Effect of thyroid hormone replacement treatment on cardiac diastolic function in adult patients with subclinical hypothyroidism: a meta-analysis

Front Endocrinol (Lausanne). 2023 Sep 25:14:1263861. doi: 10.3389/fendo.2023.1263861. eCollection 2023.

Abstract

Background: Although subclinical hypothyroidism (SCH) is related to abnormalities in left ventricular diastolic function, the use of levothyroxine as a regular treatment remains debatable. This meta-analysis aimed to determine whether thyroid hormone replacement therapy affects cardiac diastolic function in patients with SCH as measured by echocardiography.

Methods: This meta-analysis included a search of the EMBASE, PubMed, Web of Science, and Cochrane Library databases from their inception to May 18, 2023, for studies analyzing cardiac morphology and functional changes in patients with SCH before and after thyroid hormone replacement. The outcome measures were cardiac morphology and diastolic and overall cardiac function, as assessed using ultrasound parameters (including ventricular wall thickness, chamber size, mitral wave flow, tissue Doppler, and speckle tracking). The quality of the studies was assessed using the Newcastle-Ottawa Scale. The standard mean differences (MDs) and 95% confidence intervals (CI) were calculated using fixed- or random-effects models.

Results: Seventeen studies met the inclusion criteria. A total of 568 patients participated and completed the follow-up. All studies specifically stated that serum thyrotropin levels returned to normal by the end of the study period. Compared with baseline levels, no significant morphological changes were observed in the heart. In terms of diastolic function, we discovered that the ratios of E-velocity to A-velocity (E/A) had greatly improved after thyroid hormone replacement therapy, whereas the ratios of the mitral inflow E wave to the tissue Doppler e' wave (E/e') had not. Global longitudinal strain (GLS) increased significantly after treatment with levothyroxine.

Conclusion: In adult patients with SCH, thyroid hormone supplementation can partially but not completely improve parameters of diastolic function during the observation period. This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement, an updated guideline for reporting systematic reviews (11) and was registered with INPLASY (INPLASY202320083).

Systematic review registration: https://inplasy.com/inplasy-2023-2-0083.

Keywords: diastolic function; echocardiography; levothyroxine; meta-analysis; subclinical hypothyroidism.

Publication types

  • Meta-Analysis
  • Systematic Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Diastole
  • Echocardiography
  • Hormone Replacement Therapy*
  • Humans
  • Hypothyroidism* / complications
  • Hypothyroidism* / diagnosis
  • Hypothyroidism* / drug therapy
  • Thyroxine* / therapeutic use
  • Ventricular Function, Left

Substances

  • Thyroxine

Grants and funding

The authors declare financial support was received for the research, authorship, and/or publication of this article. This work is supported by Intra hospital fund of the First Hospital of Lanzhou University [grant number ldyyyn2022-58]; Gansu Health Industry Scientific Research Project [grant number GSWSKY2022-67]; Science and Technology Project of Gansu Province [grant number 21JR11RA090]; Gansu Province Administration of Traditional Chinese Medicine [grant number GZKG-2022-54].