Thyroid antibodies, autoimmunity and cognitive decline: is there a population-based link?

Kate Napthali; Michael Boyle; Huy Tran; Peter W Schofield; Roseanne Peel; Mark McEvoy; Christopher Oldmeadow; John Attia

doi:10.1159/000362716

Thyroid antibodies, autoimmunity and cognitive decline: is there a population-based link?

Dement Geriatr Cogn Dis Extra. 2014 May 21;4(2):140-6. doi: 10.1159/000362716. eCollection 2014 May.

Authors

Kate Napthali¹, Michael Boyle¹, Huy Tran², Peter W Schofield³, Roseanne Peel⁴, Mark McEvoy⁴, Christopher Oldmeadow⁴, John Attia⁵

Affiliations

¹ Division of Medicine, John Hunter Hospital, University of Newcastle, Newcastle, N.S.W., Australia.
² Hunter Area Pathology Service, Newcastle, N.S.W., Australia.
³ Centre for Brain and Mental Health Research, University of Newcastle, Newcastle, N.S.W., Australia ; Hunter Medical Research Institute, University of Newcastle, Newcastle, N.S.W., Australia ; Neuropsychiatry Unit, Hunter New England Local Health District, Newcastle, N.S.W., Australia.
⁴ Hunter Medical Research Institute, University of Newcastle, Newcastle, N.S.W., Australia ; Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, Newcastle, N.S.W., Australia.
⁵ Division of Medicine, John Hunter Hospital, University of Newcastle, Newcastle, N.S.W., Australia ; Hunter Medical Research Institute, University of Newcastle, Newcastle, N.S.W., Australia ; Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, Newcastle, N.S.W., Australia.

Abstract

Background: Autoimmunity is considered an uncommon but under-recognised cause of cognitive decline.

Methods: Serum samples from 3,253 randomly selected subjects enrolled in the Hunter Community Study, aged 55-85 years, were assayed for thyrotropin stimulatory hormone, anti-thyroid peroxidase antibodies (TPO-Ab), anti-nuclear antibodies (ANA) and extractable nuclear antigens (ENA). Cognitive function was assessed using the Audio Recorded Cognitive Screen (ARCS) tool.

Results: TPO-Ab were found in 8.4% and ANA in 27.9% of the study population, of whom 3% had positive ENA findings. No relationship was found between the ARCS score and either TPO-Ab (coefficient = 0.133; 95% CI -0.20, 0.82, p = 0.616), ANA at a low (coefficient = 1.01; 95% CI -2.58, 0.55, p = 0.203) or a high titre (coefficient = -0.65; 95% CI -2.59, 1.28, p = 0.508), or ENA antibodies (coefficient = 5.12; 95% CI -0.53, 10.77; p = 0.076).

Conclusions: Autoantibody findings are common in an aging population and are not associated with cognitive decline.

Keywords: Anti-nuclear antibodies; Autoantibodies; Autoimmune thyroiditis; Dementia; Encephalitis; Hashimoto disease; Mild cognitive impairment; Nuclear antigens.