Autoimmune thyroiditis associated with mild "subclinical" hypothyroidism in adults with Down syndrome: a comparison of patients with and without manifestations of Alzheimer disease

Topic: Brain proteins, microglia and lab models

Serum tests of thyroid function were compared in Down syndrome (DS) patients with and without manifestations of Alzheimer disease (AD). Relative to control individuals, DS patients had, overall, lower mean total T4 (P = 0.070) and T3f (P = 0.015), higher T3U (P = 0.013) and TSH (P = 0.020), no difference in free T4, and higher thyroid antithyroglobulin (ATA) (P = 0.033) and antimicrosomal autoantibody (AMA) titres (P = 0.0097). Similar trends were apparent in DS males and females, and in DS patients off all drugs. In an analysis of case/control pairs with corrections for age and sex, DS patients with AD manifestations (n = 9) had significantly lower T3 (P = 0.029) and higher AMA (P = 0.043) than paired control individuals, whereas DS patients without AD manifestations (n = 20) had significantly lower T3 (P = 0.013) but higher ATA (P = 0.0065). T3 was significantly lower in the DS patients with AD manifestations than in the unaffected (P = 0.0013). These data suggest that autoimmune thyroiditis associated with a mild "subclinical" form of hypothyroidism is common in adult DS patients and more pronounced in patients with AD manifestations than in those without. This "subclinical" hypothyroidism may contribute to cognitive deficits in ageing DS patients.

Key findings

• Relative to control individuals, DS patients had, overall, lower mean total T4 (P = 0.070) and T3f (P = 0.015), higher T3U (P = 0.013) and TSH (P = 0.020), no difference in free T4, and higher thyroid antithyroglobulin (ATA) (P = 0.033) and antimicrosomal autoantibody (AMA) titres (P = 0.0097).
• In an analysis of case/control pairs with corrections for age and sex, DS patients with AD manifestations (n = 9) had significantly lower T3 (P = 0.029) and higher AMA (P = 0.043) than paired control individuals, whereas DS patients without AD manifestations (n = 20) had significantly lower T3 (P = 0.013) but higher ATA (P = 0.0065).
• T3 was significantly lower in the DS patients with AD manifestations than in the unaffected (P = 0.0013).
• These data suggest that autoimmune thyroiditis associated with a mild "subclinical" form of hypothyroidism is common in adult DS patients and more pronounced in patients with AD manifestations than in those without.

Why it matters

This study found that adults with Down syndrome often had autoimmune thyroiditis with mild subclinical hypothyroidism, and this was more pronounced in those with Alzheimer's disease symptoms. The authors suggest this mild hypothyroidism may contribute to cognitive deficits, but no treatment trial was conducted.

Study details

• Evidence strengthLow

Read the original

• DOI: 10.1002/ajmg.1320360205
• PubMed: 2142381
• Original source →

May need a subscription OpenAlex found no free copy of the full text (checked 6 Feb 1020), so the publisher may charge for it. The PubMed abstract is free.

@article{percy1990-2142381,
  author  = {Percy, M. E. and Dalton, A. J. and Markovic, V. D. and Crapper McLachlan, D. R. and Gera, E. and Hummel, J. T. and Rusk, A. C. and Somerville, M. J. and others},
  title   = {{Autoimmune thyroiditis associated with mild "subclinical" hypothyroidism in adults with Down syndrome: a comparison of patients with and without manifestations of Alzheimer disease}},
  journal = {American journal of medical genetics},
  year    = {1990},
  doi     = {10.1002/ajmg.1320360205},
  pmid    = {2142381},
  url     = {https://doi.org/10.1002/ajmg.1320360205}
}

Studies this one cites

Referenced by this study and also in the alzhub library, so you can read them here.

• Alzheimer's disease in Down's syndrome: clinicopathologic studies Neurology · 1985-07-01 · usefulness score 61/100 · Getting a diagnosis
• Red cell superoxide dismutase, glutathione peroxidase and catalase in Down syndrome patients with and without manifestations of Alzheimer disease American journal of medical genetics · 1990-04-01 · usefulness score 38/100 · Down syndrome and Alzheimer's
• Alzheimer degeneration in Down syndrome. Electrophysiologic alterations and histopathologic findings Archives of neurology · 1975-09-01 · usefulness score 37/100 · Down syndrome and Alzheimer's

Later studies that cite this one

4 studies in the alzhub library list this one in their references.

• Association between Hypothyroidism Onset and Alzheimer Disease Onset in Adults with Down Syndrome Brain sciences · 2021-09-16 · usefulness score 46/100 · Down syndrome and Alzheimer's
• Relation between apolipoprotein E genotype, hepatitis B virus status, and thyroid status in a sample of older persons with Down syndrome American journal of medical genetics. Part A · 2003-07-01 · usefulness score 40/100 · Down syndrome and Alzheimer's
• Thyroid stimulating hormone-receptor overexpression in brain of patients with Down syndrome and Alzheimer's disease Life sciences · 1999-01-01 · usefulness score 36/100 · Down syndrome and Alzheimer's
• Immunoglobulin G subclasses in older persons with Down syndrome Journal of the neurological sciences · 1993-07-01 · usefulness score 35/100 · Down syndrome and Alzheimer's

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