Differences in Polysomnographic and Craniofacial Characteristics of Catathrenia Phenotypes: A Cluster Analysis.

Purpose: Catathrenia is a rare sleeping disorder characterized by repetitive nocturnal groaning during prolonged expirations. Patients with catathrenia had heterogeneous polysomnographic, comorbidity, craniofacial characteristics, and responses to treatment. Identifying phenotypes of catathrenia might benefit the exploration of etiology and personalized therapy. Patients and Methods: Sixty-six patients diagnosed with catathrenia by full-night audio/video polysomnography seeking treatment with mandibular advancement devices (MAD) or continuous positive airway pressure (CPAP) were included in the cohort. Polysomnographic characteristics including sleep architecture, respiratory, groaning, and arousal events were analyzed. Three-dimensional (3D) and 2D craniofacial hard tissue and upper airway structures were evaluated with cone-beam computed tomography and lateral cephalometry. Phenotypes of catathrenia were identified by K-mean cluster analysis, and inter-group comparisons were assessed. Results: Two distinct clusters of catathrenia were identified: cluster 1 (n=17) was characterized to have more males (71%), a longer average duration of groaning events (18.5±4.8 and 12.8±5.7s, p=0.005), and broader upper airway (volume 41,386±10,543 and 26,661±6700 mm3, p<0.001); cluster 2 (n=49) was characterized to have more females (73%), higher respiratory disturbance index (RDI) (median 1.0 [0.3, 2.0] and 5.2 [1.2, 13.3]/h, p=0.009), more respiratory effort-related arousals (RERA)(1 [1, 109] and 32 [13, 57)], p=0.005), smaller upper airway (cross-sectional area of velopharynx 512±87 and 339±84 mm2, p<0.001) and better response to treatment (41.2% and 82.6%, p=0.004). Conclusion: Two distinct phenotypes were identified in patients with catathrenia, primary catathrenia, and catathrenia associated with upper airway obstruction, suggesting respiratory events and upper airway structures might be related to the etiology of catathrenia, with implications for its treatment.

Mandibular advancement device as treatment trial for catathrenia (nocturnal groaning).

STUDY OBJECTIVES: Catathrenia is a rare disease, classified as isolated symptoms and normal variants under sleep-related breathing disorders in the International Classification of Sleep Disorders, third edition. Because of its rarity, the research on its pathogenesis and treatment is insufficient. This study aimed to evaluate whether the mandibular advancement device (MAD) could be considered an alternative treatment trial and if so, to explore factors predicting its effectiveness. METHODS: Thirty patients (12 men and 18 women, aged 16-67 years) with catathrenia participated in the study. They underwent standard clinical evaluation, questionnaires, physical examinations, craniofacial evaluations, video polysomnography, and imaging of the upper airway before and after the insertion of the MAD. The groaning index (groaning episodes per hour of sleep) and apnea-hypopnea index were evaluated, and anatomic factors predicting effectiveness were explored. RESULTS: The sleep efficiency of most patients was higher than 80%, and groaning was present throughout all stages of sleep. With the insertion of the MAD, the groaning index decreased significantly from 5.8 (2.7-14.3) to 2.8 (1.3-12.2) events/h (P = .014). Age had a negative effect on efficacy. Mandibular repositioning of the MAD, especially the amount of vertical opening and changes of the cross-sectional area of the hypopharynx, was positively related with efficacy. CONCLUSIONS: The MAD could be considered a possible treatment trial for those seeking treatment for groaning. CLINICAL TRIAL REGISTRATION: Registry: Chinese Clinical Trial Register; Name: The etiology of catathrenia based on oral and maxillofacial system; URL: http://www.chictr.org.cn/showproj.aspx?proj=22286; Identifier: ChiCTR-COC-17013239. CITATION: Yu M, Hao Z, Xu L, Wen Y, Han F, Gao X. Mandibular advancement device as treatment trial for catathrenia (nocturnal groaning). J Clin Sleep Med. 2021;17(9):1767-1776.

Impact of mandibular advancement device therapy on cerebrovascular reactivity in patients with carotid atherosclerosis combined with OSAHS.

PURPOSE: Obstructive sleep apnea-hypopnea syndrome (OSAHS) may affect cerebrovascular reactivity (CVR), representing cerebrovascular endothelial function, through complex cerebral functional changes. This study aimed to evaluate the change of CVR after 1-month and 6-month mandibular advancement device (MAD) treatment of patients with carotid atherosclerosis (CAS) combined with OSAHS. METHODS: Patients with carotid atherosclerosis combined with OSAHS who voluntarily accepted Silensor-IL MAD therapy were prospectively enrolled. All patients underwent polysomnographic (PSG) examinations and CVR evaluation by breath-holding test using transcranial Doppler ultrasound at baseline (T0), 1 month (T1), and 6 months (T2) of MAD treatment. RESULTS: Of 46 patients (mean age 54.4 ± 12.4 years, mean body mass index [BMI] 27.5 ± 4.5 kg/m2), 41 patients (responsive group) responded to the 1-month and 6-month treatment of MAD, an effective treatment rate of 89%. The remaining 5 patients (non-responsive group) were younger (47.4 ± 13.5 years) and had a higher BMI (35.8 ± 1.8 kg/m2). The responsive group had an improvement of apnea-hypopnea index (AHI) (events/h) from 33.0 ± 25.0 (T0) to 12.4 ± 10.4 (T1) and 8.7 ± 8.8 (T2), P < 0.001; minimum arterial oxygen saturation (minSpO2) (%) increased from 79.8 ± 9.1 (T0) to 81.8 ± 9.4 (T1) and 85.2 ± 5.4 (T2), P < 0.01; longest apnea (LA) (s) decreased from 46.5 ± 23.1 (T0) to 33.3 ± 22.7 (T1) and 29.4 ± 18.5 (T2), P < 0.001; T90 (%) decreased from 10.3 ± 14.9 (T0) to 6.1 ± 11.8 (T1) and 3.3 ± 7.5 (T2), P < 0.05. Sleep architecture of these patients also improved significantly. The responsive group had a significant increase in left, right, and mean breath-holding index (BHI): left BHI(/s) from 0.52 ± 0.42 (T0) to 0.94 ± 0.56 (T1) and 1.04 ± 0.64 (T2), P < 0.01; right BHI(/s) from 0.60 ± 0.38 (T0) to 1.01 ± 0.58 (T1) and 1.11 ± 0.60 (T2), P < 0.01; mean BHI(/s) from 0.56 ± 0.38 (T0) to 0.97 ± 0.55 (T1) and 1.07 ± 0.59 (T2), P < 0.01), suggesting improved CVR. CONCLUSION: Effective MAD therapy is beneficial for restoring cerebrovascular endothelial function in patients with CAS and OSAHS in a short period (1 month and 6 months). TRIAL REGISTRATION: Clinical trial registration number: NCT03665818. September 11, 2018.

The differences of carotid atherosclerosis among non-OSAHS and OSAHS patients of different severities: a cross-sectional study.

BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a widely prevalent problem with many complications, such as hypertension and cerebral vascular diseases. Atherosclerosis, whose most severe outcome is ischemic stroke, is reported being affected by OSAHS. The objective of this article is to investigate the differences of carotid atherosclerosis patients with or without OSAHS by a cross-sectional research. MATERIALS AND METHODS: Patients diagnosed with carotid atherosclerosis by ultrasonography were recruited. They were requested to fill the primary screening OSAHS questionnaire. Patients with high tendency of OSAHS underwent polysomnography (PSG) tests into OSAHS group, and patients without OSAHS were into non-OSAHS group. Blood tests and medical history were collected. Carotid atherosclerosis severity was analyzed by carotid artery intima-media thickness (IMT), carotid plaque, blood flow velocity, etc. Differences between the two groups and subgroups were analyzed. RESULTS: A total of 242 carotid atherosclerosis patients were enrolled including 118 non-OSAHS patients (38 males and 80 females) and 124 OSAHS patients (40 mild, 32 moderate, and 52 severe). Significant differences were found in PSV-ICA and EDV-ICA on both sides (p < 0.05) but no significant differences on IMT and velocity of CCV. CA patients with OSAHS were younger than ones without OSAHS. With the severity of OSAHS increasing, the age of CA patients decreased. The more severity of OSAHS, the younger the patients were. There were no significant differences in comparing cholesterol, triglyceride, HDL, LDL, and glucose. CONCLUSION: As far as CIMT, carotid plaque, blood flow velocity, and blood lipid are concerned, the severity of CA is not affected by the severity of OSAHS accordantly. The relationship between OSAHS and CA may not be dose dependent. TRIAL REGISTRATION: This study has been registered on clinical trials (No. NCT03665818).

Anatomical characteristics of catathrenia (nocturnal groaning) in upper airway and orofacial structures.

BACKGROUND: Catathrenia is a rare sleep disorder characterized by repeated groaning in a protracted expiration preceded by a deep inspiration. This study aimed to explore whether anatomy is one of pathophysiology of catathrenia by investigating the anatomical features associated with catathrenia in the upper airway, craniofacial structures, and dental patterns. MATERIAL AND METHODS: Twenty-two patients with catathrenia (7 males, 15 females; age 22 to 69 years) were recruited as well as 66 patients matched by age and gender (matching proportion 1:3) with obstructive sleep apnea syndrome (OSAS). Both groups underwent cephalograms and dental casting, and cephalometric measurements and the Peer Assessment Rating (PAR) index was applied. Differences between the two groups were evaluated and cephalometric measurements in catathrenia group were compared with control values of Chinese patients from previous studies. RESULTS: As for airway-related measurements, increased PNS-R, PNS-UPW, and H-FH and decreased SPT and TGL were found in catathrenia group compared to normal values. Such trends were found even more evident when compared with the OSAS Group. As for craniofacial parameters, values of U1/NA and U1/SN were found increased in the catathrenia group compared with normal values and values of MP/FH and Y decreased. The differences were more distinct from the OSAS Group. Increased arch lengths and upper inter-first molar widths, and decreased overbite and PAR index, were found in catathrenia group compared with the OSAS Group. CONCLUSION: Catathrenia patients present with a broad upper airway, yet protrusive upper incisors and flat mandibular angles. Anatomical characteristics of catathrenia are different from those associated with OSAS, namely a wide airway, large skeleton, and good occlusion.