Association between thyroid dysfunction and insulin resistance: a retrospective cohort study

BMJ Open. 2025 Jan 6;15(1):e076397. doi: 10.1136/bmjopen-2023-076397.

Abstract

Objective: To evaluate the association between thyroid disease and diabetes markers.

Design: Retrospective cohort study.

Setting: The study was conducted in a diagnostic setting where the primary care providers recommended the patients to test for thyroid and diabetes panels.

Participants: The thyroid and diabetes markers were tested in 32 787 subjects with suspected thyroid and related conditions who visited Vibrant America Clinical Laboratory between January 2015 and June 2019.

Results: Our general prevalence results showed that homeostatic model assessment-insulin resistance (HOMA-IR) was elevated in overt hypothyroid subjects (43.7%) and overt hyperthyroid subjects (42.2%). Glycated hemoglobin (HbA1C) was elevated in subclinical hypothyroid subjects (19.2%), overt hypothyroid subjects (22.3%) and overt hyperthyroid subjects (21.2%). Glucose was significantly elevated in subclinical hypothyroid subjects (24.2%) and overt hyperthyroid subjects (31.0%). Insulin was significantly elevated in overt hypothyroid subjects (15.1%). Interestingly, we found that 70.3% of subjects who had their HOMA-IR score escalated from negative (HOMA-IR<2.7) to positive (HOMA-IR>2.7) during their multiple visits had anti-thyroid peroxidase (anti-TPO) 369 (±242) days prior to the onset of this change.

Conclusion: Our findings showed that anti-TPO levels are elevated before the onset of insulin resistance, indicating its potential use as a predictive marker.

Keywords: DIABETES & ENDOCRINOLOGY; General endocrinology; Thyroid disease.

MeSH terms

  • Adult
  • Aged
  • Autoantibodies / blood
  • Biomarkers / blood
  • Blood Glucose / analysis
  • Blood Glucose / metabolism
  • Female
  • Glycated Hemoglobin* / analysis
  • Glycated Hemoglobin* / metabolism
  • Humans
  • Hyperthyroidism / blood
  • Hyperthyroidism / complications
  • Hypothyroidism* / blood
  • Hypothyroidism* / epidemiology
  • Insulin / blood
  • Insulin Resistance*
  • Iodide Peroxidase / immunology
  • Male
  • Middle Aged
  • Retrospective Studies
  • Thyroid Diseases / blood
  • Thyroid Diseases / complications
  • Thyroid Diseases / epidemiology

Substances

  • Glycated Hemoglobin
  • Blood Glucose
  • Biomarkers
  • Insulin
  • Iodide Peroxidase
  • Autoantibodies