In the Journals

Poor sense of smell may indicate dementia risk

Jayant M. Pinto

In a cohort of older U.S. adults, individuals with a poor sense of smell had a more than twofold greater likelihood of developing dementia 5 years later when compared with those who had a normal sense of smell, according to recent findings.

“These results show that the sense of smell is closely connected with brain function and health,” study researcher Jayant M. Pinto, MD, of the University of Chicago, said in a press release. “We think a decline in the ability to smell, specifically, but also sensory function more broadly, may be an important early sign, marking people at greater risk for dementia.”

To assess associations between olfactory dysfunction and dementia, researchers conducted a longitudinal study of 2,906 U.S. individuals aged 57 to 85 years. A five-item validated test determined odor identification at baseline. Dementia was reported 5 years later.

When controlling for age, sex, race and ethnicity, education, comorbidities and cognition at baseline, participants with olfactory dysfunction were more than twice as likely to develop dementia 5 years later (OR = 2.13; 95% CI, 1.32-3.43).

Exhibiting more odor identification errors was associated with greater risk for an interval dementia diagnosis (P = .04).

In an accompanying editorial, Stephen Thielke, MD, MSPH, MA, of the Veterans Affairs Medical Center, Puget Sound, Wash., discussed the potential implications of the study’s findings.

“Olfactory dysfunction may be easier to quantify across time than global cognition, which could allow for more systematic or earlier assessment of neurodegenerative changes, but none of this supports that smell testing would be a useful tool for predicting the onset of dementia,” he wrote. – by Amanda Oldt

Disclosures: Pinto reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Jayant M. Pinto

In a cohort of older U.S. adults, individuals with a poor sense of smell had a more than twofold greater likelihood of developing dementia 5 years later when compared with those who had a normal sense of smell, according to recent findings.

“These results show that the sense of smell is closely connected with brain function and health,” study researcher Jayant M. Pinto, MD, of the University of Chicago, said in a press release. “We think a decline in the ability to smell, specifically, but also sensory function more broadly, may be an important early sign, marking people at greater risk for dementia.”

To assess associations between olfactory dysfunction and dementia, researchers conducted a longitudinal study of 2,906 U.S. individuals aged 57 to 85 years. A five-item validated test determined odor identification at baseline. Dementia was reported 5 years later.

When controlling for age, sex, race and ethnicity, education, comorbidities and cognition at baseline, participants with olfactory dysfunction were more than twice as likely to develop dementia 5 years later (OR = 2.13; 95% CI, 1.32-3.43).

Exhibiting more odor identification errors was associated with greater risk for an interval dementia diagnosis (P = .04).

In an accompanying editorial, Stephen Thielke, MD, MSPH, MA, of the Veterans Affairs Medical Center, Puget Sound, Wash., discussed the potential implications of the study’s findings.

“Olfactory dysfunction may be easier to quantify across time than global cognition, which could allow for more systematic or earlier assessment of neurodegenerative changes, but none of this supports that smell testing would be a useful tool for predicting the onset of dementia,” he wrote. – by Amanda Oldt

Disclosures: Pinto reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.