Hypothyroidism, Sex, and Age Predict Future Thromboembolic Events Among Younger People

Association between thyroid dysfunction and venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Thyroid dysfunction plays an important role in the development of cardiovascular disease. However, its relationship with venous thromboembolism (VTE) remains unclear. We performed a meta-analysis of published cohort and case-control studies to investigate the association between thyroid dysfunction and VTE comprehensively.

METHODS

Three reviewers independently searched EMbase, PubMed, China national knowledge infrastructure, and Cochrane Library databases for relevant articles from the time of database establishment to 01 October 2022 and identified all studies on thyroid dysfunction and VTE as studies of interest. Of the 2418 publications retrieved, we identified 10 articles with 15 studies that met our selection criteria. Pooled ORs and 95% confidence intervals were calculated using fixed- or random-effect models.

RESULTS

We pooled 8 studies by a fixed-effect model, which suggested an increased risk of VTE in patients with (subclinical) hyperthyroidism (OR 1.33, 95% CI: 1.29-1.38). In the other 7 studies on patients with (subclinical) hypothyroidism, the risk was similarly increased when pooled by a random-effect model (OR 1.52, 95% CI: 1.23-1.89). After sensitivity analysis and risk of bias analysis, the risk of VTE was still increased in both (subclinical) hyperthyroidism (OR 1.322, 95% CI: 1.278-1.368) and (subclinical) hypothyroidism (OR 1.74, 95% CI: 1.41-2.16).

CONCLUSION

Patients with thyroid dysfunction have an increased risk of VTE. Therefore, it is recommended to perform thyroid function screening routinely in patients at high risk of VTE.

Expression patterns of serum MicroRNAs related to endothelial dysfunction in patients with subclinical hypothyroidism

BACKGROUND

Increasing evidence has shown that elevated Thyroid stimulating hormone (TSH) levels are positively correlated with atherosclerosis (ATH) in patients with subclinical hypothyroidism (SCH). Some researchers found that the dysfunction of Endothelial Cells (ECs) in SCH plays an important role in the pathogenesis of ATH in SCH, but the association remains controversial.

OBJECTIVES

To determine the expression profiles of serum microRNAs critical to the function of Endothelial cells (ECs) may help reanalyze the possible mechanism underlying ATH in SCH and the association between ATH and SCH.

METHODS

We used qRT-PCR to perform microRNA profiling and analysis in normal control subjects (NC), patients with SCH alone (SCH), patients with SCH and ATH (SCH+ATH), and patients with ATH without SCH (ATH).

RESULTS

Both miR-221-3p and miR-222-3p showed a decreasing expression trend between the SCH and SCH+ATH groups. In addition, miR-126-3p and miR-150-5p showed a stepwise decrease from the NC to SCH groups and then to the SCH+ATH or ATH group. miR-21-5p was unregulated in the SCH, SCH+ATH, and ATH groups. Furthermore, elevated levels of miR-21-5p in SCH+ATH group were higher than SCH and ATH group. No differences were found in the levels of miR-150, miR-126, miR-221 and miR-222 between the ATH and the SCH+ATH subjects.

CONCLUSIONS

miR-21-5p may be involved in the atherosclerosis process in patients with SCH (SCH and SCH+ATH groups). miR-150-5p may be sensitive risk markers for predicting endothelial dysfunction in patients with ATH (ATH and SCH+ATH groups).

Thyroid Hormone Therapy and Incident Stroke

CONTEXT

Stroke is a leading cause of death and disability and there is a need to identify modifiable risk factors.

OBJECTIVE

We aimed to determine the relationship between thyroid hormone treatment intensity and incidence of atrial fibrillation and stroke.

METHODS

We conducted a retrospective cohort study using data from the Veterans Health Administration between 2004 and 2017, with a median follow-up of 59 months. The study population comprised 733 208 thyroid hormone users aged ≥18 years with at least 2 thyroid stimulating hormone (TSH) measurements between thyroid hormone initiation and incident event (atrial fibrillation or stroke) or study conclusion (406 030 thyroid hormone users with at least 2 free thyroxine [T4] measurements).

RESULTS

Overall, 71 333/643 687 (11.08%) participants developed incident atrial fibrillation and 41 931/663 809 (6.32%) stroke. In multivariable analyses controlling for pertinent factors such as age, sex, and prior history of atrial fibrillation, higher incidence of stroke was associated with low TSH or high free T4 levels (ie, exogenous hyperthyroidism; eg, TSH <0.1 mIU/L; OR 1.33; 95% CI, 1.24-1.43; free T4>1.9 ng/dL, OR 1.17, 95% CI 1.06-1.30) and high TSH or low free T4 levels (ie, exogenous hypothyroidism; eg, TSH >5.5 mIU/L; OR 1.29; 95% CI, 1.26-1.33; free T4 <0.7 ng/dL; OR 1.29; 95% CI, 1.22-1.35) compared with euthyroidism (TSH >0.5-5.5 mIU/L and free T4 0.7-1.9 ng/dL). Risk of developing atrial fibrillation and stroke was cumulative over time for both patients with exogenous hyperthyroidism and hypothyroidism.

CONCLUSION

Both exogenous hyper- and hypothyroidism were associated with increased risk of stroke, highlighting the importance of patient medication safety.

Association between SSNHL and Thyroid Diseases

The association between thyroid disease and sudden sensorineural hearing loss (SSNHL) has not been evaluated. We investigated the association of goiter, hypothyroidism, thyroiditis, and hyperthyroidism with sudden sensorineural hearing loss (SSNHL). Data from the Korean National Health Insurance Service-Health Screening Cohort were used. The 8658 SSNHL patients were matched in a 1:4 ratio with 34,632 controls for age, sex, and region of residence. Histories of goiter, hypothyroidism, thyroiditis, hyperthyroidism, and Levothyroxine medication were explored as possible factors influencing SSNHL development. Associations were estimated using conditional logistic regression analyses, adjusted for Levothyroxine medication use. Subgroup analyses were conducted according to age, sex, income, and region of residence. SSNHL patients had a higher rate of goiter occurrence (4.4% vs. 3.7 %, p = 0.001) and hypothyroidism (4.0% vs. 3.2 %, p < 0.001) than controls. Goiter and hypothyroidism were positively associated with SSNHL (adjusted OR =1.14 (95% CI =1.01–1.28), p = 0.043 for goiter and 1.17 (95% CI =1.03–1.33), p = 0.016 for hypothyroidism). In subgroup analyses, hypothyroidism or goiter was more prevalent in SSNHL patients than in controls. Lower-income subgroups showed associations of hypothyroidism and goiter with SSNHL. SSNHL patients were more likely to have goiter and hypothyroidism than normal individuals.

Hypothyroidism, Sex, and Age Predict Future Thromboembolic Events Among Younger People

PURPOSE

Aberrant thyroid function causes dysregulated metabolic homeostasis. Literature has demonstrated hypercoagulability in hypothyroidism, suggesting a risk for thromboembolic events (TEE). We hypothesize that individuals with hypothyroidism will experience more clinically-diagnosed TEE than euthyroid individuals.

METHODS

De-identified patient data from the University of New Mexico Health Sciences Center were retrieved using thyrotropin (TSH; thyroid-stimulating hormone) for case-finding from 2005 to 2007 and ICD billing codes to identify TEE during the follow-up period of 10 to 12 years. Diagnoses affecting coagulation were excluded and 12 109 unique enrollees were categorized according to TSH concentration as Hyperthyroid (n = 510), Euthyroid (n = 9867), Subclinical Hypothyroid (n = 1405), or Overtly Hypothyroid (n = 327). Analysis with multiple logistic regression provided the odds of TEE while adjusting for covariates.

RESULTS

There were 228 TEEs in the cohort over 5.1 ± 4.3 years of follow-up. Risk of TEE varied significantly across study groups while adjusting for sex, race/ethnicity, levothyroxine, oral contraceptive therapy, and visit status (outpatient vs non-outpatient), and this risk was modified by age. Overt Hypothyroidism conferred a significantly higher risk of TEE than Euthyroidism below age 35, and Hyperthyroidism conferred an increased risk for TEE at age 20. Analysis also demonstrated a higher age-controlled risk for a subsequent TEE in men compared with women (odds ratio [OR] = 1.36; 95% confidence interval [CI], 1.02-1.81). Subanalysis of smoking status (n = 5068, 86 TEE) demonstrated that smokers have 2.21-fold higher odds of TEE relative to nonsmokers (95% CI, 1.41-3.45).

CONCLUSIONS

In this retrospective cohort study, Overt Hypothyroidism conferred increased risk of TEE over the next decade for individuals younger than 35 years of age, as compared with Euthyroidism.