardiovascular disease. We performed three sets of analyses to determine whether higher levels of sunlight radiation were associated with lower rates of stroke incidence, all-cause mortality, and cognitive decline. We explored these relationships using the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, a national longitudinal cohort of 30,239 participants. We merged the participants' residential histories with a ground and satellite-derived NASA dataset to characterize 15-year average sunlight radiation and maximum ambient air temperature exposures. We then used Cox regression to determine whether sunlight exposure and maximum temperature are associated with stroke incidence and all-cause mortality. We also used logistic regression to determine whether sunlight exposure and temperature are associated with incident cognitive impairment. We performed sensitivity analyses to explore relationships for 10, 5, 2, and 1-year exposure periods. We adjusted for potential confounders and mediators in our analyses. Our results indicated that after adjusting for known risk factors, higher levels of sunlight radiation were associated with lower rates of stroke incidence, but not significantly associated with all-cause mortality. Both more extreme higher and lower average air temperatures were associated with increased rates of stroke incidence and all-cause mortality, with higher temperatures generally having stronger associations in the final models. Higher sunlight radiation was associated with reduced incidence of cognitive impairment, but that the association was stronger and only statistically significant among higher daily maximum air temperatures. In conclusion, we found that increased levels of long-term average sunlight radiation may be beneficial for cerebrovascular health. Long-term extreme higher and lower air temperatures are likely detrimental for cerebrovascular health.

Included in

Public Health Commons

Share

COinS