Goitre: a cause of obstructive sleep apnoea in euthyroid patients

The impact of thyroidectomy on obstructive sleep apnea: a systematic review and meta-analysis

PURPOSE

Various thyroid pathologies are speculated to contribute to obstructive sleep apnea (OSA). The underlying mechanisms of the intricate relationship between OSA and thyroid structure and function, and whether thyroidectomy can alleviate OSA symptoms remain unclear. An assessment of the impact of thyroidectomy on OSA is warranted.

METHODS

A systematic review of four electronic databases (PubMed (Medline), Embase, the Cochrane library, and ClinicalTrials.gov) was performed up to February 2022. The primary outcomes were preoperative and postoperative Apnea/Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), Berlin questionnaire scores, and continuous positive airway pressure (CPAP) use. A meta-analysis of continuous measures and odd ratios was conducted. Small-scale studies underwent a qualitative meta-analysis.

RESULTS

Six cohort studies on 221 OSA patients who underwent thyroidectomies were included. The results showed that thyroidectomy was associated with significant reduction in postoperative AHI (Mean difference [MD], -6.39, 95% CI, -12.46 to -0.32), however, no significant association was found with CPAP withdrawal (Odd ratio [OR], 0.38, 95% CI, 0.12-1.18). Neither the Berlin questionnaire score (OR, 0.19, 95% CI, 0.03-1.17) nor the ESS improved postoperatively (MD, -1.04, 95% CI, -6.37 to 4.29).

CONCLUSION

This meta-analysis provides a quantitative estimate for the effect of the thyroidectomy on OSA and suggests that thyroidectomy is associated with limited clinical improvement of polysomnographic measures. Future large-scale, well-designed prospective studies are necessary to validate these findings and to refine accordingly the preoperative assessment of both medical conditions individually and in combination.

Neurologic Manifestations of Systemic Disease: Sleep Disorders

Purpose of review

Sleep is intimately involved in overall health and wellbeing. We provide a comprehensive report on the interplay between systemic diseases and sleep to optimize the outcomes of systemic disorders.

Recent findings

Spanning the categories of endocrinologic disorders, metabolic/toxic disturbances, renal, cardiovascular, pulmonary, gastrointestinal, infectious diseases, autoimmune disorders, malignancy, and critical illness, the review highlights the prevalent coexisting pathology of sleep across the spectrum of systemic disorders. Although it is rare that treating a sleep symptom can cure disease, attention to sleep may improve quality of life and may mitigate or improve the underlying disorder. Recent controversies in assessing the cardiovascular relationship with sleep have called into question some of the benefits of treating comorbid sleep disorders, thereby highlighting the need for an ongoing rigorous investigation into how sleep interplays with systemic diseases.

Summary

Systemic diseases often have sleep manifestations and this report will help the clinician identify key risk factors linking sleep disorders to systemic diseases so as to optimize the overall care of the patient.

Prevalence of newly established thyroid disorders in patients with moderate-to-severe obstructive sleep apnea syndrome

BACKGROUND

Hypothyroidism can directly cause obstructive sleep apnea (OSA) but may also contribute to it through its impact on the metabolic syndrome. The purpose of this study was to establish the prevalence of known and newly diagnosed overt and subclinical hypothyroidism (SCH) among patients with OSA.

METHODS

We prospectively included all consecutive moderate or severe OSA patients referred for CPAP therapy. A fasting blood sample was collected to determine thyroid-stimulating hormone (TSH) and free T4 (FT4) levels.

RESULTS

A total of 280 patients were included (70% male). Mean ± SD body mass index (BMI) and apnea-hypopnea index (AHI) were 33 ± 7 kg/m² and 49 ± 25, respectively. Median (range) serum TSH levels and mean ± SD FT4 levels were comparable between severe and moderate OSA (1.7 (1.3-2.6) vs 2.1 (1.2-2.8); p = 0.378 and 15.3 ± 2.3 vs 15.3 ± 2.3; p = 0.981). TSH and FT4 levels were not correlated with AHI (p = 0.297 and p = 0.370, respectively), but TSH was correlated with BMI (p = 0.049).Of all patients, 8.9% had increased serum TSH levels (severe and moderate OSA patients had similar levels (p = 0.711)) and 8.2% were newly diagnosed patients (no differences were observed between severe and moderate OSA (p = 0.450)). A total of 16.4% of patients had some type of thyroid disorder. Thyroid function parameters were associated with BMI but not with the severity of OSA.

CONCLUSION

In our population of moderate or severe OSA, 16% of patients had a thyroid problem and 8% of these were newly diagnosed with SCH.

Therapeutic options for obstructive sleep apnea

Obstructive sleep apnea is a common, chronic disorder characterized by the cessation or reduction in airflow due to periodic mechanical obstruction of the upper airway passage during sleep. Symptoms and signs of sleep apnea include daytime sleepiness, fatigue, poor concentration, snoring, resuscitative snorts, and related occupational accidents. Sleep apnea is classified into 3 types based on its severity and management varies accordingly. The first step in treatment is to identify correctible causes and educate patients on lifestyle modifications. Positive airway pressure is the preferred treatment modality and can be delivered via 3 different modes. Oral appliances are of 3 types and are generally indicated in mild to moderate obstructive sleep apnea. Surgery is a final therapeutic option that focuses on the removal of excessive tissue from different sites of the pharyngeal airway.

Impact of thyroidectomy on the control of obstructive sleep apnea syndrome in patients with large goiters

PURPOSE

A large goiter can cause a series of compressive symptoms such as dyspnea and dysphagia, and previous case reports have indicated the coexistence of obstructive sleep apnea syndrome (OSAS) in these patients. The aim of this study was to evaluate the impact of thyroidectomy on the control of OSAS in patients with large goiters.

METHODS

Twenty-four patients with euthyroid goiters larger than 100 ml were consecutively selected. Of these, 17 (70.8%) presented OSAS and formed the research group. The protocol consisted of sleep questionnaires, physical examination, and polysomnography in baseline and after 3 months of surgery.

RESULTS

The average age of the patients was 58.3±9.9 years, and there were 5 (29.4%) males and 12 (70.6%) females. The significant findings in the postoperative period included a reduced neck circumference (p=0.041), reduced Epworth sleepiness score (p=0.025), decreased percentage of high-risk OSAS cases according to the Berlin questionnaire (p<0.001), and a tendency for a significant reduction in snoring (p=0.052). However, polysomnographic respiratory parameters showed no significant improvement after surgery.

CONCLUSION

Despite the high prevalence of OSAS in patients with large goiters and the improvement of OSAS symptoms, thyroidectomy showed no significant impact on the polysomnographic parameters.

Relationship between obstructive sleep apnea syndrome and thyroid diseases

Obstructive sleep apnea syndrome (OSAS) is a widespread disorder characterized by recurrent, partial, or complete episodes of apnea due to upper airway tract obstruction during sleep. OSAS frequency is likely to increase in hypothyroidism because of obesity, macroglossia, dysfunctional upper respiratory tractus (URT) musculature, deposition of mucopolysaccharides in URT tissues, and decreased ventilatory control. This study examines the relationship between OSAS and thyroid disease in OSAS subjects. This study includes 150 polysomnographically diagnosed OSAS patients (50 mild, 50 moderate, 50 severe OSAS cases) treated at Endocrinology and Metabolism Department of Ankara Numune Training and Research Hospital between January 2010 and May 2011 and 32 non-OSAS control subjects. All patients were given serum TSH, free T3 (fT3), free T4 (fT4), anti thyroid peroxidase (Anti-TPO), and anti-thyroglobulin (anti-TG) tests, as well as thyroid ultrasounds. We did not find any difference in prevalence of hypothyroidism, numbers of nodules and parenchyma heterogenicity determined by ultrasound, between OSAS subgroups and controls (p > 0,05). In this study, functional and ultrasonographic examination of the thyroid gland did not reveal any relationship between OSAS and thyroid disease. We believe hence that long-term follow-up studies can establish the possible significance of routine evaluation of OSAS patients for thyroid disease.

Thyroidectomy decreases snoring and sleep apnea symptoms

BACKGROUND

Patients with goiter often complain of compressive symptoms, which may contribute to symptoms of obstructive sleep apnea (OSA). However, the impact of thyroid enlargement on these symptoms is not clear. Therefore, we sought to evaluate whether symptoms of sleep apnea resolved after thyroidectomy by using a validated questionnaire.

METHODS

The Berlin Questionnaire, a validated sleep apnea assessment tool, was provided to patients at a single academic institution before and after thyroidectomy. Patients who admitted to symptoms of snoring were asked to complete the questionnaire before and 8 weeks after surgery to assess for improvement in symptoms. The questionnaire uses 3 categories of questions to determine risk of sleep apnea. Two symptom categories must be positive for a patient to be considered high risk for sleep apnea.

RESULTS

Forty-five patients completed both pre- and postoperative questionnaires. The average age of patients completing the questionnaire was 53±2 years, and 78% of patients were female. Average body mass index was 33.3±1.4 kg/m(2). Based on their preoperative questionnaire score, 71% of patients were considered to be high risk for OSA, and this decreased to 51% after surgery (p=0.002). Overall scores significantly improved after surgery (mean 2.0 vs. 1.6, p<0.0001). Specifically, patients noted a significant decrease in snoring frequency after surgery (p=0.002), as well as a significant decrease in whether or not their snoring bothered others (p=0.004). The frequency of nodding off during the day also significantly decreased after surgery (p=0.02). Among patients with ≥25% improvement compared with those with <25% improvement in scores, the only significant difference found was a higher preoperative thyrotropin among patients with <25% improvement (p=0.03). No significant difference was found between age, gender, presence of compressive symptoms, gland weight at resection, presence of thyroiditis, or the largest dimension of the gland at resection.

CONCLUSIONS

Thyroid surgery appears to significantly improve symptoms of OSA in patients who screened positive for symptoms before surgery. Evaluation of patients with OSA should include evaluation of thyroid disease, as symptoms of sleep apnea may improve with thyroidectomy.

Thyroidectomy for goiter relieves obstructive sleep apnea: results of 8 cases

The author conducted a retrospective study of 8 adults with euthyroid goiter that had resulted in tracheal compression and led to moderate to severe obstructive sleep apnea (OSA). The purpose of the study was to evaluate the effects of thyroidectomy on the apnea-hypopnea index (AHI) in these patients and to determine if there is a relationship between tracheal compression and OSA. These patients had been treated by the author in a community hospital over a 4-year period. All 8 patients had reported compressive symptoms of orthopnea and dysphagia, and 3 of them also reported dyspnea. Computed tomography of the neck and chest had been used to confirm the extent of goiter and tracheal compression. OSA had been confirmed with preoperative polysomnography. At 90 days post-thyroidectomy, repeat polysomnography had been obtained. At follow-up, all 8 patients had reported symptomatic control of compressive symptoms, and 7 patients had demonstrated postoperative improvement in their AHI. Overall, the mean postoperative AHI had decreased from 52.1 to 36.6-a statistically significant reduction of 29.8% (p < 0.05). The results of this study suggest that thyroidectomy for tracheal compression secondary to goiter can significantly alleviate symptoms and improve AHI in those patients who experience OSA. Evaluation of all patients with OSA should include screening for goiter-induced tracheal compression.

Multinodular thyroid goitre causing obstructive sleep apnoea syndrome

Background:

Obstructive sleep apnoea syndrome has been linked to obesity, nasal obstruction and adenotonsillar hypertrophy, but rarely to large thyroid goitres.

Objective:

To study the possible association between multinodular retrolaryngo-pharyngeal or retrosternal goitres and obstructive sleep apnoea syndrome.

Subjects and methods:

Retrospective case series at a tertiary referral centre (2000–2010). Study parameters included body mass index, Epworth sleep score and polysomnographic index.

Results:

Five patients were diagnosed with obstructive sleep apnoea syndrome and managed with nasal continuous positive airway pressure ventilation. Computed tomography showed a retrolaryngo-pharyngeal or retrosternal goitre with significant tracheal compression, displacement and laryngeal oedema. After total thyroidectomy, obstructive sleep apnoea resolved in all patients.

Conclusion:

Large, multinodular goitres with retrolaryngo-pharyngeal extension can cause obstructive sleep apnoea syndrome due to laryngeal compression and oedema. In such cases, total thyroidectomy enables resolution of symptoms. Patients with obstructive sleep apnoea syndrome should be screened for thyroid goitre.

Endocrine aspects of obstructive sleep apnea

CONTEXT

Some endocrine and metabolic disorders are associated with a high frequency of obstructive sleep apnea (OSA), and treatment of the underlying endocrine disorder can improve and occasionally cure OSA. On the other hand, epidemiological and interventional studies suggest that OSA increases the cardiovascular risk, and a link between OSA and glucose metabolism has been suggested, via reduced sleep duration and/or quality.

EVIDENCE ACQUISITION

We reviewed the medical literature for key articles through June 2009.

EVIDENCE SYNTHESIS

Some endocrine and metabolic conditions (obesity, acromegaly, hypothyroidism, polycystic ovary disease, etc.) can be associated with OSA. The pathophysiological mechanisms of OSA in these cases are reviewed. In rare instances, OSA may be improved or even cured by treatment of underlying endocrine disorders: this is the case of hypothyroidism and acromegaly, situations in which OSA is mainly related to upper airways narrowing due to reversible thickening of the pharyngeal walls. However, when irreversible skeletal defects and/or obesity are present, OSA may persist despite treatment of endocrine disorders and may thus require complementary therapy. This is also frequently the case in patients with obesity, even after substantial weight reduction.

CONCLUSIONS

Given the potential neurocognitive consequences and increased cardiovascular risk associated with OSA, specific therapy such as continuous positive airway pressure is recommended if OSA persists despite effective treatment of its potential endocrine and metabolic causes. "Apropos of sleep, that sinister adventure of all our nights, we might say that men go to bed daily with an audacity that would be incomprehensible if we did not know that it is the result of ignorance of the danger." Charles Baudelaire, in "Fusées, IX"

[Asthma mimic - a clinical case report]

Most mediastinal goiters are extensions of cervical goiters. Patients are generally female and only occasionally have symptoms. Patients most commonly complain of a mass-like sensation, dyspnoea, dysphagia and cough. The authors describe the case of a 67 year-old female who presented at the emergency room with dyspnoea, anterior cervical discomfort and tightness which had onset a few months prior but which had worsened in the last week. The patient cited a history of bronchial asthma, for which she was under medication, but the true diagnosis was mediastinal goiter.

Sleep apnea syndrome in endocrine diseases

It is increasingly recognized that sleep-disordered breathing (SDB) - from snoring to apnea-hypopnea syndrome (SAHS) - can affect patients with various endocrine diseases (ED). Different mechanisms are implied in SDB, promoting either central or, more frequently, obstructive apnea in different ED. In the past, acromegaly and hypothyroidism were first associated with both central and obstructive SAHS. Today, great attention is placed on the complex cause-effect relationship between diabetes mellitus and obstructive SAHS (and vice versa). Symptoms and signs of SAHS may complicate the clinical course of these diseases and should be promptly suspected to detect and possibly treat the accompanying SDB.