Table 5.

Association between Neuroimaging Biomarkers and impaired odor identification (outcome variable) in cognitively normal individuals - the Mayo Clinic Study of Aging.

	Impaired Olfaction						Continuous B-SIT
	Anosmia vs. normosmiaa			Hyposmia vs. normosmiaa
Imaging Biomarkers	Abn /All	OR (95%CI)b	p	Abn /All	OR (95%CI)	p	slope (95%CI)c	p
A+/N− vs. A−/N−d	14/85	1.13 (.33, 3.81)	.85	105/176	.97 (.51,1.85)	.92	.14 (−.49, .77)	.66
A−/N+ vs. A−/N−	11/80	.40 (.09, 1.78)	.23	104/173	.87 (.43, 1.73)	.68	.26 (−.41, .94)	.44
A+/N+ vs. A−/N−	19/75	3.84 (1.14, 12.97)	.03	99/155	1.91 (.80, 4.54)	.14	−.99 (−1.71, −.27)	<.01

^aOsmia categories were defined as follows: anosmia (score <6), hyposmia (men 6–10, women 6–10.25), normosmia (men 10.25–12; women 10.5–12); B-SIT score was calculated as the sum of the correct responses for persons with ≤2 missing responses.

^bOdds ratio (95% confidence interval) reported for anosmia vs. normosmia and hyposmia vs. normosmia were retained from a single multinomial logistic regression model, having osmia as the dependent variable and adjusted for age (at B-SIT testing), education, sex.

^cSlopes (95% CI) retained from a single multivariable linear regression model, adjusted for age (at B-SIT testing), education, sex.

^dImaging biomarker groups defined by the combination of abnormality for amyloid (A+/A−) and neurodegeneration (N+/N−); A+, is defined as ¹¹C-PIB standardized uptake value ratio (SUVR)>1.40 and A− if otherwise; and N+ is defined as either HVa <−2·40 cm³ or FDG <1.32 SUVR and N− if otherwise.

B-SIT = Brief Smell Identification Test; Abn. - the number of persons with abnormal B-SIT; All - participants with and without abnormal biomarkers in the specific analysis strata; OR – odds ratio; CI – confidence interval.