Abnormal thyroid hormones and non-thyroidal illness syndrome in obstructive sleep apnea, and effects of CPAP treatment

The hypothalamus–pituitary–thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTIS) or thyroid allostasis in critical illness, tumors, uremia, and starvation (TACITUS), commonly observed in hospitalized patients, displays a historically well-studied pattern of allostatic thyroid response. This is characterized by decreased total and free thyroid hormone concentrations and varying levels of thyroid-stimulating hormone (TSH) ranging from decreased (in severe cases) to normal or even elevated (mainly in the recovery phase) TSH concentrations. An acute versus chronic stage (wasting syndrome) of TACITUS can be discerned. The two types differ in molecular mechanisms and prognosis. The acute adaptation of thyroid hormone metabolism to critical illness may prove beneficial to the organism, whereas the far more complex molecular alterations associated with chronic illness frequently lead to allostatic overload. The latter is associated with poor outcome, independently of the underlying disease. Adaptive responses of thyroid homeostasis extend to alterations in thyroid hormone concentrations during fetal life, periods of weight gain or loss, thermoregulation, physical exercise, and psychiatric diseases. The various forms of thyroid allostasis pose serious problems in differential diagnosis of thyroid disease. This review article provides an overview of physiological mechanisms as well as major diagnostic and therapeutic implications of thyroid allostasis under a variety of developmental and straining conditions.

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“…Several studies have demonstrated that treatment of the underlying disease can aid in the resolution of NTIS (422, 423). …”

Section: Treatment Of Low-t3 Syndrome In Tacitus—an Open Questionmentioning

confidence: 99%

Thyroid Allostasis–Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

Hoermann²,

et al. 2017

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“…In addition, oxidative stress and low-grade inflammation, resulting from OSA, can also contribute to the association between OSA and NTIS (303,304). CPAP for 5 months has been shown to improve FT3 levels in patients with NTIS supporting the notion that OSA might lead to NTIS, but this study was not controlled (301). However, it is important the clinicians take into account the possibility of NTIS when interpreting thyroid function results in patients with OSA.…”

Section: Osa and Non-thyroidal Illness Syndrome (Ntis)mentioning

confidence: 92%

“…A recent cross-sectional study showed that patients with moderate-to-severe OSA (n = 125) had a higher prevalence of NTIS (defined as normal TSH and low FT3) compared to controls (n = 60) (10.4 vs 0%), but the control group was lean, and there were more men in the OSA group (301). Within the OSA group, patients with NTIS had worse nocturnal hypoxemia compared to patients without NTIS (301). This suggests that IH could play a role in the high prevalence of NTIS in patients with OSA, possibly via downregulation of deiodinase 1 and enhancing deiodinase 3-inactivating T3 and T4 (302).…”

Section: Osa and Non-thyroidal Illness Syndrome (Ntis)mentioning

confidence: 99%

Section: Osa and Non-thyroidal Illness Syndrome (Ntis)mentioning

confidence: 99%

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MECHANISMS OF ENDOCRINOLOGY: Mechanisms of disease: the endocrinology of obstructive sleep apnoea

Lavrentaki

Ali

Cooper

et al. 2019

European Journal of Endocrinology

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Obstructive sleep apnoea (OSA) is a common disorder that is associated with serious comorbidities with a negative impact on quality of life, life expectancy and health costs. As OSA is related to obesity and is associated with sleep disruption, increased inflammation and oxidative stress, it is not surprising that OSA has an impact on the secretion of multiple hormones and is implicated in the development of many endocrine conditions. On the other hand, many endocrine conditions that can affect obesity and/or upper airways anatomy and stability have been implicated in the development or worsening of OSA. This bidirectional relationship between OSA and the endocrine system has been increasingly recognised in experimental and epidemiological studies and there are an increasing number of studies examining the effects of OSA treatment on endocrine conditions and vice versa. In this review article, we will critically appraise and describe the impact of OSA on the endocrine system including obesity, dysglycaemia, the pituitary, the thyroid, the adrenals, the reproductive system and the bones. In each section, we will assess whether a bidirectional relationship exists, and we will describe the potential underlying mechanisms. We have focused more on recent studies and randomised controlled trials where available and attempted to provide the information within clinical context and relevance.

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“…[3] Many authors have proposed a correlation of the disease or disease severity with a variety of inflammatory mediators, [4][5][6][7] biochemical markers, [8][9][10] and hormonal parameters. [11][12][13] Some studies have emphasized a correlation of the disease with respiratory tract anatomy and loss of genioglossus and pharyngeal muscle function causing pharyngeal collapse in individuals, although it is not possible to explain the problem with a single mechanism. [3,14] Previous studies investigating the correlation between ethnicity and OSAS have reported craniofacial anatomic features are associated with OSAS development as much as general body and soft tissue features; however, this correlation is clear in the Caucasian race, while there is less correlation among African-Americans.…”

mentioning

confidence: 99%

The role of the external nasal measures of patients with sleep disordered breathing in determining disease severity

Avcu¹

2020

tr-ent

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Objectives: In this study, we aimed to investigate the influence of nasal anthropometric measurements on severity of obstructive sleep apnea syndrome (OSAS) and to assess the correlation between nasal anthropometric measurements and severity of OSAS after excluding internal factors causing nasal obstruction. Patients and Methods: A total of 241 consecutive patients (181 males, 60 females; mean age 50.3±11.3 years; range, 18 to 65 years) with daily sleepiness and/or snoring complaints between February 1 st 2018 and December 15 th 2018 were included in the study. All patients were divided into eight groups as obese and non-obese according to the disease severity and BMI values. Results: According to the obese and non-obese groups, none of the anthropometric measurements in the obese group were correlated with OSAS, while only nasal width (r: 0.282, p=0.001), nasal tip height (r: 0.235, p=0.008), and alar-pronasal distance (r: 0.156, p=0.031) were found to be correlated in the non-obese patient groups. Linear regression analysis of variables which appeared to correlate with the OSAS severity revealed that no variables except for age and BMI significantly contributed to the OSAS severity in the obese group. For the non-obese group, in addition to age and BMI values, nasal width significantly contributed to the disease severity. Conclusion: Although there are many factors in the etiology of OSAS, no external nasal anatomic measurement, except for the nasal width, seems to be correlated with the disease severity.

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Abnormal thyroid hormones and non-thyroidal illness syndrome in obstructive sleep apnea, and effects of CPAP treatment

Cited by 21 publications

References 28 publications

Thyroid Allostasis–Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

Thyroid Allostasis–Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

MECHANISMS OF ENDOCRINOLOGY: Mechanisms of disease: the endocrinology of obstructive sleep apnoea

The role of the external nasal measures of patients with sleep disordered breathing in determining disease severity

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