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Altitude may impact Alzheimer dementia mortality

Higher altitude was associated with a lower mortality rate for Alzheimer dementia, according to study findings in JAMA Psychiatry.

“Environmental risk factors for Alzheimer dementia are not well understood. Air pollution may have a causative role,” according to Stephen Thielke, MD, MS, MA, of Puget Sound VA Medical Center, Seattle, and colleagues.

To determine whether rates of dementia were associated with average altitude of residence, researchers analyzed county-specific deaths attributed to Alzheimer dementia reported within a single statewide public health system over 1 year in California.

Researchers found an approximate 2-point decline in the age-adjusted mortality rate for dementia for each doubling of altitude, according to age-adjusted models.

The predicted rate for the highest county, at 1,800 meters, was 14 points lower than the lowest county at 15 meters.

Researchers found similar results for counties that had more than 15 deaths attributed to dementia.

“This analysis suggests that altitude of residence may impact the risk for dying of Alzheimer dementia. Ecologic studies of this type must be interpreted cautiously. Unexamined factors may account for differential reporting of cases across counties, including miscategorization of other forms of dementia,” Thielke and colleagues wrote. “Additional work is needed to determine whether this relationship holds in other populations.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.