Loss of smell associated with all cause mortality: JAMA

Singapore: The findings of a new study published in the Journal of American Medical Association suggest that olfactory impairment is linked to all-cause mortality and might be a sign of overall health and biological aging.

Olfactory impairment is common and is linked to a variety of comorbidities, including neurodegenerative, cardiovascular, nutritional, and immunological problems. However, epidemiologic links between olfactory impairment and death are contradictory. As a result, Natalie Yan-Lin Pang and colleagues undertook this investigation to rigorously elucidate the epidemiologic correlations between olfactory impairment and mortality.

The databases PubMed, Embase, and the Cochrane Library were searched from their establishment until August 13, 2021. Two blinded reviewers chose observational studies published as full-length English-language articles in peer-reviewed journals that revealed the presence or intensity of chronic olfactory deficits, whether observed directly or self-reported, in association with any mortality assessment in adults aged 18 years or older. Mixed-effects models were used to pool maximally adjusted values, I2 statistics were used to evaluate heterogeneity, meta-regression and subgroup meta-analyses were used to examine causes of heterogeneity, and publication bias was assessed subjectively and quantitatively.