Screening for hypothyroidism in sleep apnea

Clinical significance of monitoring hypothyroidism in patients with autoimmune rheumatic disease: a retrospective cohort study

We evaluated whether thyroid function test (TFT) screening is warranted for patients with autoimmune rheumatic diseases (ARD) by comparing the incidence of hypothyroidism requiring treatment (HRT) in ARD patients and healthy controls (HCs). Medical records of 2307 ARD patients and 78,251 HCs for whom thyroid-stimulating hormone (TSH) levels were measured between 2004 and 2018 were retrospectively reviewed. Cumulative incidence of HRT in ARD patients and HCs was compared. HRT development was evaluated with age- and sex-adjusted Kaplan–Meier curve. Risk factors were identified with Cox proportional hazard models. HRT was significantly more common in ARD patients than in HCs (6.3% vs. 1.9%, P < 0.001). After adjusting for age, sex, and baseline TSH level, hazard ratios for HRT were significantly higher in overall ARD patients (hazard ratio [95% confidence interval] 3.99 [3.27–4.87]; P < 0.001), particularly with rheumatoid arthritis and antinuclear antibody-associated diseases in female, and antinuclear antibody-associated diseases, spondyloarthritis, and vasculitis in male patients. Baseline high TSH level, thyroid-related autoantibody positivity, high IgG, and renal impairment were significant risk factors for hypothyroidism development in ARD patients; 20% of high-risk patients developed HRT during follow-up. HRT was significantly more frequent in ARD patients. Careful TFT screening and follow-up could help detecting clinically important hypothyroidism.

Hypothyroidism and Its Association With Sleep Apnea Among Adults in the United States: NHANES 2007-2008

CONTEXT

The association between hypothyroidism and sleep apnea (SA) has been studied, but results are conflicting and based mostly on small studies.

OBJECTIVE

To determine whether there is a positive association between hypothyroidism and SA in the US population.

DESIGN

Cross-sectional study.

SETTING

US National Health and Nutrition Examination Survey, 2007-2008.

PARTICIPANTS

We included all subjects ≥18 years old who met inclusion criteria. Participants not on antithyroid medication with a TSH >5.6 mIU/L and those on thyroid hormone replacement regardless of TSH were categorized as hypothyroid. Participants not on thyroid hormone replacement or antithyroid medication who had a TSH ≥0.34 and ≤5.6 mIU/L were categorized as euthyroid. The diagnosis of SA was based on participants' response when asked whether they had been diagnosed with SA by their doctors.

MAIN OUTCOME MEASURES

Multivariate logistic regression analyses were performed to determine the association between hypothyroidism and SA.

RESULTS

A total of 5515 adults were included for data analysis. The prevalence of hypothyroidism and hyperthyroidism was calculated at 9.47% and 1.19%, respectively. Multivariate logistic regression analysis adjusted for demographics, health care access, body mass index, socioeconomic factors, alcohol use, smoking, and other comorbidities demonstrated a significant association between hypothyroidism and SA (OR = 1.88, 95% CI, 1.24 to 2.84, P < 0.01).

CONCLUSION

Hypothyroidism is associated with SA after adjustment for potential confounding variables.

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

OBJECTIVE

In obstructive sleep apnea (OSA), while both hypothyroidism and hyperthyroidism have been studied, the occurrence of non-thyroidal illness syndrome (NTIS) (normal thyroid stimulating hormone [TSH] with low triiodotironine) has not been investigated. We explored the occurrence of NTIS in patients with moderate to severe OSA and its relationship to the severity of nocturnal respiratory disorders. We also studied the occurrence of subclinical hypothyroidism (SH, ie, high TSH with normal thyroxine) in OSA and changes in circulating TSH, free triiodotironine (fT3) and free thyroxine (fT4) after CPAP treatment.

METHODS

After a nocturnal respiratory polysomnography, 125 consecutive patients with moderate to severe OSA and 60 control subjects with normal nocturnal respiration were recruited. Morning circulating TSH, fT3, and fT4 were measured in all subjects. In a subsample of patients, nocturnal polysomnography and hormonal determinations were repeated after CPAP treatment for five months.

RESULTS

NTIS was found in 13 (10.4%), and SH in ten (8%) OSA subjects, but not in any control subjects. Patients with NTIS showed worse mean nocturnal oxygen saturation and time with saturation <90% (both p < 0.001). After treatment, NTIS subjects (n = 13) showed an increase in fT3 (p < 0.001) to the normal range, and SH subjects (n = 6) a slight decrease in TSH (p = 0.01). In the patients with normal hormones before treatment (n = 45), no change was observed.

CONCLUSIONS

NTIS may occur in OSA patients with severe nocturnal hypoxemia. OSA treatment is followed by an improvement in TSH in patients with abnormal baseline levels of this hormone, and by recovery of NTIS.

Role of hypothyroidism in obstructive sleep apnea: a meta-analysis

OBJECTIVE

This study evaluates the role of hypothyroidism in obstructive sleep apnea (OSA) by comparing the OSA indices in hypothyroid OSA (OSA-HYPOT) with euthyroid OSA (OSA-EUTHY) patients.

METHODS

After literature search in several electronic databases and selection of studies by following eligibility criteria, meta-analyses of mean differences/standardized mean differences were performed to compare OSA indices at the time of diagnosis between OSA-HYPOT and OSA-EUTHY patients. Metaregression analyses were carried out to examine the relationship between age, BMI, sample size, and gender vs OSA indices in OSA-HYPOT patients.

RESULTS

Twelve studies and five case reports recruiting 192 OSA-HYPOT and 1423 OSA-EUTHY patients were included in the meta-analysis. Prevalence (mean ± SD) of clinical hypothyroidism in OSA patients was 8.12 ± 7.13% and that of subclinical hypothyroidism 11.07 ± 8.49%. Apnea-Hypopnea Index, time of sleep with oxygen desaturation <90%, and Epworth Sleepiness Scale were significantly higher in the OSA-HYPOT patients at diagnosis, whereas there was no significant difference in arousal index, respiratory disturbance index and sleeping efficiency between OSA-HYPOT and OSA-EUTHY patients. Body mass index was positively associated with Apnea-Hypopnea Index in OSA-HYPOT patients.

CONCLUSIONS

Hypothyroidism is found to be associated with severity of OSA. However, obesity can be a confounder in the outcomes observed herein.

Low carbohydrate diet-based intervention for obstructive sleep apnea and primary hypothyroidism in an obese Japanese man

BACKGROUND

Obesity is a major risk factor for obstructive sleep apnea (OSA), and weight loss is necessary in the overall management of obese patients with OSA. However, primary care physicians can provide only limited weight loss with lifestyle interventions, usually reducing a patient's body weight by only 2.5 kg or less after 6-18 months.

CASE PRESENTATION

A 45-year-old Japanese man was referred to our clinic owing to obesity, daytime sleepiness, and snoring during sleep. His weight was 130.7 kg and his body mass index (BMI) was 41.0 kg/m(2). He underwent polysomnography, which revealed OSA with an apnea-hypopnea index of 71.2 events/h (normal, <5 events/h). His laboratory results were as follows: thyroid stimulating hormone, >500 μIU/mL; free triiodothyronine, 1.4 pg/mL; free thyroxine, <0.15 ng/dL; thyroid peroxidase antibody, 10 IU/mL; thyroglobulin antibody, >4000 IU/mL; total cholesterol (TC), 335 mg/dL; high-density lipoprotein cholesterol, 45 mg/dL; triglycerides (TGs), 211 mg/dL; low-density lipoprotein cholesterol, 248 mg/dL; fasting blood sugar, 86 mg/dL; and glycated hemoglobin (HbA1c), 6.1 %. These results showed that he also had primary hypothyroidism (Hashimoto's disease). Continuous positive airway pressure (CPAP), levothyroxine replacement, and a low-carbohydrate diet (LCD) were initiated. CPAP use and a euthyroid condition induced by 175 μg/day levothyroxine allowed the patient to proactively reduce his body weight. After 18 months, the patient achieved a weight reduction of 32.4 kg (25 % of his initial weight) and a BMI reduction of 10.2 kg/m(2), as well as improved laboratory results, including an HbA1c level of 5.3 %, TC level of 194 mg/dL, and TG level of 89 mg/dL.

CONCLUSION

An LCD may be an effective intervention for weight loss in obese Japanese patients with OSA. Further studies are needed to investigate the weight loss effect of an LCD compared with a conventional calorie-restricted diet. Hopefully, this case report will help to improve the management of obese Asian patients with OSA who typically consume a higher amount of carbohydrates.

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.

Treatment of obstructive sleep apnea syndrome using radiofrequency-assisted uvulopalatoplasty with tonsillectomy

Radiofrequency surgery was introduced to minimize thermal damage to the tissue. A radiofrequency electrode can be used to make cuts in the free edge of the soft palate like those done in laser-assisted uvulopalatoplasty [radiofrequency-assisted uvulopalatoplasty (RAUP)]. Tonsillectomy can enlarge the lateral diameter of the pharynx. The aim of our study was to evaluate the efficacy of RAUP with tonsillectomy in treatment of obstructive sleep apnea syndrome (OSAS). Ninety-two patients with obstructive sleep apnea were included in this study. Patients were categorized according to disease severity and Friedman's staging system. Patients were assessed with the preoperative visual analog scale (VAS) for snoring, Epworth Sleepiness Scale (ESS) and apnea-hypopnea index (AHI) at baseline and repeated at 6 months postoperatively. The intensity of postoperative pain, speech deficits and dysphagia were also recorded. There was a significant improvement in the VAS score for snoring, ESS and AHI before and after surgery. Overall, the results of the present study indicated a surgery success rate (a 50 % decrease in AHI and AHI <20) of 66 % (61 of 92 patients). Postoperative pain, speech deficits and dysphagia were reduced at 2 weeks after surgery. The results of this study suggest that RAUP with tonsillectomy is an effective treatment for patients with OSAS.

Pulmonary complications of endocrine and metabolic disorders

There are many important respiratory manifestations of endocrine and metabolic diseases in children. Acute and chronic pulmonary infections are the most common respiratory abnormalities in patients with diabetes mellitus, although cardiogenic and non-cardiogenic pulmonary oedema are also possible. Pseudohypoaldosteronism type 1 may be indistinguishable from cystic fibrosis (CF) unless serum aldosterone, plasma renin activity, and urinary electrolytes are measured and mutation analysis rules out CF. Hypo- and hyperthyroidism may alter lung function and affect the central respiratory drive. The thyroid hormone plays an essential role in lung development, surfactant synthesis, and lung defence. Complications of hypoparathyroidism are largely due to hypocalcaemia. Laryngospasm can lead to stridor and airway obstruction. Ovarian tumours, benign or malignant, may present with unilateral or bilateral pleural effusions. Metabolic storage disorders, primarily as a consequence of lysosomal dysfunction from enzymatic deficiencies, constitute a diverse group of rare conditions that can have profound effects on the respiratory system.

The association between severity of obstructive sleep apnea and prevalence of Hashimoto's thyroiditis

Obstructive sleep apnea (OSA) has long been suggested to increase the risk of development of autoimmune diseases. We investigated the prevalence of Hashimoto's thyroiditis (HT) in 245 euthyroid individuals, who were suspected of having OSA. After polysomnography, subjects were grouped according to apnea-hypopnea index (AHI) consecutively as controls (n=27F/32M, AHI<5), mild-OSA (n=22F/37M, 5≤AHI<15), moderate-OSA (n=23F/38M, 15≤AHI<30) and severe-OSA (n=30F/36M, AHI≥30). Diagnosis of HT based on thyroid ultrasound and positivity of serum anti-thyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO) antibodies. Hashimoto's thyroiditis was diagnosed in 32.2% of controls and in 46.8% of all OSA patients (p=0.03). Severe-OSA patients had the highest HT frequency (51.5%) compared to controls (p=0.02), mild-OSA (42.3%, p=0.03) and moderate-OSA (45.9%, p=0.05) groups. Forty-two of control subjects (71.2%) were negative for both of the anti-TPO and anti-TG, whereas 99 (53.2%) of OSA subjects were positive at least for one of them (p=0.01). HT was detected in 62% of females, 29% of males (p<0.001). Severe female OSA patients had the highest HT prevalence (73.3%), while male control subjects had the lowest (18.7%) among all groups (p<0.001). There was no significant correlation between thyroid volume and severity of OSA but isthmus thickness was significantly correlated to AHI (p<0.01, r=0.22). In conclusion, OSA patients presented higher HT prevalence parallel to severity of OSA, especially among women. These results may lead to further investigations about relation between OSA and auto-immune thyroiditis and to development of screening schemas for severe-OSA patients for early diagnosis of HT before development of hypothyroidism.

Addressing obstructive sleep apnea in the emergency department

BACKGROUND

Obstructive sleep apnea (OSA) is a prevalent, serious disease that is under-recognized and under-treated. It results from a combination of increased pharyngeal collapsibility and impaired compensatory pharyngeal muscle dilator activity. OSA causes serious morbidity and mortality. OSA is also a public health problem in that it is an independent cause of car crashes, at great cost to society in dollars and lives. OSA is conservatively estimated to affect 2-4% of Americans; however, recent estimates are much higher.

OBJECTIVES

To educate emergency physicians on the pathophysiology, epidemiology, diagnosis, and management of OSA and discuss diagnostic approaches and recommendations that can be made from the emergency department (ED).

DISCUSSION

Emergency physicians can play an important role in the recognition and referral of patients at risk for OSA. A focused history and physical examination or the use of a structured evaluation can identify patients at risk for OSA. In addition to referring patients at risk for OSA for further diagnostic work-up, emergency physicians can offer recommendations such as weight loss, moderation of alcohol use and certain medications, and smoking cessation.

CONCLUSION

OSA is a common disease in the United States that is under-recognized and under-treated. ED patients who do not regularly see a primary care provider or have no primary care provider are particularly at risk for undiagnosed OSA. Emergency physicians can play an important role in recognizing patients at risk for OSA, referring them for further diagnostic work-up, and offering recommendations from the ED.

Evaluation of Thyroid Gland Function in Children with Obstructive Apnea Hypopnea Syndrome

Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and thyroid function abnormalities, such as hypothyroidism and Hashimoto's thyroiditis, usually have closely resembling clinical features. Differentiation between these disorders is made more difficult because hypothyroid patients are also at risk for secondary sleep-disordered breathing. The aim of our study is to evaluate the prevalence of thyroid function abnormalities in children with OSAHS. Forty-four children (15 females: 29 males), 2.5–14.5 (7.43±2.98) years old were studied with overnight polysomnography. Biochemical screening of thyroid gland function was also carried out. Patients were judged to have OSAHS based mainly on the evaluation of Apnea Hypopnea index per hour of sleep (AHI). 15/44 (34.1%) children had mild OSAHS, 17/44 (38.6%) moderate and 12/44 (27.3%) severe OSAHS. Hypothyroidism was recorded only in 5/44 (11.4%) and Hashimoto's thyroiditis in 3/44 (6.8%) of OSAHS patients. Two patients with hypothyroidism showed mild and three severe OSAHS, while from the 3 children with Hashimoto's thyroiditis one presented mild, one moderate and one severe degree of OSAHS. Although the majority of studies in bibliography worldwide do not consider necessary the systemic evaluation of thyroid gland function in patients with breathing disorders during sleep, it seems that in children this type of screening is required for the differential diagnosis between primary sleep apnea and hypothyroid sleep-disordered breathing in order to differentiate these two conditions. Therefore, the laboratory investigation of thyroid gland function could be considered necessary.

End-tidal CO(2) levels lower in subclinical and overt hypothyroidism than healthy controls; no relationship to thyroid function tests

Background

Hypoventilation is a frequently suspected complication of hypothyroidism.

Objective

In this study we examined the hypothesis that changes in alveolar ventilation, as measured by end-tidal carbon dioxide (Et-CO₂), differ between patients with mild (subclinical) and overt (clinical) thyroid hormone deficiency, and both differ from healthy control subjects.

Methods

A total of 95 subjects, including 33 with subclinical hypothyroidism (an elevated thyroid-stimulating hormone (TSH) level and a normal thyroxin (fT₄) level), 31 with overt hypothyroidism (elevated TSH and decreased fT₄), and 31 healthy controls. All subjects were female and were evaluated clinically by an endocrinologist for evidence of thyroid disease and categorized on the basis of thyroid hormone levels. Et-CO₂ was measured using a capnograph. Et-CO₂ levels were measured three times and the mean value was considered as the mean level for the individual.

Results

Mean Et-CO₂ values of the subclinical hypothyroidism group were significantly lower than those of the healthy controls (31.79 ± 2.75 vs 33.81 ± 2.38; P = 0.01). Moreover, mean Et-CO₂ values for the overt hypothyroidism group were significantly lower than those for healthy controls (32.13 ± 3.07 vs 33.81 ± 2.38; P = 0.04). There was a significant correlation between Et-CO₂ values and TSH levels (r = −0.24; P = 0.01). However, Et-CO₂ values were not correlated with fT₄ levels (r = 0.13; P = 0.20).

Conclusions

Alveolar ventilation, as inferred from lower Et-CO₂ levels, is higher in subjects with subclinical hypothyroidism and overt hypothyroidism (lower Et-CO₂) than in healthy controls. Furthermore, Et-CO₂ levels have no relationship to the levels of TSH or fT₄. The lower Et-CO₂ in these patients with hypothyroidism, particularly at the subclinical stage, suggests presence of hyperventilation, which may be related to direct effect of TRH on respiratory center or to local changes within the lung.

Severe hypothyroidism presenting as obstructive sleep apnea

A 5-year-old child with Down syndrome (DS) diagnosed with mild to moderate obstructive sleep apnea (OSA) and subsequently found to have severe hypothyroidism is presented. Following 3 months of treatment with levothyroxine, she had full resolution of her OSA. This case underscores the importance of routine thyroid function screening in children with DS and demonstrates that OSA in children with DS can be caused by other underlying medical issues that themselves require therapy, such as the hypothyroidism in this child. Although empiric testing of thyroid function is not recommended as part of the routine workup of patients with OSA, when caring for children at higher risk for thyroid dysfunction, such as those with DS, it is important to establish whether or not it is present, as treating it may bring about partial or full resolution of the OSA, as was shown to occur in this patient.

Reversibility of fibrotic appearance of lungs with thyroxine replacement therapy in patients with severe hypothyroidism

OBJECTIVE

To present 2 cases of hypothyroidism with hypoxia associated with computed tomographic (CT) features suggestive of pulmonary fibrosis that resolved with correction of the hypothyroidism.

METHODS

Clinical case histories are described, comparative radiologic pulmonary images before and after treatment are provided, and the pertinent literature regarding possible pathologic mechanisms is reviewed.

RESULTS

Our first patient, a 68-year-old woman, presented with symptomatic severe hypothyroidism associated with respiratory failure. A CT scan of her lungs showed appearances suggestive of pulmonary fibrosis. Replacement therapy with levothyroxine led to correction of hypoxia and radiologic abnormalities. Our second patient, a 26-year-old man, presented with symptoms suggestive of obstructive sleep apnea that persisted despite use of positive pressure ventilation. Biochemical evaluation revealed severe hypothyroidism, and a CT scan disclosed pulmonary appearances consistent with fibrosis. His symptoms and radiologic abnormalities also improved after correction of hypothyroidism with levothyroxine therapy.

CONCLUSION

Radiologic pulmonary abnormalities suggestive of fibrotic disease are associated with severe hypothyroidism. Invasive investigations such as lung biopsy should be deferred until the clinical and radiologic responses to thyroxine replacement therapy have been assessed.

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"

Neuroendocrine alterations in obese patients with sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a serious, prevalent condition that has significant morbidity and mortality when untreated. It is strongly associated with obesity and is characterized by changes in the serum levels or secretory patterns of several hormones. Obese patients with OSAS show a reduction of both spontaneous and stimulated growth hormone (GH) secretion coupled to reduced insulin-like growth factor-I (IGF-I) concentrations and impaired peripheral sensitivity to GH. Hypoxemia and chronic sleep fragmentation could affect the sleep-entrained prolactin (PRL) rhythm. A disrupted Hypothalamus-Pituitary-Adrenal (HPA) axis activity has been described in OSAS. Some derangement in Thyroid-Stimulating Hormone (TSH) secretion has been demonstrated by some authors, whereas a normal thyroid activity has been described by others. Changes of gonadal axis are common in patients with OSAS, who frequently show a hypogonadotropic hypogonadism. Altogether, hormonal abnormalities may be considered as adaptive changes which indicate how a local upper airway dysfunction induces systemic consequences. The understanding of the complex interactions between hormones and OSAS may allow a multi-disciplinary approach to obese patients with this disturbance and lead to an effective management that improves quality of life and prevents associated morbidity or death.

Sleep-related problems in common medical conditions

Common medical problems are often associated with abnormalities of sleep. Patients with chronic medical disorders often have fewer hours of sleep and less restorative sleep compared to healthy individuals, and this poor sleep may worsen the subjective symptoms of the disorder. Individuals with lung disease often have disturbed sleep related to oxygen desaturations, coughing, or dyspnea. Both obstructive lung disease and restrictive lung diseases are associated with poor quality sleep. Awakenings from sleep are common in untreated or undertreated asthma, and cause sleep disruption. Gastroesophageal reflux is a major cause of disrupted sleep due to awakenings from heartburn, dyspepsia, acid brash, coughing, or choking. Patients with chronic renal disease commonly have sleep complaints often due to insomnia, insufficient sleep, sleep apnea, or restless legs syndrome. Complaints related to sleep are very common in patients with fibromyalgia and other causes of chronic pain. Sleep disruption increases the sensation of pain and decreases quality of life. Patients with infectious diseases, including acute viral illnesses, HIV-related disease, and Lyme disease, may have significant problems with insomnia and hypersomnolence. Women with menopause have from insomnia, sleep-disordered breathing, restless legs syndrome, or fibromyalgia. Patients with cancer or receiving cancer therapy are often bothered by insomnia or other sleep disturbances that affect quality of life and daytime energy. The objective of this article is to review frequently encountered medical conditions and examine their impact on sleep, and to review frequent sleep-related problems associated with these common medical conditions.

Pharmacotherapy of obstructive sleep apnea

Obstructive sleep apnea (OSA) is associated with serious comorbid illnesses and diminished quality of life. At this time, continuous positive airway pressure (CPAP) therapy is the treatment of choice. However, only half of those individuals who accept CPAP are still using it at the end of one year. Furthermore, efficacy for improving self-reported sleepiness appears to be greater for patients with severe sleep apnea and severe sleepiness than other patient groups. Some patients, notwithstanding optimized therapy and therapeutic adherence continue experiencing excessive daytime somnolence. Consequently, other treatment modalities have developed, including oral appliances, surgery and pharmacotherapy. It is widely believed, albeit not empirically demonstrated, that an effective medication to treat OSA would elicit better acceptance and adherence than having to use a machine for many hours on a nightly basis. Nonetheless, paucity of data (i.e. lack of large-scale randomized controlled trials), variability of perceived and actual benefits, and adverse side-effects of the drugs thus far tested have prevented the use of pharmacotherapy until now. In this paper we review the outcome data from published trials designed to evaluate efficacy and safety of various medications proposed for treating obstructive sleep apnea.

Recognizing and managing obstructive sleep apnea in primary care

OBJECTIVE

This review aims to impart information regarding recognition of obstructive sleep apnea (OSA) and associated excessive sleepiness (ES) in the primary care setting in order to provide optimal care to patients with this common but serious condition. This review will also discuss the prevalence and treatment of depression in patients with OSA.

DATA SOURCES

A MEDLINE search of articles published between 1990 and 2008 was conducted using the search terms obstructive sleep apnea AND excessive sleepiness, obstructive sleep apnea AND depression, and obstructive sleep apnea AND primary care. Searches were limited to articles in English concerned with adult patients.

STUDY SELECTION

In total, 239 articles were identified. Articles concerning other sleep disorders and forms of apnea were excluded. The reference lists of identified articles were searched manually to find additional articles of interest.

DATA SYNTHESIS

Primary care physicians can aid in the diagnosis of OSA and associated ES by being vigilant for lifestyle and physical risk factors associated with this condition. In addition, primary care physicians should maintain a high level of clinical suspicion when presented with illnesses that are commonly comorbid with OSA, such as psychiatric disorders and depression, in particular. Conversely, assessment of patients with OSA for common comorbidities may also improve a patient's prognosis and quality of life.

CONCLUSIONS

Primary care physicians play a vital role in recognizing OSA and ES. These clinicians are crucial in supporting their patients during treatment by ensuring that they have clear, concise information regarding available therapies and the correct application and maintenance of prescribed devices.

Obstructive sleep apnea in older adults

The "typical" presentation of obstructive sleep apnea (OSA) is chronic loud snoring and excessive daytime sleepiness in middle-aged obese men. OSA can result in increased risk for cardiovascular morbidity and mortality. The diagnostic features of OSA in older adults are similar to those in younger adults; however, the older adult may be less likely to seek medical attention or have the sleep disorder recognized because symptoms of snoring, sleepiness, fatigue, nocturia, unintentional napping, and cognitive dysfunction may be ascribed to the aging process itself or to other disorders. This article reviews the basic terminology and pathophysiology of sleep-disordered breathing, discusses why OSA may be even more prevalent in older adults than in the middle-aged group, and reviews similarities and differences between the two groups in the manifestations, consequences, and treatments of OSA.

[Anaesthetic management of adult patients with obstructive sleep apnea syndrome]

OBJECTIVE

The purpose of this review article is to update the anaesthetic management of adult patients with obstructive sleep apnoea syndrome (OSAS).

DATA SOURCES

All references obtained from the medical database Medline related to OSAS and anaesthesia from 1963 until May 2006 were reviewed. References included original articles, observations, clinical cases, and reviews published in English or in French.

DATA SYNTHESIS

The anaesthetic literature related to OSAS and anaesthesia is poor. Understanding anatomy and pathophysiology is important for an optimal anaesthetic management. Since the diagnosis is unknown in almost 80-90% of these patients, many undergo general or regional anaesthesia every day without recognition of the main dangers associated with the condition. Recognition of these patients, especially in the preanaesthetic assessment, is an essential step to prevent perioperative complications. Patients with OSAS are very sensitive to sedatives, hypnotics and opioids. The use of these drugs must be controlled and monitored. Anticipation of difficult intubation avoids complications during induction of general anaesthesia and the use of nasal CPAP decreases the incidence of respiratory complications in the perioperative period.

CONCLUSION

Further research is needed in this field of anesthesia. Intraoperative difficulties in the control of airway and postoperative cardiac and respiratory complications may happen. The use of nasal CPAP in the perioperative period makes the anaesthetic management easier and safer.

Influence of subclinical hypothyroidism and T4 treatment on the prevalence and severity of obstructive sleep apnoea syndrome (OSAS)

BACKGROUND

Obstructive sleep apnoea (OSA) and subclinical hypothyroidism are relatively frequent disorders that may be causally linked. However, discordant results exist on the prevalence and severity of OSA in subclinical hypothyroidism. The aim of this study was to compare the prevalence and severity of sleep-disordered breathing in individuals with or without subclinical hypothyroidism, and to investigate the possible effect of levothyroxine treatment on these patients.

PATIENTS AND METHODS

One hundred and eight subjects were consecutively enrolled and divided in 3 groups, according to the TSH levels and levothyroxine therapy. The first group (Group A) was represented by 63 subjects with normal TSH and thyroid function. The other two groups included patients affected by subclinical hypothyroidism; one group (Group B) treated with levothyroxine, while the other group (Group C) was never treated with levothyroxine. Anthropometric, respiratory and polysomnographic data were evaluated in all individuals.

RESULTS

The percentage of OSA, neck circumference, and body mass index (BMI) were not statistically different among the 3 groups. Respiratory disturbance index (RDI) as well as the percentage of the total number of events (apnoea-hypopnoea) by total sleep time (TST) with <90% oxyhemoglobin saturation (TSTSaO2 <90%) were not different among the groups. When we observed OSA patients, the only significant difference between groups B and C was represented by the Epworth Sleepiness Scale (ESS) (p=0.005).

CONCLUSION

This study shows that subclinical hypothyroidism and treatment with levothyroxine do not influence the prevalence and severity of OSA, while sleep propensity is increased by untreated subclinical hypothyroidism.

Neuroendocrine changes in sleep apnea

PURPOSE OF REVIEW

To review recent investigations examining the effects of neuroendocrine changes in obstructive sleep apnea.

RECENT FINDINGS

Gonadal hormones have long been implicated in the pathogenesis of obstructive sleep apnea. Recently, exogenous testosterone has been shown to exacerbate obstructive sleep apnea, whereas hormone replacement therapy in menopausal women may be protective in obstructive sleep apnea. Effective treatment of obstructive sleep apnea with nasal continuous positive airway pressure has been associated with improved insulin sensitivity and testicular function in individuals with obstructive sleep apnea.

SUMMARY

It is important to consider the potential development of sleep apnea in any patient who has an endocrine disorder or is receiving certain hormonal therapies. Effective assessment and management of obstructive sleep apnea with nasal continuous positive airway pressure may lead to a reduction in insulin resistance and hypertension as well as other markers of vascular risk in patients with metabolic syndrome.

Obstructive Sleep Apnoea in the Elderly

Obstructive sleep apnoea is characterised by repetitive interruptions of breathing during sleep due to upper airway collapse. It affects sleep quality, daytime alertness and quality of life. It is associated with increased cardiovascular morbidity and mortality and an increased risk of road traffic accidents. Sleep apnoea is common among older people and its effects can be more severe than in younger people. The added impact is because of a physiological decline in sleep quality with age in most people and the increasing frequency of other comorbidities with increasing years that affect both sleep and daytime function. It is important to be alert to the diagnosis, bearing in mind these other influences on sleep quality. The diagnosis is generally straightforward once appropriate tests are performed. Treatment is aimed at minimising upper airway obstruction during sleep and the most effective therapy is continuous positive airway pressure. Weight loss can also be effective. Other management options, including surgery, mandibular advancement devices and drug treatment, are less effective, but there are interesting advances in the understanding of the pharmacology of the upper airway. Specific serotonergic agonists hold the greatest potential for a useful drug treatment for this widespread and debilitating condition.

Endocrine effects of nasal continuous positive airway pressure in male patients with obstructive sleep apnoea

OBJECTIVE

Obstructive sleep apnoea (OSA) is a relatively common condition producing disabling somnolence and profound physiological responses to hypoxaemic episodes during sleep, including significant oscillations in blood pressure. This study aimed to provide controlled data on the interaction between OSA and endocrine axes to establish whether overrepresentation of pathology such as hypertension and hypogonadism in OSA subjects might have an endocrine basis.

DESIGN, SETTING AND SUBJECTS

Parallel randomized sham placebo controlled 1-month trial of nasal continuous positive airway pressure (nCPAP) in 101 male subjects with OSA presenting to a respiratory sleep clinic.

METHODS

Analysis of gonadotrophins, testosterone, sex hormone binding protein (SHBG), prolactin, cortisol, thyroid stimulating hormone (TSH), free thyroxine (free T4), insulin-like growth factor-1 (IGF-1), renin and aldosterone were performed at baseline and after 1 month's active or placebo nCPAP intervention. Quality of life questionnaire scoring was also recorded over the same time period.

RESULTS

Testosterone and SHBG showed significant negative correlations with baseline OSA severity. Active treatment of OSA produced SHBG elevation and TSH reduction (P< or =0.03). Both groups showed an increase in aldosterone (P<0.001) and IGF-1 (P< or =0.03), associated with a large improvement in subjective quality of life scoring.

CONCLUSIONS

These findings demonstrate significant changes in endocrine axes not previously reported in a placebo-controlled trial. OSA is a recognized reversible cause of testosterone reduction; SHBG suppression correlating to baseline OSA severity supports a diagnosis of secondary hypogonadism. Significant rises in aldosterone and IGF-1 on treatment coincide with increased physical activity and an improved quality of life score.

Behavioral and pharmacologic therapy of obstructive sleep apnea

Previous attempts at using pharmacologic agents in the treatment of OSA have been disappointing. Medroxyprogesterone has not been found to be useful in the treatment of OSA. Use of protriptyline is limited by frequent side effects, but its role in mild and REM-related OSA must be clarified. SSRIs seem to be ineffective in treatment of severe OSA. Further studies are needed to determine their effect in persons with mild disease. This is important because patients with mild OSA (AHI < 15 hours) are most likely to be noncompliant with CPAP therapy [91]. A recent systematic review of drug treatments for OSA concluded that the current data do not support the use of any drug as an alternative to CPAP [92]. Of 56 studies identified, only 9 studies met methodologic criteria. Clearly, basic research and adequately powered clinical trials are needed to identify an effective medication for OSA.

Treatment of simple snoring using radio waves for ablation of uvula and soft palate: a day-case surgery procedure

OBJECTIVE

Uvulopalatoplasty, performed with high-frequency radio waves, was evaluated as a treatment for social snoring.

METHODS

Forty male social snorers were included in this prospective, nonrandomized study. Patients' subjective complaints before, during, and 3 months after radio-assisted uvulopalatoplasty were recorded on a visual analogue scale.

RESULTS

Complications were negligible. Snoring sounds and daytime tiredness reduced significantly. Considering effect and suffering during and after surgery, a high number of patients (93%) were willing to undergo the procedure again if necessary.

CONCLUSIONS

The results of radio-assisted uvulopalatoplasty (RAUP) seem to be similar to other surgical methods used to reduce snoring. The relative small investments needed and its simplicity makes RAUP a good alternative to known treatment strategies.

Epidemiology and pathogenesis of sleep-disordered breathing

Sleep-disordered breathing is common in the general population, but the observed prevalence depends on the criteria used to establish the diagnosis. Obesity is a strong risk factor, but other conditions such as allergic upper and lower airways disease may also be important. Differences in risk between the sexes and ethnic groups appear to be present even after established risk factors have been considered. The pathogenesis is likely mutifactorial with anatomic and physiologic factors of varying importance in different individuals. The natural history is uncertain, but without treatment or reduction in risk factors, some progression is likely. Ongoing epidemiologic investigations such as the Sleep Heart Health Study are beginning to provide important information on these questions.

CLINICAL REVIEW ARTICLE: Epidemiology of sleep-related obstructive breathing

The diagnosis of obstructive sleep apnoea syndrome (OSAS) and upper airway resistance syndrome (UARS) is based both on a combination of laboratory findings from whole-night sleep recordings and daytime symptoms. Due to the recent interest in breathing disturbances during sleep many prevalence studies have been performed within this field. There are, however, methodological difficulties in characterizing these syndromes in large populations; many of the studies have therefore been unable to present an overview of the complete syndromes but rather have focused on specific characteristics. In epidemiological research snoring and/or daytime sleepiness have often been used as markers of OSAS, while other studies have looked only on the respiratory disturbances or oxygen desaturation. Studies on the prevalence of OSAS based on polysomnography are reviewed here, as well as investigations where associated factors such as cardiovascular diseases and mortality were analysed. The interrelationships between snoring, daytime symptoms and laboratory findings are discussed. Gender, age, obesity, smoking, alcohol and ethnicity are all factors that influence the prevalence of OSAS. The data on associations between OSAS and cardiovascular disease or mortality are sometimes unrelated. Much of the discrepancy between different studies can be explained by the methodological difficulties connected with the definition of OSAS and also by the fact that the association between sleep-disordered breathing and cardiovascular outcome seems to be age-dependent.