Age-specific association between thyroid autoimmunity and hypothyroidism in Chinese adults aged over 65 years: a cross-sectional study

Front Endocrinol (Lausanne). 2023 Jul 26:14:1216308. doi: 10.3389/fendo.2023.1216308. eCollection 2023.

Abstract

Background: The correlation between thyroid autoimmune (TAI) disease and hypothyroidism in the elderly of different ages remains unclear. This study aimed to investigate the epidemiological characteristics of hypothyroidism, including subclinical hypothyroidism (Shypo) and overt hypothyroidism (Ohypo) in those aged ≥65 years from iodine-adequate areas and reveal the correlation between TAI and hypothyroidism in the elderly of different ages.

Methods: It was a cross-sectional study involving 2,443 subjects aged ≥65 years from two iodine-adequate areas in China by cluster sampling. They were assigned to the 65-69-, 70-79-, and ≥80-year-old age group. All subjects were surveyed by questionnaires and received physical examinations, laboratory testing, and thyroid ultrasound. Epidemiological characteristics of thyroid diseases in the elderly were compared among the three groups. Risk factors for hypothyroidism were predicted by binary logistic regression analysis.

Results: The median urinary iodine level was 238.70 (197.00, 273.70) μg/L. Thyroid peroxidase antibody or thyroglobulin antibody positivity (11.87%) and Shypo (9.13%) were common in the elderly. The prevalence of hypothyroidism in the elderly increases with age. TAI was a risk factor for Shypo (OR, 1.94; 95% CI, 1.35, 2.80; p < 0.01) and Ohypo (OR, 7.64; 95% CI, 3.40, 17.19; p < 0.01) in elderly Chinese. There was an age-specific correlation between TAI and hypothyroidism in the elderly. However, a significant correlation was not identified between TAI and hypothyroidism in ≥80-year-old age group (p > 0.05).

Conclusion: Hypothyroidism, particularly Shypo, is common in the elderly from iodine-adequate areas in China. TAI serves as a risk factor for hypothyroidism in the elderly, with an age-specific correlation with hypothyroidism.

Keywords: elderly; hypothyroidism; overt hypothyroidism; subclinical hypothyroidism; thyroid autoimmunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Autoimmune Diseases / immunology
  • Autoimmunity*
  • China / epidemiology
  • Cross-Sectional Studies
  • East Asian People
  • Humans
  • Hypothyroidism* / epidemiology
  • Hypothyroidism* / etiology
  • Hypothyroidism* / immunology
  • Iodine / urine
  • Thyroid Diseases / immunology

Substances

  • Iodine

Grants and funding

This study was funded by the Jiangsu Provincial Key R&D Programme (Social Development, BE2020726), the Scientific Research Project of Jiangsu Health Committee (M2020102), the Special Project on Diagnosis and Treatment of Key Clinical Diseases in Suzhou (LCZX201914), the Opening Project of the National Clinical Research Base of Chinese Medicine (JD2019SZXYB13), the Suqian Key Research and Development Program (S202017, S202110), and the Geriatric Health Scientific Research Project of Jiangsu Province (LK2021059).