Is routine measurement of TSH in hospitalized patients necessary?

The Spectrum of Thyroid Function Tests and Autoantibodies During Hospitalization and After Six Months of Discharge in COVID-19 Patients: Does COVID-19 Trigger Autoimmunity?

OBJECTIVE

The aim of the study was to investigate thyroid function test (TFT) results and anti-thyroid antibody titers in acutely infected COVID-19 patients, as well as the changes in TFT and autoantibody results during the 6-months recovery period among survivors.

PATIENTS AND DESIGN

A total of 163 adult COVID-19 patients and 124 COVID-19 survivors were evaluated in terms of TFT (thyroid stimulating hormone [TSH], free triiodothyronine [fT3], and free thyroxine [fT4]) and anti-thyroid antibodies (anti-thyroglobulin [anti-Tg] and anti-thyroid peroxidase [anti-TPO]).

RESULTS

Thyroid dysfunction was noted in 56.4% of patients on admission, including the non-thyroidal illness syndrome (NTIS) in most cases. Presence vs. absence of thyroid dysfunction on admission was associated with significantly higher rate of severe disease (p < 0.001), while severe vs. mild-to-moderate disease was associated with significantly lower serum fT3 levels (p = 0.001). Overall, 94.4% of survivors were euthyroid at the time of 6 months post-discharge, while in some patients, the post-COVID-19 recovery period was also associated with significantly increased anti-TPO titers and the presence of new-onset or persistent subclinical hypothyroidism.

CONCLUSION

This is one of the few studies to evaluate TFT and autoantibodies over a 6-month period after recovery from COVID-19. The presence of emergent or persistent subclinical hypothyroidism and the significantly increased anti-TPO titers in some patients during the convalescence period suggest the need for follow-up for development of thyroid dysfunction and autoimmunity among COVID-19 survivors.

Indications for ordering thyroid-stimulating hormone in noncritically ill adult inpatients-A Delphi consensus recommendation

BACKGROUND

Thyroid-stimulating hormone (TSH) is ordered commonly among inpatients, but the possibility of nonthyroidal illness syndrome challenges interpretation.

OBJECTIVE

Our objective was to obtain Canadian consensus on appropriate indications for ordering TSH in the first 48 h following presentation of a noncritically ill internal medicine patient.

DESIGN, SETTING AND PARTICIPANTS

Canadian endocrinologists with inpatient expertise were invited via snowball sampling to an online 3-round Delphi study. Main Outcome and Measures using a 6-point Likert scale, they rated 58 indications on appropriateness for measuring TSH in medical inpatients. These indications included clinical presentations, signs, and symptoms. Items that reached consensus and agreement (≥80% of participants selecting a rating of 5 or 6 on the Likert scale) were tabulated and dropped after each round. Qualitative analysis of comments identified additional contextual considerations as themes.

RESULTS

There were 45 participants (academic setting: 84%) representing 8 provinces (Ontario: 64%). Rounds 2 and 3 were completed by 42 and 33 participants, respectively. Nine indications reached consensus and agreement: presumed myxedema coma, presumed thyroid storm, atrial fibrillation/flutter, euvolemic hyponatremia, proptosis, adrenal insufficiency, hypothermia, thyroid medication noncompliance, and goiter. There was also agreement that two contextual considerations identified in thematic analysis, including a recent abnormal outpatient TSH, and the presence of other findings of thyroid dysfunction, would significantly change some mid-range responses.

CONCLUSIONS

Canadian experts agreed upon nine specific indications for ordering an inpatient TSH, with others requiring consideration of previous TSH measurement and clinical context.

Subclinical hypothyroidism or isolated high TSH in hospitalized patients with chronic heart-failure and chronic renal-failure

Sub-clinical hypothyroidism (SCH) is common in heart failure (HF) and advanced renal failure (RF), but it is unclear whether there is a thyroid disease or a transient increase in TSH level. This is a retrospective study of hospitalized patients in medical departments. All patients with SCH and a TSH level up to less than 12 mIU/L were identified. Those who had at least one recurring admission within at least 6 months were included. A change in thyroid function during the last re-admission was determined and classified as an improvement, no change, or worsening of thyroid function. Overall, 126 cases of SCH met the inclusion criteria for re-admission. Analysis of the most recent hospitalization showed that in 100 (79.4%) patients thyroid function improved, in 15 (11.9%) patients thyroid function remained unchanged and only in 11 (8.7%) patients did thyroid function worsen. In most cases, worsening of hypothyroidism was determined by initiation of a low dose levothyroxine treatment. Of the 126 participants, 43 (34.1%) and 22 (17.5%) had a diagnosis of HF and RF (CKD stages 4 and 5), respectively. There was no association between HF or advanced RF and worsening of SCH. No association was found between worsening of hypothyroidism and gender, age, TSH, or creatinine levels in the first hospitalization. A borderline association between elevated CRP levels at first hospitalization and hypothyroidism worsening was found (p = 0.066). Mildly elevated TSH in hospitalized patients with HF and advanced RF is transient and most probably not related to thyroid disease and not associated with age or gender.

The significance of high thyroxine in hospitalized patients with low thyroid-stimulating hormone

PURPOSE

There is scarce data about the interpretation of high thyroid hormone levels in hospitalized patients. We wished to investigate the significance of high thyroxine (T4) in hospitalized patients with low TSH.

METHODS

We conducted a retrospective study of data from patients in nonsurgical departments. Three groups of random patients with low TSH were defined and compared: 123 patients with only high FT4 levels (T4 group), 82 with high FT3 levels with or without high FT4 level (T3 group), and 119 with low FT3 and FT4 level in the lower half of the norm and below (NTIS group).

RESULTS

The primary cause of admission in the T4 and NTIS groups was infectious disease, 20.3% and 40.3%, respectively; while in the T3 group it was cardiovascular disease (31.7%). The T4 group but not T3 group had epidemiological and clinical characteristics similar to the NTIS group. The T4 group had a significant correlation between increased CRP levels and decreased FT3 (r = 0.366, p < 0.001) similar to the NTIS group. The T3 group had a borderline correlation between increased FT3 and FT4 levels (r = 0.208, p = 0.061) but the T4 group did not.

CONCLUSIONS

The combination of low TSH and high FT4 levels in hospitalized patient is usually caused by nonthyroidal illness combined with drug effects. This thyroid function disturbance is common in hospitalized patients and if the FT3 level is below the middle of the norm, treatment is probably unnecessary.

Intravenous levothyroxine stewardship program at a tertiary academic medical center

PURPOSE

Based on the pharmacokinetic profile of levothyroxine, a 3-day hold guideline for adult patients ordered for intravenous (IV) levothyroxine was implemented at a tertiary academic medical center. The purpose of this study was to evaluate the impact of the implementation of an IV levothyroxine hold guideline.

METHODS

This single-center, retrospective analysis identified patients ordered for IV levothyroxine during a 13-week period before and after implementation of the guideline. The primary outcome was guideline adherence, defined as full implementation of the 3-day hold. Secondary outcomes included the number of IV levothyroxine administrations avoided in the post-guideline group, extrapolated yearly cost avoidance (EYCA) after guideline implementation, reasons for guideline non-adherence, and number of safety reports involving IV levothyroxine.

RESULTS

A total of 166 and 134 patients met inclusion criteria for the pre- and post-guideline groups, respectively. Guideline adherence was observed in 94 (70.1%) patients, resulting in 276 vials saved in the 13-week post-guideline period, which translated to an EYCA of $139,877. Forty orders (29.9%) were non-adherent to the guideline, with the most common reason stated as nil per os (NPO). No difference in safety outcomes was seen between the pre- and post-guideline groups, as evidenced by 1 safety report in each group.

CONCLUSION

We observed a high rate of adherence to an IV levothyroxine hold guideline. This was associated with a substantial cost savings over the study period with no increase in reported safety events. To our knowledge, this is the first published report of an inpatient IV levothyroxine 3-day hold guideline.

Thyrotoxicosis in patients with COVID-19: the THYRCOV study

OBJECTIVE

This study assessed thyroid function in patients affected by the coronavirus disease-19 (COVID-19), based on the hypothesis that the cytokine storm associated with COVID-19 may influence thyroid function and/or the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may directly act on thyroid cells, such as previously demonstrated for SARS-CoV-1 infection.

DESIGN AND METHODS

This single-center study was retrospective and consisted in evaluating thyroid function tests and serum interleukin-6 (IL-6) values in 287 consecutive patients (193 males, median age: 66 years, range: 27-92) hospitalized for COVID-19 in non-intensive care units.

RESULTS

Fifty-eight patients (20.2%) were found with thyrotoxicosis (overt in 31 cases), 15 (5.2%) with hypothyroidism (overt in only 2 cases), and 214 (74.6%) with normal thyroid function. Serum thyrotropin (TSH) values were inversely correlated with age of patients (rho -0.27; P < 0.001) and IL-6 (rho -0.41; P < 0.001). In the multivariate analysis, thyrotoxicosis resulted to be significantly associated with higher IL-6 (odds ratio: 3.25, 95% confidence interval: 1.97-5.36; P < 0.001), whereas the association with age of patients was lost (P = 0.09).

CONCLUSIONS

This study provides first evidence that COVID-19 may be associated with high risk of thyrotoxicosis in relationship with systemic immune activation induced by the SARS-CoV-2 infection.

Low Yield of Thyroid-Function Tests in Adult Hospitalized Patients - A Retrospective Analysis

BACKGROUND

In the US, serum thyroid-stimulating hormone (TSH) and thyroxine measurements are the fourth- and tenth-commonest laboratory tests ordered, respectively. Diagnosis of thyroid disorder requires clinical suspicion supported by laboratory values. However, in the setting of acute illness, both the clinical and laboratory pictures can be confounded.

OBJECTIVE

To study clinical outcomes and derangement patterns of inpatient thyroid-function tests.

DESIGN

This retrospective study was conducted at an academic center on admissions aged ≥18 years and TSH tests performed over a 1-year period. Admissions with active pregnancy and/or prior thyroid-related diagnosis were excluded.

MAIN OUTCOMES

Clinical outcomes were divided based on new diagnosis of thyroid-related disorder, newly prescribed thyroxine replacement, or antithyroid drugs/ endocrinology referrals, or both. In order to analyze the derangement patterns of abnormal TSH, only the results of the first test ordered were considered (as some admissions had multiple TSH tests ordered).

RESULTS

A total of 7,204 admissions aged ≥18 years had TSH tests done. Of these, 1,912 were excluded. Of the 5,292 admissions with no prior thyroid disorder or active pregnancy, 183 (3.46%) were assigned a new diagnosis of thyroid-related disorder, 54 (1.02%) received treatment/referral, and 46 (0.87%) received both a new diagnosis and treatment/referral. Based on the TSH results (reference range 0.42-4.0 mIU/L) of the 5,292 admissions, 4,312 (81.5%) and 980 (18.5%) admissions were flagged normal and abnormal, respectively. Of the 980 admissions with one or more abnormal TSH results, 21 (2.14%) had first ordered TSH <0.05 mIU/L, 855 (87.25%) admissions had first TSH result between 0.05-10 mIU/L, and lastly 104 (10.61%) were >10 mIU/L.

CONCLUSION

There is low value in testing inpatients for thyroid disorders, and testing comes at significant expense to the health-care system.